Dept of Physics

DEPT OF PHYSICS

Researcher : Bao Y

List of Research Outputs

Bao Y., Zhuang H., Shen S.Q. and Zhang F.C., Edge spin current and spin polarization in quantum Hall regime, Physical Review B. New York, The American Physical Society, 2005, 72: 245323:1-5.

Bao Y., Resonant spin Hall effect in two-dimensional electron systems. Hong Kong, The University of Hong Kong, 2005, 1-91.

Researcher : Beling CD

Project Title:	Centre for optical and positron characterization of defects
Investigator(s):	Beling CD, Fung SHY, Ling FCC
Department:	Physics
Source(s) of Funding:	Central Allocation Vote - Major Equipment Project
Start Date:	03/2001

Abstract:

To provide the University of Hong Kong with a well-equipped center for studying point defects in semiconductor and other industrially related materials - a center that's expertise and equipment would also be made available to other universities in Hong Kong according to need.

Project Title:	Developing VE-PALS (variable energy positron annihilation lifetime spectroscopy)
Investigator(s):	Beling CD
Department:	Physics
Source(s) of Funding:	Seed Funding Programme for Basic Research
Start Date:	10/2002

Abstract:

To set up a means of taking PALS spectra on solid-state samples using the HKU magnetically guided positron beam.

Project Title:	Studies on positron field assisted moderation
Investigator(s):	Beling CD, Ling FCC
Department:	Physics
Source(s) of Funding:	Competitive Earmarked Research Grants (CERG)
Start Date:	09/2003
Completion Date:	08/2005

Abstract:

To make some positive step towards achieving a successful Positron Field Assisted Moderator (PFAM) by carrying out studies on clean initmate metal-semiconductor junctions; to conduct PFAM investigations only on the following semiconductor substrates: GaAs, GaN and Sic possibly using semi-insulating forms of material; to use the most advanced diagnostic positron spectroscopy techniques, including Coincidence Doppler Broadening Spectroscopy (CDBS) to study any adverse positron trapping at the metal-semiconductor interface.

Project Title:	Studies on positron field assisted moderation
Investigator(s):	Beling CD, Ling FCC
Department:	Physics
Source(s) of Funding:	Merit Award for RGC CERG Funded Projects
Start Date:	09/2003

Abstract:

N/A

Project Title:	Developing Variable Energy Positron Annihilation Lifetime Spectroscopy
Investigator(s):	Beling CD
Department:	Physics
Source(s) of Funding:	Competitive Earmarked Research Grants (CERG)
Start Date:	09/2004

Abstract:

To make some positive step towards achieving a successful Positron Field Assisted Moderator (PFAM) by carrying out a series of positron annihilation studies on clean intimate metal-semiconductor junctions; to conduct PFAM investigations on the following semiconductor substrates: GaAs, GaP, GaN and SiC possibly using semi-insulating forms or material; to use the most advanced diagnostic positron spectroscopy techniques, including Coincidence Doppler Broadening Spectroscopy (CDBS) to study any adverse positron trapping at the metal-semiconductor interface.

Project Title:	Developing Variable Energy Positron Annihilation Lifetime Spectroscopy
Investigator(s):	Beling CD
Department:	Physics
Source(s) of Funding:	Merit Award for RGC CERG Funded Projects
Start Date:	01/2005

Abstract:

N/A

List of Research Outputs

Beling C.D., Ling F.C.C., Cheung C.K., Naik P.S., Zhang J. and Fung S.H.Y., Positron beam studies of transients in semiconductors, Applied Surface Science. Amsterdam, Elsevier B.V., 2006, 252: 3172-3182.

Chen X., Huang Y., Ling F.C.C., Fung S.H.Y. and Beling C.D., 4-11 Electrical characterization of defects at the gallium nitride based homo- and hetero-junctions, 第十五屆全國半導體物理年會: 論文摘要集, Sichuan, Sichuan University, 2005, 41.

Chen X., Ling F.C.C., Fung S.H.Y., Beling C.D., Mei Y.F., Fu R.K.Y., Siu G.G. and Chu P.K., Current transport studies of ZnO/p-Si heterostructures grown by plasma immersion ion implantation and deposition, Applied Physics Letters. New York, American Institute of Physics, 2006, 88: 132104:1-3.

Cheung C.K., Naik P.S., Beling C.D., Fung S.H.Y. and Weng H.M., Performance of a slow positron beam using a hybrid lens design, Applied Surface Science. Amsterdam, Elsevier B.V., 2006, 252: 3132-3137.

Kwan P.Y.R., Cheung C.K., Beling C.D. and Fung S.H.Y., Preliminary studies on a variable energy positron annihilation lifetime spectroscopy system, Applied Surface Science. Amsterdam, Elsevier B.V., 2006, 252: 3138-3142.

Li S., Zhang J., Beling C.D., Wang K., Wang R., Gong M. and Sarkar C.K., Large lattice relaxation deep levels in neutron-irradiated GaN, Journal of Applied Physics. New York, American Institute of Physics, 2005, 98: 093517: 1-6.

Wang R., Djurisic A., Beling C.D. and Fung S.H.Y., Indium Tin Oxide (ITO) thin films: Fabrication, properties, post-deposition treatments and applications, In: Elliot T.B., Trends in Semiconductor Research. Nova Science Publishers, Inc., 2005, Chapter 6: 137-174.

Wang R., Xu S.J., Fung S.H.Y., Beling C.D., Wang K., Li S., Wei Z., Zhou T., Zhang J., Huang Y. and Gong M., Micro-Raman and photoluminescence studies of neutron-irradiated gallium nitride epilayers, Applied Physics Letters. New York, American Institute of Physics, 2005, 87: 031906:1-3.

Wang R., Xu S.J., Li S., Fung S.H.Y., Beling C.D., Wang K., Wei Z., Zhou T., Zhang J., Gong M. and Pang G.K.H., Raman scattering and X-ray diffraction study of neutron irradiated GaN epilayers, Proceeding of 2004 Conference on Optoelectronic and Microelectronic Materials and Devices, 8-10 December 2004, Australia. IEEE, 2005, 141-143.

Wang R., Beling C.D., Fung S.H.Y., Djurisic A., Kwong C.Y. and Li S., The effect of thermal annealing on the properties of indium tin oxide thin films, Proceeding of 2004 Conference on Optoelectronic and Microelectronic Materials and Devices, 8-10 December 2004, Australia. IEEE, 2005, 57-60.

Zhang J., Zhou T., Cheung C.K., Beling C.D., Fung S.H.Y. and Ng M.K., Deconvolution of 2D coincident Doppler broadening spectroscopy using the Richardson-Lucy algorithm, Nuclear Instruments and Methods in Physics Research A. Amsterdam, Elsevier B.V., 2006, 560: 552-557.

Zhong Z.Q., Wu D.X., Gong M., Wang O., Shi S., Xu S.J., Chen X., Ling F.C.C., Fung S.H.Y., Beling C.D., Brauer G., Anwand W. and Skorupa W., Primary photoluminescence in as-neutron (electron) –irradiated n-type 6H-SiC, Journal of Applied Physics. New York, American Institute of Physics, 2006, 99: 093511: 1-3.

Researcher : Cai X

List of Research Outputs

Cai X., Djurisic A., Xie M.H., Chiu C.S. and Gwo S., Growth mechanism of stacked-cone and smooth-surface GaN nanowires, Applied Physics Letters. New York, American Institute of Physics, 2005, 87: 183103: 1-3.

Cai X., Djurisic A. and Xie M.H., Growth of SiO_x nanowire bunches cocatalyzed with Ga and Ni, Journal of Applied Physics. New York, American Institute of Physics, 2005, 98: 074313:1-5.

Cai X., Growth, doping and nanostructures of gallium nitride. Hong Kong, The University of Hong Kong, 2005, 1-121.

Cai X., Cheng K.W., Oey C.C., Djurisic A., Chan W.K., Xie M.H. and Chui P.C., Porous metallic films fabricated by self-assembly of gold nanoparticles, Thin Solid Films. Amsterdam, Elsevier B.V., 2005, 491: 66-70.

Cai X., Leung Y.H., Cheung K.Y., Tam K.H., Djurisic A., Xie M.H., Chen H.Y. and Gwo S., Straight and helical InGaN core-shell nanowires with a high In core content, Nanotechnology. Bristol, IOP Publishing Limited, 2006, 17: 2330-2333.

Researcher : Chau HF

Project Title:	Cryptanalysis of Certain Quantum Cryptographic Applications
Investigator(s):	Chau HF
Department:	Physics
Source(s) of Funding:	Competitive Earmarked Research Grants (CERG)
Start Date:	10/2004

Abstract:

To study the interplay and tradeoff between efficiency, error tolerable rate and resources requirements in various quantum crytographic applications. I begin the study by first focusing on quantum key distribution. The outcome is essential in devising new quantum cryptographic protocols that suit specific applications.

Project Title:	Cryptanalysis of Certain Quantum Cryptographic Applications
Investigator(s):	Chau HF
Department:	Physics
Source(s) of Funding:	Merit Award for RGC CERG Funded Projects
Start Date:	01/2005

Abstract:

N/A

List of Research Outputs

Chau H.F., Insecurity of imperfect quantum bit seal, Physics Letters A. Amsterdam, Elsevier B.V., 2006, 354: 31-34.

Chau H.F., Chow F.K., Ho K.H. and Man W.C., Multiple choice minority game with different publicly known histories, New Journal of Physics. Bristol, IOP Publishing Limited, 2005, 7: 206:1-12.

Chau H.F., Reply to "Comment on 'Quantum convolutional error-correcting codes' ", Physical Review A. New York, The American Physical Society, 2005, 72: 026302:1.

Man W.C. and Chau H.F., Incorporating inertia into multiagent systems, Physical Review E. New York, The American Physical Society, 2006, 73: 036106:1-9.

Man W.C., Ho K.H., Chow F.K. and Chau H.F., The relevance of memory in minority game, Progress of Theoretical Physics Supplement. Japan, 2006, 162: 190-196.

Researcher : Chen X

List of Research Outputs

Chen X., Huang Y., Ling F.C.C., Fung S.H.Y. and Beling C.D., 4-11 Electrical characterization of defects at the gallium nitride based homo- and hetero-junctions, 第十五屆全國半導體物理年會: 論文摘要集, Sichuan, Sichuan University, 2005, 41.

Chen X., Ling F.C.C., Fung S.H.Y., Beling C.D., Mei Y.F., Fu R.K.Y., Siu G.G. and Chu P.K., Current transport studies of ZnO/p-Si heterostructures grown by plasma immersion ion implantation and deposition, Applied Physics Letters. New York, American Institute of Physics, 2006, 88: 132104:1-3.

Ling F.C.C., Chen X., Brauer G., Anwand W., Skorupa W., Wang H. and Weng H.M., Deep-level defects in n-type 6H silicon carbide induced by He implantation, Journal of Applied Physics. New York, American Institute of Physics, 2005, 98: 043508:1-6.

Ling F.C.C., Chen X., Gong M., Yang C.L., Ge W.K. and Wang J.N., Electron energy dependence on inducing the photoluminescence lines of 6H-SiC by electron irradiation, Physica B. Amsterdam, Elsevier B.V., 2006, 376-377: 374-377.

Zhong Z.Q., Wu D.X., Gong M., Wang O., Shi S., Xu S.J., Chen X., Ling F.C.C., Fung S.H.Y., Beling C.D., Brauer G., Anwand W. and Skorupa W., Primary photoluminescence in as-neutron (electron) –irradiated n-type 6H-SiC, Journal of Applied Physics. New York, American Institute of Physics, 2006, 99: 093511: 1-3.

Researcher : Chen Y

Project Title:	Pairing symmetry, competing orders and local physics in electron-doped high temperature superconductors
Investigator(s):	Chen Y, Wang ZD, Zhang FC
Department:	Physics
Source(s) of Funding:	Seed Funding Programme for Basic Research
Start Date:	02/2004
Completion Date:	09/2006

Abstract:

To investigate the superconductivity and other competing orders, more specially, spin density wave; to investigate the existence of two possible types of superconducting order parameters at different pockets of the Fermi surface; to investigate the local electronic structure around impurities or vortex cores, both local density of states and nuclear magnetic resonance relaxation rate will be calculated.

Project Title:	Theoretical Studies of Electronic States in Electron-doped High Temperature Superconductors
Investigator(s):	Chen Y, Wang ZD, Zhang FC
Department:	Physics
Source(s) of Funding:	Competitive Earmarked Research Grants (CERG)
Start Date:	09/2004

Abstract:

The electronic structure of electron-doped cuprates has attracted significant interest both experimentally and theoretically in recent years. Substantial asymmetry exists between the less studied electron-doped and intensively studied hole-doped cuprates. In order to elucidate the mechanism of high temperature superconductivity, it is fundamentally important to clarify the origin of the similarity and the differences between the electron-doped and the hole-doped cuprates.

Project Title:	Theoretical Studies of Electronic States in Electron-doped High Temperature Superconductors
Investigator(s):	Chen Y
Department:	Physics
Source(s) of Funding:	Merit Award for RGC CERG Funded Projects
Start Date:	01/2005

Abstract:

N/A

Project Title:	Mixed States in High Temperature Superconductors: Scenario of Competing Orders
Investigator(s):	Chen Y, Zhang FC, Wang ZD
Department:	Physics
Source(s) of Funding:	Seed Funding Programme for Basic Research
Start Date:	04/2005

Abstract:

The electronic structure of mixed states in high temperature superconductors (HTS) has attracted significant interest both experimentally and theoretically for past many years. Many important physical phenomena arise from competing orders, including pseudogap, superconductor-insulator transition, which cannot be explained within a conventional theory. It is well established that the competition between d-wave superconductivity (DSC) and antiferromagnetic (AF) orders plays an essential role in determining the vortex state of HTS. In view of the widely used competing order scenario of the HTS in the mixed state and impurity state, together with the fact that the competing order effect has not been considered in some existing theories relevant to mixed state. In this project, we will focus on the field dependence of the vortex structure, Nernst effect and anomalous Hall effect, which are different from conventional superconductors. We believe the competition between AF and DSC may not only provide a coherent way to understand the vortex structure but also gain new insights on the above-mentioned specific features of the experimental measurements. In terms of the results to be obtained, we attempt to understand profoundly some existing experimental results as well as to suggest new experiments to test our predictions.

Project Title:	Mixed States in High Temperature Superconductors: Scenario of Competing Orders
Investigator(s):	Chen Y
Department:	Physics
Source(s) of Funding:	Incentive Award for RGC CERG Fundable But Not Funded Projects
Start Date:	07/2005
Completion Date:	06/2006

Abstract:

N/A

List of Research Outputs

Chen Y., Wang Z.D. and Zhang F.C., Exploring Quantum Phase Transitions with a Novel Sublattice Entanglement Scenario , The 4th International Conference on Condensed Matter Theory and Materials Computation (July 11 – 16, 2005, Chengdu, China) . 2005.

Chen Y., Wang Z.D. and Zhang F.C., Exploring quantum phase transitions with a sublattice entanglement scenario, Physical Review B. New York, The American Physical Society, 2006, 73: 224414:1-5.

Chen Y., Zanardi P., Wang Z.D. and Zhang F.C., Sublattice entanglement and quantum phase transitions in antiferromagnetic spin chains, New Journal of Physics. IOP Publishing Ltd, 2006, 8: 1-9.

Gan J.Y., Chen Y., Su Z.B. and Zhang F.C., Gossamer superconductivity in layered organic compounds K-(BEDT-TTF)₂X, Progress of Theoretical Physics Supplement. Japan, 2005, 15-27.

Wang Q.H., Wang Z.D., Chen Y. and Zhang F.C., Unrestricted renormalized mean field theory of strongly correlated electron systems, Physical Review B (Brief Reports). New York, The American Physical Society, 2006, 73: 092507: 1-4.

Researcher : Chen Z

List of Research Outputs

Chen Z. and Shen S.Q., Non-exponential relaxation and the distribution of the second-order transverse anisotropic parameters in Mn₁₂, European Physical Journal B. EDP Sciences, 2005, 48: 405-408.

Researcher : Cheng KS

Project Title:	Properties of strange stars and their observational appearance
Investigator(s):	Cheng KS, Usov V.V., Suen W.M.
Department:	Physics
Source(s) of Funding:	Competitive Earmarked Research Grants (CERG)
Start Date:	07/2003

Abstract:

To study the emissivity and transport properties of electronmagnetic waves in semi-degenerate and inhomogeneous electron gas of the strange star atmosphere; the thermal emissivity of hot quark surface in electron-positron pairs; to calculate electron-positron pairs more precisely, hopefully with accuracy of ~10% or even higher; to study electromagnetic waves produced by passing the quarks and also the propagation of electromagnetic waves through the electron atmosphere, which is semi-degenerate and inhomogeneous; to study the strange star cooling by taking into account the processes mentioned in (1)-(3). And other processes such as formation of color-flavor locked phase inside the star, chiral symmetry requirement in the boundary, will be included in the cooling calculations; to study the observational consequences of producing strange stars by accretion including how much gravitational and phase transition energy will be released through gravitational and electromagnetic waves. The possible connection between this process and [gamma]-ray bursts will be studied as well.

Project Title:	Properties of strange stars and their observational appearance
Investigator(s):	Cheng KS, Usov V.V., Suen W.M.
Department:	Physics
Source(s) of Funding:	Merit Award for RGC CERG Funded Projects
Start Date:	07/2003

Abstract:

N/A

Project Title:	Time variation of fundamental physical constants in theories with extra-dimensions
Investigator(s):	Cheng KS
Department:	Physics
Source(s) of Funding:	Small Project Funding
Start Date:	11/2003

Abstract:

To study in a systematically manner the possibility that the time variability of some fundamental physical constants (the elementary electric charge e, the speed of light c and the gravitational constant G) is due to the presence of the extra dimensions. More specifically, to consider the fundamental constants as some physical fields in a five-dimensional space-time and to examine the effects of such a hypothesis on the four-dimensional space-time.

Project Title:	Transient Gamma-ray Sources: Gamma-ray Bursts and Other Related Astrophysical Phenomena
Investigator(s):	Cheng KS, Huang Y.F., Lu T., Dai Z.G.
Department:	Physics
Source(s) of Funding:	Competitive Earmarked Research Grants (CERG)
Start Date:	07/2004

Abstract:

To study (1) the evolution of the postburst fireball and their afterglows under different cases, e.g. effects of dense media, non-uniformity of media, geometry of jets (isotropic or highly collimated?) etc. We will compare the observed light curves and the time dependent multi-wave band spectra of the afterglows with model results. This information should provide very important clues to understand the origin of GRBs. (2) the inverse-Comption scattering in the internal shock can generate TeV photons, which are expected to form electron/positron pairs by collisions with inter-galactic infrared photons. Subsequent collisions between TeV pairs and cosmic microwave photons can cause delayed GeV-GRBs. The delay time scales and the spectra of delayed GeV-GRBs should be detectable for GLAST and provide vital information for the inter-galactic infrared photons as well as inter-galactic magnetic field. (3) some ideas, which we learn from GRBs, can be used to explain other transient gamma-ray phenomena, e.g. Anomalous X-Ray pulsars, Soft Gamma Repeaters and Microquasars, which exhibit some similar activities liek GBRs. For example, they all have jet-like features during the outburst states (flares) and their subsequent radiation processes could be explained in terms of internal/external shock mechanism, which are the mechanisms used to explain the radiation processes of GRBs.

Project Title:	Neutron star- Neutron star collisions
Investigator(s):	Cheng KS, Suen W.M.
Department:	Physics
Source(s) of Funding:	Seed Funding Programme for Basic Research
Start Date:	01/2005
Completion Date:	06/2006

Abstract:

The objective of this program is to develop numerical relativity and apply it to astrophysics that involves strong and dynamical gravitational fields requiring the full Einstein theory for its understanding. In particular we want to apply it to neutron star merger system.

Project Title:	Transient Gamma-ray Sources: Gamma-ray Bursts and Other Related Astrophysical Phenomena
Investigator(s):	Cheng KS
Department:	Physics
Source(s) of Funding:	Merit Award for RGC CERG Funded Projects
Start Date:	01/2005

Abstract:

N/A

Project Title:	High Energy Radiation from Pulsar and Pulsar Wind Nebula
Investigator(s):	Cheng KS
Department:	Physics
Source(s) of Funding:	Merit Award for RGC CERG Funded Projects
Start Date:	07/2005

Abstract:

N/A

Project Title:	High Energy Radiation from Pulsar and Pulsar Wind Nebula
Investigator(s):	Cheng KS, Taam RE, Zhang L
Department:	Physics
Source(s) of Funding:	Competitive Earmarked Research Grants (CERG)
Start Date:	07/2005

Abstract:

There are three basic objectives of this project: (1) To study the magnetospheric radiation of a pulsar (2) To study the radiation resulting from the interaction between a pulsar wind and its surrounding medium (3) To study the relation between some unidentified high energy radiation point sources and pulsars

Project Title:	High Energy Emission from the Galactic Black Hole
Investigator(s):	Cheng KS
Department:	Physics
Source(s) of Funding:	Seed Funding Programme for Basic Research
Start Date:	02/2006

Abstract:

Non-thermal high energy radiation emission within multi-pc scale from the center region of our galaxy has been observed. In particular very intense TeV photons are observed by various VHE experimental groups in the world. We believe that these high energy photons, especially TeV photon emission, are the result of a transient activity of the massive black hole SgrA*, which resides at the Galactic center. About hundred thousands of years ago, the black hole may have experienced in active phase by capturing a main sequence star and forming an accretion disk, temporarily behaving like an active galactic nuclear resemble to the activities observed in quasars. A powerful jet, which contains plenty of high speed protons, was launched during the process. These runaway protons interact with the dense ambient medium, producing high energy radiation emission through the decay of neutral pions. We believe that the total energy deposited in this way is large enough to account for observations. We will compare the model results with the observed data.

List of Research Outputs

Cheng K.S., Emission mechanisms and broad band spectra of pulsars, 6th NATO ASI series: The Electromagnetic Spectrum of Neutron Stars. Springer, 2005, 173-184.

Cheng K.S. and Romero G.E., In: Cheng K.S., Romero G.E., Multiwavelength approach to unidentified gamma-ray sources. Springer, 2005, 1-438.

Cheng K.S., Taam R.E. and Wang W., Pulsar wind nebulae and the nonthermal x-ray emission of millisecond pulsars, The Astrophysical Journal. The American Astronomical Society, 2006, 641: 427-437.

Harko T.C. and Cheng K.S., Electron-positron pair production in the electrosphere of quark stars, Astrophysical Journal. The American Astronomical Society, 2006, 643: 318-331.

Harko T.C. and Cheng K.S., Galactic metric, dark radiation, dark pressure, and gravitational lensing in brane world models, The Astrophysical Journal. The American Astronomical Society, 2006, 636: 8-20.

Huang Y., Cheng K.S. and Gao T.T., Modeling the optical afterglow of GRB 030329, The Astrophysical Journal. The American Astronomical Society, 2006, 637: 873-879.

Huang Y.F., Lu T. and Cheng K.S., GRB afterglows: Deep Newtonian phase and its application, IL Nuovo Cimento C. Bologna, Società Italiana di Fisica, 2005, 28: 415-418.

Lin L.M., Cheng K.S., Chu M.C. and Suen W.M., Gravitational waves from phase-transition-induced collapse of neutron stars, The Astrophysical Journal. The American Astronomical Society, 2006, 639: 382-396.

Lu Y., Cheng K.S. and Huang Y., Capture of a red giant by the black hole Sagittarius A* as a possible origin for the TeV gamma rays from the galactic center, The Astrophysical Journal. The American Astronomical Society, 2006, 641: 288-292.

Tam P.H., Cheng K.S., Wang X.Y., Huang Y.F. and Pun J.C.S., Gamma-ray burst afterglows with cylindrical jet geometry, IL Nuovo Cimento C. Bologna, Società Italiana di Fisica, 2005, 28: 447-450.

Wang W., Pun J.C.S. and Cheng K.S., Could electron-positron annihilation lines in the Galactic center result from pulsar winds?, Astronomy & Astrophysics. EDP Sciences, 2006, 446: 943-948.

Wang X., Cheng K.S., Dai Z.G. and Lu T., High-energy component of GRB 941017 revisited and the reverse-shock synchrotron self-Compton emission, Astronomy & Astrophysics. ESO, 2005, 439: 957-961.

Researcher : Cheng KYR

List of Research Outputs

Cheng K.Y.R., Nuclear emergency preparedness model based on Daya Bay nuclear power stations for educational purposes. Hong Kong, The University of Hong Kong, 2005, 1-135.

Cheng K.Y.R. and Leung J.K.C., Nuclear emergency preparedness model in Hong Kong, The 2nd International Exergy, Energy and Environment Symposium (IEEES2). Greece, KOS, 2005.

Researcher : Cheung CH

List of Research Outputs

Cheung C.H., Djurisic A., Kwong C.Y., Chan J., Rakic A.D., Tam H.L., Cheah K.W., Liu Z., Chan W.K. and Chui P.C., Dependence of the emission from tris (8-hydroxyquinoline) aluminum based microcavity on device thickness and the emission layer position, Thin Solid Films. Amsterdam, Elsevier B.V., 2005, 489: 235-244.

Cheung C.H., Fabrication and characterization of microcavity organic light emitting diodes. Hong Kong, The University of Hong Kong, 2005, 1-103.

Lui H.F., Fong W.K., Surya C., Cheung C.H. and Djurisic A., Fabrication and characterization of indium-tin-oxide/GaN visible-blind UV detectors, Physica Status Solidi C. Weinheim, WILEY-VCH Verlag GmbH & Co., 2006, 3: 2295-2298.

Oey C.C., Djurisic A., Kwong C.Y., Cheung C.H., Chan W.K., Nunzi J.M. and Chui P.C., Nanocomposite hole injection layer for organic device applications, Thin Solid Films. Amsterdam, Elsevier B.V., 2005, 492: 253-258.

Researcher : Cheung CK

List of Research Outputs

Beling C.D., Ling F.C.C., Cheung C.K., Naik P.S., Zhang J. and Fung S.H.Y., Positron beam studies of transients in semiconductors, Applied Surface Science. Amsterdam, Elsevier B.V., 2006, 252: 3172-3182.

Cheung C.K., Naik P.S., Beling C.D., Fung S.H.Y. and Weng H.M., Performance of a slow positron beam using a hybrid lens design, Applied Surface Science. Amsterdam, Elsevier B.V., 2006, 252: 3132-3137.

Kwan P.Y.R., Cheung C.K., Beling C.D. and Fung S.H.Y., Preliminary studies on a variable energy positron annihilation lifetime spectroscopy system, Applied Surface Science. Amsterdam, Elsevier B.V., 2006, 252: 3138-3142.

Zhang J., Zhou T., Cheung C.K., Beling C.D., Fung S.H.Y. and Ng M.K., Deconvolution of 2D coincident Doppler broadening spectroscopy using the Richardson-Lucy algorithm, Nuclear Instruments and Methods in Physics Research A. Amsterdam, Elsevier B.V., 2006, 560: 552-557.

Researcher : Cheung KY

List of Research Outputs

Cai X., Leung Y.H., Cheung K.Y., Tam K.H., Djurisic A., Xie M.H., Chen H.Y. and Gwo S., Straight and helical InGaN core-shell nanowires with a high In core content, Nanotechnology. Bristol, IOP Publishing Limited, 2006, 17: 2330-2333.

Researcher : Ching PP

List of Research Outputs

Ching P.P., Constraining neutrino oscillation parameters q₁₂ and Dm ² ₁₂ with a short baseline reactor anti-neutrino experiment. Hong Kong, The University of Hong Kong, 2005, 1-59.

Researcher : Chow FK

List of Research Outputs

Chau H.F., Chow F.K., Ho K.H. and Man W.C., Multiple choice minority game with different publicly known histories, New Journal of Physics. Bristol, IOP Publishing Limited, 2005, 7: 206:1-12.

Man W.C., Ho K.H., Chow F.K. and Chau H.F., The relevance of memory in minority game, Progress of Theoretical Physics Supplement. Japan, 2006, 162: 190-196.

Researcher : Dai D

List of Research Outputs

Dai D., Xu S.J., Shi S., Xie M.H. and Che C.M., Efficient multiphoton-absorption-induced luminescence in single-crystalline ZnO at room temperature, Optics Letters. Washington, Optical Society of America, 2005, 30: 3377-3379.

Li Q., Xu S.J., Dai D. and Che C.M., Two-photon excited photoluminescence in InGaN multi-quantum-wells structures, Proceeding of 2004 Conference on Optoelectronic and Microelectronic Materials and Devices, 8-10 December 2004, Australia. IEEE, 2005, 153-155.

Researcher : Dai S

List of Research Outputs

Duan P., Chen Z.H., Dai S., Liu L.F. and Gao J., Electrical transport and magnetic properties of perovskite-type electron-doped La-Pr-Mn-O epitaxial films, Journal of Magnetism and Magnetic Materials. Amsterdam, Elsevier B.V., 2006, 301: 521-526.

Researcher : Dai X

Project Title:	The studies on the dynamical mean field theory and its application in the first principle calculation of the strongly correlated materials
Investigator(s):	Dai X
Department:	Physics
Source(s) of Funding:	Merit Award for RGC CERG Funded Projects
Start Date:	09/2005

Abstract:

N/A

Project Title:	The studies on the dynamical mean field theory and its application in the first principle calculation of the strongly correlated materials
Investigator(s):	Dai X, Zhang FC, Wang ZD
Department:	Physics
Source(s) of Funding:	Competitive Earmarked Research Grants (CERG)
Start Date:	09/2005

Abstract:

1) To develop several fast impurity solvers which can be used in the LDA+DMFT calculation for the Mott insulators, where the effective quantum impurity model is close to the atomic limit. 2) Apply the LDA+DMFT method to do the first principle calculation for the typical anti-ferromagnetic materials, such as $MnF_2$ and $MnO$. 3) To develop a impurity solver in the strong local interaction but with non integer particle filling.

Project Title:	The optical response of the semiconductor quatum well structure carrying non-zero spin current
Investigator(s):	Dai X
Department:	Physics
Source(s) of Funding:	Seed Funding Programme for Basic Research
Start Date:	01/2006

Abstract:

Recently the spintronics, whose main task is to study the transport and manipulation of the spin degree of freedom in solids, become a very hot field of the condensed matter physics. One of the big problem of the spintronics is how to generate and detect spin current, which can transport spin signals from one place to another. Unlike the charge current, which is very easy to detect, the pure spin current is very hard to detect. About two years ago, the study of spin Hall effect (SHE), in which an electric field induces a transverse spin current, has recently evolved into a subject of intense research. The intrinsic SHE was proposed by Murakami et al. in p-type semiconductor of a Luttinger Hamiltonian and by Sinova in 2-dimensional (2D) electron systems with Rashba spin-orbit coupling. Their works have generated a lot of theoretical activities. Current theoretical understanding is that the intrinsic SHE does not survive in the diffusive transport in the thermodynamic limit for the 2D Rashba electron system in the absence of strong magnetic fields but the effect appears to be robust in the 2D hole gases p-doped bulk semiconductors and the modified Rashba coupling case. The earlier theoretical work on the extrinsic SHE is associated with the impurity scattering, such as the skew scattering and the side jump processes. On the experimental side, there have been two groups reporting the observation of SHE. Kato et.al. used Kerr rotation microscopy to detect and image electrically induced electron-spin polarization near the edge of a n-type semiconductor channel. The effect was suggested to be extrinsic based on the weak dependence on crystal orientation for the strained samples. Very recently, Sih et al. have reported spatial imaging of the SHE and current-induced polarization in 2D electron gases. Wunderlich et al. observed the SHE in 2D hole system with spin-orbit coupling, and interpreted the effect to be intrinsic. Therefore it will be very important if we can propose a new way to measure the spin current by out theoretical study. Since both of the two experimental on the possible spin Hall effects are done by the optical measurement. The Kerr effect was used in Kato's experiment and photo luminescence was used in Wunderlich's experiment. On the other hand, the optical properties of the semiconductors with strong spin-orbital coupling itself is a very interesting problem which has been studies extensively in the past twenty years, because it shed light on how to manipulate spin by the optical way. Based on the above research background, we plan to carry out the theoretical studies on the optical properties of the semiconductor quantum wells with the strong spin-orbital coupling. In the study, we will focus on two very fundamental problems. One is that is there any new physical phenomena in the optical absorption or emission which is induced by the spin-orbital coupling? Since we know that the spin Hall effect in the 2 dimensional electron (hole) gas is induced by the non-trivial Berry phase in the momentum space, one would ask how does this kind of Berry phase manifest itself in the optical absorption or emission? The second interesting problem that we are currently working with is that what is the optical response for a quantum well sample which is carrying a non-zero spin current? Does the spin current feature manifest itself in the optical response? If so, can we develop a new method to measure the spin current? In this proposal, we plan to study the optical response of the semiconductor quantum well with strong spin-orbital coupling. Using the kp method which has been developed for 40 years, we are going to study the absorption of the circlely polarized (CP) light by the quantum well structure. As discovered already by many groups, the absorption of the CP light will not generate any net charge current when the light is applied perpendicular to the xy-plane. Here we are going to calculate the change of the absorption rate of the CP light induced by a external static electric field. Because of the spin Hall effect, the electron (hole) spin which is originally lying within the plane will tilt out of the plane, which will affect the absorption rate of the CP light. We will study if such an effect will result in a non-zero charge current along the transverse direction within the plane. If so, this charge current is purely caused by the external electric field and is totally a new effect in semiconductor physics. Another very important issue is that is it possible to measure the spin current itself rather than the spin accumulation at the edge by the optical method? This problem can also be answered by our study. We expect that the presence of the spin current will affect the cross section of the optical absorption or emission processes. And thus provide a new optical method to measure the spin current directly. Since up to now, there is no method which can measure the spin current directly, our theoretical research will be extremely significant in the area of the spintronics.

List of Research Outputs

Dai X., Fang Z., Yao Y.G. and Zhang F.C., Resonant intrinsic spin Hall effect in p-type GaAs quantum well structure, Physical Review Letters. New York, The American Physical Society, 2006, 96: 086802: 1-4.

Dai X., Haule K. and Kotliar G., Strong-coupling solver for the quantum impurity model, Physical Review B. New York, The American Physical Society, 2005, 72: 045111:1-6.

Dai X., Ma M. and Zhang F.C., Theory for supersolid ⁴He: Vacancy condensation facilitated by a low-energy bound state of a vacancy and an interstitial, Physical Review B (Brief Reports). New York, The American Physical Society, 2005, 72: 132504: 1-4.

He H.T., Yang C.L., Ge W.K., Wang J.N., Dai X. and Wang Y.Q., Resistivity minima and Kondo effect in ferromagnetic GaMnAs films, Applied Physics Letters. New York, American Institute of Physics, 2005, 87: 162506: 1-3.

Li J., Dai X., Shen S.Q. and Zhang F.C., Transverse electric current induced by optically injected spin current in a cross-shaped InGaAs/InAlAs system, Applied Physics Letters. New York, American Institute of Physics, 2006, 88: 162105: 1-3.

Researcher : Djurisic A

Project Title:	Organic/inorganic nanocomposites for photovoltaic cells and organic light emitting diodes
Investigator(s):	Djurisic A, Chan WK, Sahraoui B., Nunzi J.M.
Department:	Physics
Source(s) of Funding:	France/Hong Kong Joint Research Scheme - Travel Grants
Start Date:	01/2004
Completion Date:	12/2005

Abstract:

To study the optical and charge transport properties in the organic/inorganic nanocomposites; to fabricate and characterize photovoltaic cells with improved performance based on organic/inorganic nanocomposites; to fabricate composite layers with improved charge transport and apply them to organic light emitting diodes (OLEDs).

Project Title:	Structural, electrical, and optical properties of organic/inorganic nanocomposites for optoelectronic applications
Investigator(s):	Djurisic A, Chan WK
Department:	Physics
Source(s) of Funding:	Competitive Earmarked Research Grants (CERG)
Start Date:	09/2004

Abstract:

To study : (1) the fabrication and/or surface modifications of inorganic nanostructures; (2) the fabrication of nanocomposite films containing one or more types of nanostructures; (3) the study of structural, electrical, and optical properties of nanocomposite films; (3) the application of nanocomposite films to organic light emitting diodes and organic solar cells.

Project Title:	Fabrication and Characterization of Organic Micro- and Nanostructures for Optoelectronic Device Applications
Investigator(s):	Djurisic A, Chan WK
Department:	Physics
Source(s) of Funding:	Seed Funding Programme for Basic Research
Start Date:	01/2005
Completion Date:	02/2006

Abstract:

Objectives: Fabrication and characterization of organic nanostructures Exploring the application of organic nanostructures in organic optoelectronic devices We propose to fabricate and characterize organic nanostructures for a variety of materials which are of interest for applications in organic optoelectronic devices. Both materails of interest for organic light emitting diodes and organic solar cells will be considered. These nanostructures are of interest both from practical applications and fundamental science points of view. Since the majority of the work on nanomaterials is focused on inorganic nanostructures, growth mechanisms and relationship between the fabrication conditions, structure, and properties of organic nanostructures are generally unknown. On the other hand, it is expected that the use of nanostructured materials instead of conventional thin films will improve the performance of organic optoelectonic devices. Therefore, we propose to study the organic nanostructures fabricated under different conditions, optimize the fabrication conditions to yield morphologies of interest for optoelectronic devices, and investigate the application of most promising structures in organic light emitting diodes and organic solar cells.

Project Title:	Structural, electrical, and optical properties of organic/inorganic nanocomposites for optoelectronic applications
Investigator(s):	Djurisic A
Department:	Physics
Source(s) of Funding:	Merit Award for RGC CERG Funded Projects
Start Date:	01/2005

Abstract:

N/A

Project Title:	Synthesis and properties of oxide nanostructures
Investigator(s):	Djurisic A
Department:	Physics
Source(s) of Funding:	Incentive Award for RGC CERG Fundable But Not Funded Projects
Start Date:	07/2005
Completion Date:	06/2005

Abstract:

N/A

Project Title:	Dye- and polymer sensitized solar cells based on novel nanostructured semiconductor layers
Investigator(s):	Djurisic A
Department:	Physics
Source(s) of Funding:	Seed Funding Programme for Basic Research
Start Date:	01/2006
Completion Date:	12/2006

Abstract:

In order to maintain a sustainable environment, there is a high demand to produce inexpensive renewable energy sources. Therefore, the development of low production cost solar cells is of particular interest. Organic materials have an important advantage of enabling fabrication of devices on large are and flexible substrates, using inexpensive solution processing techniques. Among different types of organic solar cells, dye-sensitized cells typically have the highest power conversion efficiency, which is ~10%. A dye-sensitized solar cell typically consists of a porous TiO2 layer infiltrated with dye sensitizer molecules. To study the factors limiting the efficiency of these cells, as well as to try to improve the charge transport and reduce recombination of generated carriers, different nanostructured semiconductors (ZnO, SnO2) in addition to TiO2 are intensively investigated. In addition, polymer sensitized solar cells are being studied in order to achieve good performance solid state devices without liquid electrolyte. In this project, different nanostructured metal oxides will be prepared and their application to the dye- and polymer-sensitized solar cells will be investigated. Objectives: o Fabrication of dye-sensitized and polymer-sensitized solar cells based on novel metal oxide nanostructured layers o Study of the influence of nanostructured layer morphology on the solar cell performance o Optimizing the architecture of the solar cells based on novel nanostructured layers to achieve improved device performance.

Project Title:	Optical properties of ZnO nanostructures
Investigator(s):	Djurisic A, Nunzi J.M., Chan WK
Department:	Physics
Source(s) of Funding:	France/Hong Kong Joint Research Scheme - Travel Grants
Start Date:	01/2006

Abstract:

1) Fabrication and charaterization of the optical properties of ZnO nanostructures; 2) Investigation of the effect of surface functionalization on the optical properties

List of Research Outputs

Cai X., Djurisic A., Xie M.H., Chiu C.S. and Gwo S., Growth mechanism of stacked-cone and smooth-surface GaN nanowires, Applied Physics Letters. New York, American Institute of Physics, 2005, 87: 183103: 1-3.

Cai X., Djurisic A. and Xie M.H., Growth of SiO_x nanowire bunches cocatalyzed with Ga and Ni, Journal of Applied Physics. New York, American Institute of Physics, 2005, 98: 074313:1-5.

Cai X., Cheng K.W., Oey C.C., Djurisic A., Chan W.K., Xie M.H. and Chui P.C., Porous metallic films fabricated by self-assembly of gold nanoparticles, Thin Solid Films. Amsterdam, Elsevier B.V., 2005, 491: 66-70.

Cai X., Leung Y.H., Cheung K.Y., Tam K.H., Djurisic A., Xie M.H., Chen H.Y. and Gwo S., Straight and helical InGaN core-shell nanowires with a high In core content, Nanotechnology. Bristol, IOP Publishing Limited, 2006, 17: 2330-2333.

Chan J., Rakic A.D., Kwong C.Y., Liu Z., Djurisic A., Majewski M.L., Chan W.K. and Chui P.C., Device optimization of tris-aluminum (Alq₃) based bilayer organic light emitting diode structures, Smart Materials and Structures. Bristol, IOP Publishing Limited, 2006, 15: S92-S98.

Chan W.K., Hui C.S., Man K.K.Y., Cheng K.W., Wong H.L., Zhu N. and Djurisic A., Synthesis and photosensitizing properties of conjugated polymers that contain chlorotricarbonyl bis(phenylimino)acenaphthene rhenium(I) complexes, Coordination Chemistry Reviews. Amsterdam, Elsevier B.V., 2005, 249: 1351-1359.

Chan W.K., Man K.K.Y. and Djurisic A., Use of organometallic polyelectrolytes for multilayer thin film deposition, American Chemical Society 230th National Meeting, Washington DC, August 28-September 1, 2005. . 2005.

Cheung C.H., Djurisic A., Kwong C.Y., Chan J., Rakic A.D., Tam H.L., Cheah K.W., Liu Z., Chan W.K. and Chui P.C., Dependence of the emission from tris (8-hydroxyquinoline) aluminum based microcavity on device thickness and the emission layer position, Thin Solid Films. Amsterdam, Elsevier B.V., 2005, 489: 235-244.

Djurisic A., Wang H., Chan W.K. and Xie M.H., Characterization of block copolymers using scanning probe microscopy, Journal of Scanning Probe Microscopy. American Scientific Publishers, 2006, 1: 21-31.

Djurisic A., Leung Y.H., Tam K.H., Ding L., Ge W.K., Chen H.Y. and Gwo S., Green, yellow, and orange defect emission from ZnO nanostructures: Influence of excitation wavelength, Applied Physics Letters. New York, American Institute of Physics, 2006, 88: 103107: 1-3.

Djurisic A., Kwok W.M., Chan W.K., Phillips D.L., Leung Y.H., Xie M.H., Chen H.Y., Wu C.L. and Gwo S., Optical properties of highly faceted ZnO rods, Journal of Applied Physics. New York, American Institute of Physics, 2006, 99: 033517: 1-6.

Djurisic A., Kwok W.M., Leung Y.H., Phillips D.L. and Chan W.K., Stimulated emission in ZnO nanostructures: A time-resolved study, Journal of Physical Chemistry B. American Chemical Society, 2005, 109: 19228-19233.

Djurisic A., Kwok W.M., Leung Y.H., Chan W.K., Phillips D.L., Lin M.S. and Gwo S., Ultrafast spectroscopy of stimulated emission in single ZnO tetrapod nanowires, Nanotechnology. Bristol, IOP Publishing Limited, 2006, 17: 244-249.

Kwok W.M., Djurisic A., Leung Y.H., Chan W.K., Phillips D.L., Chen H.Y., Wu C.L., Gwo S. and Xie M.H., Study of excitonic emission in highly faceted ZnO rods, Chemical Physics Letters. Amsterdam, Elsevier B.V., 2005, 412: 141-144.

Kwok W.M., Djurisic A., Leung Y.H., Chan W.K. and Phillips D.L., Time-resolved photoluminescence from ZnO nanostructures, Applied Physics Letters. New York, American Institute of Physics, 2005, 87: 223111: 1-3.

Kwok W.M., Djurisic A., Leung Y.H., Chan W.K. and Phillips D.L., Time-resolved photoluminescence study of the stimulated emission in ZnO nanoneedles, Applied Physics Letters. New York, American Institute of Physics, 2005, 87: 093108:1-3.

Kwok W.M., Leung Y.H., Phillips D.L., Chan W.K. and Djurisic A., Ultrafast time - and wavelength - resolved photoluminescence study of stimulated emission on selected ZnO nanostructures , International Chemical Congress of Pacific Basin Societies (PACIFICHEM 2005), Houolulu, Hawaii, U.S.A., Dec 15-20,. 2005.

Kwok W.M., Djurisic A., Leung Y.H., Chan W.K., Lin M.S., Gwo S. and Phillips D.L., Ultrafast time - and wavelength - resolved photoluminescence study of stimulated emission on selected ZnO nanostructures , The 4th Asian Conference on Ultrafast Phenomena, The Hong Kong University of Science and Technology, Hong Kong, January 8-11, 2006.

Leung C.Y., Djurisic A., Leung Y.H., Ding L., Yang C.L. and Ge W.K., Influence of the carrier gas on the luminescence of ZnO tetrapod nanowires, Journal of Crystal Growth. Amsterdam, Elsevier B.V., 2006, 290: 131-136.

Leung Y.H., Djurisic A. and Xie M.H., Non-catalytic synthesis of ZnO nanocolumns with different cross-sections, Journal of Crystal Growth. Amsterdam, Elsevier B.V., 2005, 284: 80-85.

Leung Y.H., Tam K.H., Djurisic A., Xie M.H., Chan W.K., Lu D. and Ge W.K., ZnO nanoshells: synthesis, structure, and optical properties, Journal of Crystal Growth. Amsterdam, Elsevier B.V., 2005, 283: 134-140.

Li D., Leung Y.H., Djurisic A., Liu Z., Xie M.H., Gao J. and Chan W.K., CuO nanostructures prepared by a chemical method, Journal of Crystal Growth. Amsterdam, Elsevier B.V., 2005, 282: 105-111.

Lui H.F., Fong W.K., Surya C., Cheung C.H. and Djurisic A., Fabrication and characterization of indium-tin-oxide/GaN visible-blind UV detectors, Physica Status Solidi C. Weinheim, WILEY-VCH Verlag GmbH & Co., 2006, 3: 2295-2298.

Man K.K.Y., Wong H.L., Chan W.K., Djurisic A., Beach E. and Rozeveld S., Use of a ruthenium-containing conjugated polymer as a photosensitizer in photovoltaic devices fabricated by a layer-by-layer deposition process, Langmuir. American Chemical Society, 2006, 22: 3368-3375.

Oey C.C., Djurisic A., Kwong C.Y., Cheung C.H., Chan W.K., Nunzi J.M. and Chui P.C., Nanocomposite hole injection layer for organic device applications, Thin Solid Films. Amsterdam, Elsevier B.V., 2005, 492: 253-258.

Oey C.C., Djurisic A., Wang H., Man K.K.Y., Chan W.K., Xie M.H., Leung Y.H., Pandey A., Nunzi J.M. and Chui P.C., Polymer-TiO₂ solar cells: TiO₂ interconnected network for improved cell performance, Nanotechnology. Bristol, IOP Publishing Limited, 2006, 17: 706-713.

Wang H., Djurisic A., Chan W.K. and Xie M.H., Factors affecting phase and height contrast of diblock copolymer PS-b-PEO thin films in dynamic force mode atomic force microscopy, Applied Surface Science. Amsterdam, Elsevier B.V., 2005, 252: 1092-1100.

Wang H., Djurisic A., Xie M.H., Chan W.K. and Kutsay O., Morphology evolution of an asymmetric diblock copolymer P(S-b-MMA) as a function of film thickness and annealing time, International Journal of Nanoscience. Singapore, World Scientific, 2005, 4: 737-743.

Wang H., Djurisic A., Xie M.H., Chan W.K. and Kutsay O., Perpendicular domains in poly(styrene-b-methyl methacrylate) block copolymer films on preferential surfaces, Thin Solid Films. Amsterdam, Elsevier B.V., 2005, 488: 329-336.

Wang H., Oey C.C., Djurisic A., Xie M.H., Leung Y.H., Man K.K.Y., Chan W.K., Pandey A., Nunzi J.M. and Chui P.C., Titania bicontinuous network structures for solar cell applications, Applied Physics Letters. New York, American Institute of Physics, 2005, 87: 023507:1-3.

Wang R., Djurisic A., Beling C.D. and Fung S.H.Y., Indium Tin Oxide (ITO) thin films: Fabrication, properties, post-deposition treatments and applications, In: Elliot T.B., Trends in Semiconductor Research. Nova Science Publishers, Inc., 2005, Chapter 6: 137-174.

Wang R., Beling C.D., Fung S.H.Y., Djurisic A., Kwong C.Y. and Li S., The effect of thermal annealing on the properties of indium tin oxide thin films, Proceeding of 2004 Conference on Optoelectronic and Microelectronic Materials and Devices, 8-10 December 2004, Australia. IEEE, 2005, 57-60.

Researcher : Duan R

List of Research Outputs

Wei Z., Xu S.J., Duan R., Li Q., Wang J., Zeng Y.P. and Liu H.C., Thermal quenching of luminescence from buried and surface InGaAs self-assembled quantum dots with high sheet density, Journal of Applied Physics. New York, American Institute of Physics, 2005, 98: 084305: 1-4.

Researcher : Fu E

List of Research Outputs

Fu E., Study of epitaxial thin films of YBa₂Cu₃O_7-d on silicon with different buffer layers. Hong Kong, The University of Hong Kong, 2005, 1-113.

Researcher : Fung PCW

Project Title:	Development of a novel natural antioxidant with strong anti-aging and protective properties for skin
Investigator(s):	Fung PCW, Shen J
Department:	Medicine
Source(s) of Funding:	Seed Funding Programme for Applied Research
Start Date:	07/2002

Abstract:

To develop a novel antioxidants from herbal products which can scavenge superoxide, hydroxyl and lipid peroxide free radicals in skin.

Project Title:	Roles of plasma membrane cholesterol homeostasis in regulating neuronal oxidative damage of ischemic stroke
Investigator(s):	Fung PCW, Shen J
Department:	Medicine
Source(s) of Funding:	Small Project Funding
Start Date:	11/2003

Abstract:

To understand the roles of plasma membrane cholesterol homeostasis in protecting neuronal cells from oxidative damage during ischemic stroke.

Project Title:	High level brain activity studies and applications
Investigator(s):	Fung PCW, Chang C, Gao S.K., Gao X.R., Zhang Z.G., Yang F.S., Poon P.W.F., Chan FHY
Department:	Medicine
Source(s) of Funding:	NSFC/RGC Joint Research Scheme
Start Date:	01/2004

Abstract:

To better understand and utilize the functioning of the brain.

List of Research Outputs

Researcher : Fung S

Project Title:	Study of Particle Irradiation Induced Defects in Gallium Nitride
Investigator(s):	Fung SHY
Department:	Physics
Source(s) of Funding:	Competitive Earmarked Research Grants (CERG)
Start Date:	09/2004
Completion Date:	09/2006

Abstract:

To systematically study the particle irradiation induced defects in GaN. Irradiation with electrons, neutrons, and protons is known to damage semiconductor materials by causing atomic displacement and/or ionization. The type and size of defects created depend on the energy, mass, charge, and fluency of the irradiating particles. Thus various defects such as mono-vacancy, divacancy, interstitial and antisite with different generation rates in samples irradiated with different particles may be studied; to compare the properties of defects created by the three different irradiation particles mentioned above.

Project Title:	Study of Particle Irradiation Induced Defects in Gallium Nitride
Investigator(s):	Fung SHY
Department:	Physics
Source(s) of Funding:	Merit Award for RGC CERG Funded Projects
Start Date:	01/2005

Abstract:

N/A

List of Research Outputs

Researcher : Fung SHY

Project Title:	Study of Particle Irradiation Induced Defects in Gallium Nitride
Investigator(s):	Fung SHY
Department:	Physics
Source(s) of Funding:	Competitive Earmarked Research Grants (CERG)
Start Date:	09/2004
Completion Date:	09/2006

Abstract:

Project Title:	Study of Particle Irradiation Induced Defects in Gallium Nitride
Investigator(s):	Fung SHY
Department:	Physics
Source(s) of Funding:	Merit Award for RGC CERG Funded Projects
Start Date:	01/2005

Abstract:

N/A

List of Research Outputs

Beling C.D., Ling F.C.C., Cheung C.K., Naik P.S., Zhang J. and Fung S.H.Y., Positron beam studies of transients in semiconductors, Applied Surface Science. Amsterdam, Elsevier B.V., 2006, 252: 3172-3182.

Chen X., Huang Y., Ling F.C.C., Fung S.H.Y. and Beling C.D., 4-11 Electrical characterization of defects at the gallium nitride based homo- and hetero-junctions, 第十五屆全國半導體物理年會: 論文摘要集, Sichuan, Sichuan University, 2005, 41.

Chen X., Ling F.C.C., Fung S.H.Y., Beling C.D., Mei Y.F., Fu R.K.Y., Siu G.G. and Chu P.K., Current transport studies of ZnO/p-Si heterostructures grown by plasma immersion ion implantation and deposition, Applied Physics Letters. New York, American Institute of Physics, 2006, 88: 132104:1-3.

Cheung C.K., Naik P.S., Beling C.D., Fung S.H.Y. and Weng H.M., Performance of a slow positron beam using a hybrid lens design, Applied Surface Science. Amsterdam, Elsevier B.V., 2006, 252: 3132-3137.

Ding L., Chen T.P., Liu Y., Ng C.Y. and Fung S.H.Y., An approach to optical-property profiling of a planar-waveguide structure of Si nanocrystals embedded in SiO₂, Nanotechnology. Bristol, IOP Publishing Limited, 2005, 16: 2657-2660.

Ding L., Chen T.P., Liu Y., Ng C.Y. and Fung S.H.Y., Optical properties of silicon nanocrystals embedded in a SiO₂ matrix, Physical Review B. New York, The American Physical Society, 2005, 72: 125419:1-7.

Ding L., Chen T.P., Liu Y., Ng C.Y., Liu Y.C. and Fung S.H.Y., Thermal annealing effect on the band gap and dielectric functions of silicon nanocrystals embedded in SiO₂ matrix, Applied Physics Letters. New York, American Institute of Physics, 2005, 87: 121903:1-3.

Kwan P.Y.R., Cheung C.K., Beling C.D. and Fung S.H.Y., Preliminary studies on a variable energy positron annihilation lifetime spectroscopy system, Applied Surface Science. Amsterdam, Elsevier B.V., 2006, 252: 3138-3142.

Liu Y., Chen T.P., Ng C.Y., Ding L., Tse M.S., Fung S.H.Y. and Tseng A.A., Influence of Si-nanocrystal distribution in the oxide on the charging behavior of MOS structures, IEEE Transactions on Electron Devices. IEEE, 2006, 53: 914-917.

Liu Y., Chen T.P., Zhao P., Zhang S., Fung S.H.Y. and Fu Y.Q., Memory effect of Al-rich AlN films synthesized with rf magnetron sputtering, Applied Physics Letters. New York, American Institute of Physics, 2005, 87: 033112:1-3.

Ng C.Y., Chen T.P., Ding L., Yang M., Wong J.I., Zhao P., Yang X.H., Liu K.Y., Tse M.S., Trigg A.D. and Fung S.H.Y., Influence of Si nanocrystal distributed in the gate oxide on the MOS capacitance, IEEE Transactions on Electron Devices. IEEE, 2006, 53: 730-736.

Ng C.Y., Chen T.P., Ding L. and Fung S.H.Y., Memory characteristics of MOSFETs with densely stacked silicon nanocrystal layers in the gate oxide synthesized by low-energy ion beam, IEEE Electron Device Letters. IEEE, 2006, 27: 231-233.

Ng C.Y., Chen T.P., Ding L., Chen Q., Liu Y., Zhao P., Tseng A.A. and Fung S.H.Y., Si ion-induced instability in flatband voltage of Si⁺-implanted gate oxides, IEEE Transactions on Electron Devices. IEEE, 2006, 53: 1280-1282.

Ng C.Y., Chen T.P., Ding L., Liu Y., Tse M.S., Fung S.H.Y. and Dong Z.L., Static dielectric constant of isolated silicon nanocrystals embedded in a SiO₂ thin film, Applied Physics Letters. New York, American Institute of Physics, 2006, 88: 063103: 1-3.

Wang R., Djurisic A., Beling C.D. and Fung S.H.Y., Indium Tin Oxide (ITO) thin films: Fabrication, properties, post-deposition treatments and applications, In: Elliot T.B., Trends in Semiconductor Research. Nova Science Publishers, Inc., 2005, Chapter 6: 137-174.

Wang R., Xu S.J., Fung S.H.Y., Beling C.D., Wang K., Li S., Wei Z., Zhou T., Zhang J., Huang Y. and Gong M., Micro-Raman and photoluminescence studies of neutron-irradiated gallium nitride epilayers, Applied Physics Letters. New York, American Institute of Physics, 2005, 87: 031906:1-3.

Wang R., Xu S.J., Li S., Fung S.H.Y., Beling C.D., Wang K., Wei Z., Zhou T., Zhang J., Gong M. and Pang G.K.H., Raman scattering and X-ray diffraction study of neutron irradiated GaN epilayers, Proceeding of 2004 Conference on Optoelectronic and Microelectronic Materials and Devices, 8-10 December 2004, Australia. IEEE, 2005, 141-143.

Wang R., Beling C.D., Fung S.H.Y., Djurisic A., Kwong C.Y. and Li S., The effect of thermal annealing on the properties of indium tin oxide thin films, Proceeding of 2004 Conference on Optoelectronic and Microelectronic Materials and Devices, 8-10 December 2004, Australia. IEEE, 2005, 57-60.

Zhang J., Zhou T., Cheung C.K., Beling C.D., Fung S.H.Y. and Ng M.K., Deconvolution of 2D coincident Doppler broadening spectroscopy using the Richardson-Lucy algorithm, Nuclear Instruments and Methods in Physics Research A. Amsterdam, Elsevier B.V., 2006, 560: 552-557.

Zhong Z.Q., Wu D.X., Gong M., Wang O., Shi S., Xu S.J., Chen X., Ling F.C.C., Fung S.H.Y., Beling C.D., Brauer G., Anwand W. and Skorupa W., Primary photoluminescence in as-neutron (electron) –irradiated n-type 6H-SiC, Journal of Applied Physics. New York, American Institute of Physics, 2006, 99: 093511: 1-3.

Researcher : Gao J

Project Title:	Preparation of epitaxial YBa₂Cu₃O_y thin films on silicon with a double buffer of Eu₂CuO₄/YSZ
Investigator(s):	Gao J
Department:	Physics
Source(s) of Funding:	Competitive Earmarked Research Grants (CERG)
Start Date:	10/2002

Abstract:

The project proposes to reveal the feasibility of applying a double buffer EuCuO(ECO)/YSZ to improve the growth of YBCO on Si. The synthesis process, resultant structural properties and their relation to superconductivity of YBCO films will be investigated. In addition, their crystalline and superconductivity, as well as the interfaces will be systematically studied.

Project Title:	Current induced deduction on the peak resistance of perovskite transition metal oxides
Investigator(s):	Gao J
Department:	Physics
Source(s) of Funding:	Small Project Funding
Start Date:	11/2003
Completion Date:	03/2007

Abstract:

To study the influence of a transport current in the peak resistance of perovskite transition metal oxides.

Project Title:	Opto-electric response and light excitation in heteroepitaxial thin films of R1-xAxMnO3 perovskite oxides
Investigator(s):	Gao J
Department:	Physics
Source(s) of Funding:	Seed Funding Programme for Basic Research
Start Date:	01/2005
Completion Date:	12/2006

Abstract:

The electronic states in perovskite oxides R1-xAxMnO3, which are not completely understood currently, play the dominant role in determining the material properties. The motivation of the research lies in the opto-electronic response in heteroepitaxial thin films of these compounds. The main objective is to reveal the nature of giant electroresistance (ER) and to get a better understanding of the mechanism that account for the peculiar nonlinear electronic transport. Our efforts will be focused at the electron-phonon interaction and the effects induced by optical excitation in these materials, as well as the modulation process of a light/field on the coexistence of multiphases in different systems. In particular, the following pertinent scientific and technical issues will be addressed: • Growth and structural characterization of heteroepitaxial films of various perovskite manganites. • Electronic states and optical characterization in these heteroepitaxial structures. • The opto-electronic responses and giant ER effects under an optical or field excitation. Effort will be also made to explore the feasibility for device applications, though it is not the main objective. This part of study explore how the applied field affects the properties of these material in hoping to shed light on the physical mechanisms, which are difficult to understand using conventional research scheme. Interaction between a material and external excitation is always a hot subject in physics society. Our recent study has shown that a current with a high density can induce a giant ER in the ABO3 thin films. With the incorporation of optical excitation into the experiment, free carriers can be excited in the materials and, likely, the MI transition will be influenced. Our research will aim at the dynamical process of the way that electrons are excited and how the photon-generated electrons interact with Mn ions. Since the magnetic properties of R1-xAxMnO3 is closely related to holes, optical excitation can serve as a unique laboratory in which many of the material properties can be studied.

Project Title:	Normal and abnormal giant electroresistance induced by currents in epitaxial thin films of mixed-valent manganite oxides
Investigator(s):	Gao J
Department:	Physics
Source(s) of Funding:	Merit Award for RGC CERG Funded Projects
Start Date:	01/2005

Abstract:

N/A

Project Title:	Normal and abnormal giant electroresistance induced by currents in epitaxial thin films of mixed-valent manganite oxides
Investigator(s):	Gao J
Department:	Physics
Source(s) of Funding:	Competitive Earmarked Research Grants (CERG)
Start Date:	01/2005

Abstract:

To systematically investigate the current induced giant ER effect in wide range of epitaxial thin films of mixed-valent manganite oxides; to study the nature of the novel metastable state introduced subsequently by applying a large current, i.e. the abnormal ER effect; try to understand the physical mechanism behind these experimental observations.

Project Title:	Magnetically tunable heterojunctions constructed with manganite perovskites
Investigator(s):	Gao J
Department:	Physics
Source(s) of Funding:	Merit Award for RGC CERG Funded Projects
Start Date:	01/2006

Abstract:

N/A

Project Title:	Magnetically tunable heterojunctions constructed with manganite perovskites
Investigator(s):	Gao J
Department:	Physics
Source(s) of Funding:	Competitive Earmarked Research Grants (CERG)
Start Date:	01/2006

Abstract:

The main objective of this project is to explore the feasibility for developing functional p-n heterojunctions from manganite perovskites, which could be magnetically tunable. As the influence of the giant MR and ER on behavior of these heterojunctions has not been well understood, our study would be very likely to emerge interesting results and may exhibit unexpected new properties or phenomena

List of Research Outputs

Bai Z., Wang Z.H., Li P.J., Qiu L., Zhang H. and Gao J., Evidence of d-wave pairing in MTG-YBa₂Cu_2.99Li_0.01O_x crystals determined from the low-temperature specific heat, Superconductor Science and Technology. Bristol, IOP Publishing Limited, 2006, 19: 503-507.

Duan P., Chen Z.H., Dai S., Liu L.F. and Gao J., Electrical transport and magnetic properties of perovskite-type electron-doped La-Pr-Mn-O epitaxial films, Journal of Magnetism and Magnetic Materials. Amsterdam, Elsevier B.V., 2006, 301: 521-526.

Gao J. and Hu F., Effect of magnetic fields on the abnormal electroresistance behavior in epitaxial thin films of La_0.8Ca_0.2MnO₃, Materials Science and Engineering B. Amsterdam, Elsevier B.V., 2006, 126: 250-253.

Gao J., Hu F. and Yao H., Impact of electric currents on the insulator-metal phase transition in epitaxial thin films of La_1-xA_xMnO₃ (A = Sr, Ca, and Ba), Applied Surface Science. Amsterdam, Elsevier B.V., 2006, 252: 5521-5524.

Gao J. and Yang J., Improvement of epitaxy and crystallinity in YBa₂Cu₃O_y thin films grown on silicon with double buffer of ECO/YSZ, Transactions of Nonferrous Metals Society of China. Science Press, 2006, 16: s245-s248.

Gao J., Sun J. and Yang J., Transport and interface properties in ramp-type Josephson junctions with a graded Y_1-xPr_xBa₂Cu₃O_y barrier, Physica C. Amsterdam, Elsevier B.V., 2006, 436: 86-92.

Hao J.H. and Gao J., A novel hydrate-based thin-film phosphor: low-temperature growth process and properties, Applied Physics A: Materials Science & Processing. Berlin, Springer-Verlag, 2005, 81: 1277-1280.

Hao J.H. and Gao J., Application of optical and luminescent techniques to the characterization of oxide thin films, Applied Surface Science. Amsterdam, Elsevier B.V., 2006, 252: 5590-5593.

Hao J.H., Gao J., Wang Z. and Yu D.P., Interface structure and phase of epitaxial SrTiO₃ (110) thin films grown directly on silicon, Applied Physics Letters. New York, American Institute of Physics, 2005, 87: 131908:1-3.

Hao J.H., Gao J. and Wong H.K., SrTiO₃(110) thin films grown directly on different oriented silicon substrates, Applied Physics A. Berlin, Springer-Verlag, 2005, 81: 1233-1236.

Hu F., Gao J. and Wu X.S., Controllable colossal electroresistance in La_0.8Ca_0.2MnO₃ epitaxial thin films, Physical Review B. New York, The American Physical Society, 2005, 72: 064428:1-5.

Hu F. and Gao J., Current-induced asymmetric transport in La_0.8Ca_0.2MnO₃ epitaxial thin films, Applied Physics Letters. New York, American Institute of Physics, 2005, 87: 152504:1-3.

Hu F., Gao J. and Wang Z.H., Electroresistance and magnetoresistance in La_0.9Ba_0.1MnO₃ thin films, Materials Science and Engineering B. Amsterdam, Elsevier B.V., 2006, 126: 102-105.

Hu F. and Gao J., Investigations on electroresistance effect in epitaxial manganite films using field effect configurations, Applied Physics Letters. New York, American Institute of Physics, 2006, 88: 132502: 1-3.

Hu F. and Gao J., The influence of static-electric field on the transport properties in La_0.7Ca_0.3MnO₃ epitaxial thin films, Journal of Applied Physics. New York, American Institute of Physics, 2006, 99: 08Q314: 1-3.

Li D., Leung Y.H., Djurisic A., Liu Z., Xie M.H., Gao J. and Chan W.K., CuO nanostructures prepared by a chemical method, Journal of Crystal Growth. Amsterdam, Elsevier B.V., 2005, 282: 105-111.

Li P.J., Wang Z.H., Zhang H., Nie Y., Bai Z., Qiu L., Ding S.Y. and Gao J., Effective pinning energy in Li-doped MTG-YBa₂Cu₃O_y crystals, Superconductor Science and Technology. Bristol, IOP Publishing Limited, 2006, 19: 392-396.

Li P.J., Wang Z.H., Hu A.M., Bai Z., Qiu L. and Gao J., The collective flux pinning force in (Sm_0.5Eu_0.5)Ba₂Cu₃O_7-d superconductors, Superconductor Science and Technology. Bristol, IOP Publishing Limited, 2006, 19: 825-829.

Lian G.J., Wang X., Xiong G.C. and Gao J., Variation of the transition temperature in strained epitaxial Y_1-xPr_xBa₂Cu₃O₇ ultrathin layers, Physical Review B. New York, The American Physical Society, 2005, 72: 024503:1-5.

Qian B., Xing J.H., Wu X., Jiang S.S. and Gao J., Magnetoresistance in La- and Ca-doped YBa₂Cu₃O_7-d, Journal of Applied Physics. New York, American Institute of Physics, 2006, 99: 08M504: 1-3.

Tan W.S., Cai H.L., Liu J.S., Wu X.S., Jiang S.S., Wu Z.H., Jia Q.J. and Gao J., Characterization of surface and interface structure of YBa₂Cu₃O_7-d-based trilayer with La_0.67Ca_0.33MnO₃ spacer, Journal of Applied Physics. New York, American Institute of Physics, 2006, 99: 08M509: 1-3.

Tan W.S., Jia Q.J. and Gao J., Possible abnormal mechanism for lattice strain relaxation in La_0.7Ca_0.3MnO₃ thin film, International Journal of Modern Physics B. Singapore, World Scientific, 2005, 19: 2415-2420.

Yao H., Hu F. and Gao J., Strain effect and current-induced electroresistance in epitaxial thin films of La_0.9Sr_0.1MnO₃, Thin Solid Films. Amsterdam, Elsevier B.V., 2006, 495: 165-168.

Zhang Y.M., Wu X.S., Jiang S.S., Tan W.S. and Gao J., Thickness dependence of morphology in La_2/3Ca_1/3MnO₃ thin films, International Journal of Modern Physics B. World Scientific Pub., 2005, 19: 2409-2414.

Researcher : Hao J

Project Title:	Dielectric properties in novel perovskite oxide thin films
Investigator(s):	Hao JH
Department:	Physics
Source(s) of Funding:	Seed Funding Programme for Basic Research
Start Date:	12/2004

Abstract:

Objective of the research proposal: Design and synthesis of novel functional oxides with unusual and promising dielectric properties. Investigation of processing effects on the structural and dielectric properties of thin films. Searching and understanding of some possible new phenomena in novel perovskite oxide thin films. The key issue is to investigate how the preparation parameters of perovskite oxide thin film affect their dielectric properties. The key problem is interfacial effects between novel perovskite oxides and various substrates. In the proposed investigation, the growth of epitaxial thin film with full control will be carried out. Various structural, dielectric and optical characterizations will be employed.

Project Title:	Laser molecular beam epitaxy growth and characterization of SrTiO3 thin films for tunable YBa2Cu3Oy applications
Investigator(s):	Hao JH, Gao J
Department:	Physics
Source(s) of Funding:	Competitive Earmarked Research Grants (CERG)
Start Date:	12/2004

Abstract:

To investigate SrTiO₃ thin films that exhibit enhanced dielectric properties suitable for tunable YBa₂Cu₃O_y (YBCO) applications with the specific aims of: (1) well-controlled epitaxial growth of STO thin films by laser molecular beam epitaxy (MBE); (2) establishment of the correlations between the deposition parameters of STO thin films, their structural characteristics, and dielectric properties. Realization of the fundamental mechanisms of dielectric properties in STO thin films; (3) evaluation of the feasibility of laser MBE grown YBCO/STO multilayers for tunable applications.

Project Title:	Laser molecular beam epitaxy growth and characterization of SrTiO3 thin films for tunable YBa2Cu3Oy applications
Investigator(s):	Hao JH
Department:	Physics
Source(s) of Funding:	Merit Award for RGC CERG Funded Projects
Start Date:	01/2005

Abstract:

N/A

Project Title:	Substrate and buffer layer engineering for epitaxial perovskite titanate thin films
Investigator(s):	Hao JH
Department:	Physics
Source(s) of Funding:	Merit Award for RGC CERG Funded Projects
Start Date:	01/2006

Abstract:

N/A

Project Title:	Substrate and buffer layer engineering for epitaxial perovskite titanate thin films
Investigator(s):	Hao JH, Gao J
Department:	Physics
Source(s) of Funding:	Competitive Earmarked Research Grants (CERG)
Start Date:	01/2006

Abstract:

Project objectives: To investigate heteroepitaxial structures of perovskite titanates like strontium titanate thin films grown on various substrates and buffer layers with the specific aims of: 1) Design and development of suitable sets of buffer layers/substrates used to improve physical properties of perovskite titanate thin films. 2) Determining interface and strain effects on the structural and dielectric properties of various controlled heterostructures. 3.Identifying and understanding of some new phenomena such as the possible occurrence of strain-induced FE in perovskite titanate films.

List of Research Outputs

Researcher : Hao JH

Project Title:	Dielectric properties in novel perovskite oxide thin films
Investigator(s):	Hao JH
Department:	Physics
Source(s) of Funding:	Seed Funding Programme for Basic Research
Start Date:	12/2004

Abstract:

Project Title:	Laser molecular beam epitaxy growth and characterization of SrTiO3 thin films for tunable YBa2Cu3Oy applications
Investigator(s):	Hao JH, Gao J
Department:	Physics
Source(s) of Funding:	Competitive Earmarked Research Grants (CERG)
Start Date:	12/2004

Abstract:

Project Title:	Laser molecular beam epitaxy growth and characterization of SrTiO3 thin films for tunable YBa2Cu3Oy applications
Investigator(s):	Hao JH
Department:	Physics
Source(s) of Funding:	Merit Award for RGC CERG Funded Projects
Start Date:	01/2005

Abstract:

N/A

Project Title:	Substrate and buffer layer engineering for epitaxial perovskite titanate thin films
Investigator(s):	Hao JH
Department:	Physics
Source(s) of Funding:	Merit Award for RGC CERG Funded Projects
Start Date:	01/2006

Abstract:

N/A

Project Title:	Substrate and buffer layer engineering for epitaxial perovskite titanate thin films
Investigator(s):	Hao JH, Gao J
Department:	Physics
Source(s) of Funding:	Competitive Earmarked Research Grants (CERG)
Start Date:	01/2006

Abstract:

List of Research Outputs

Hao J.H. and Gao J., A novel hydrate-based thin-film phosphor: low-temperature growth process and properties, Applied Physics A: Materials Science & Processing. Berlin, Springer-Verlag, 2005, 81: 1277-1280.

Hao J.H. and Gao J., Application of optical and luminescent techniques to the characterization of oxide thin films, Applied Surface Science. Amsterdam, Elsevier B.V., 2006, 252: 5590-5593.

Hao J.H., Dielectric and structural properties of SrTiO3 thin films grown by laser molecular beam epitaxy, 11th National Conference on Dielectric Physics, materials and applications. 2005.

Hao J.H., Gao J., Wang Z. and Yu D.P., Interface structure and phase of epitaxial SrTiO₃ (110) thin films grown directly on silicon, Applied Physics Letters. New York, American Institute of Physics, 2005, 87: 131908:1-3.

Hao J.H., Low-temperature synthesis and cathodoluminescence properties of borate-based thin films, 14th International Conference on Luminescence (ICL' 05), Beijing, China. 2005.

Hao J.H., Metal oxides for microelectronic and optoelectronic applications, College of Microelctronics and Solid State Electronics, University of Electronic Science and Technology, Chengdu, China. 2005.

Hao J.H., Properties and applications of metal oxides, Superconductivity R&D Center, Southwest Jiaotong University, Chengdu, China. 2005.

Hao J.H., Gao J. and Wong H.K., SrTiO₃(110) thin films grown directly on different oriented silicon substrates, Applied Physics A. Berlin, Springer-Verlag, 2005, 81: 1233-1236.

Lou Z.D. and Hao J.H., Cathodoluminescent characteristics of green-emitting ZnAl2O4: Mn thin film phosphors, 14th International Conference on Luminescence (ICL' 05), Beijing, China. 2005.

Researcher : Harko TC

Project Title:	Observational tests of the brane world cosmological models
Investigator(s):	Harko TC
Department:	Physics
Source(s) of Funding:	Seed Funding Programme for Basic Research
Start Date:	01/2005
Completion Date:	12/2005

Abstract:

The idea that our four-dimensional Universe might be a higher dimensional space-time, had been proposed and studied, from both mathematical and physical points of view, for a long time. Recently, due to the proposal by Randall and Sundrum [1-2] that our four-dimensional space-time is a three-brane, embedded in a five-dimensional space-time (the bulk), the idea of the embedding of our Universe in a higher dimensional space had attracted again a considerable interest. According to the brane-world scenario, the physical fields (electromagnetic, Yang-Mills etc.) in our four-dimensional Universe are confined to the three brane. These fields are assumed to arise as fluctuations of branes in string theories. Only gravity can freely propagate in both the brane and bulk space-times, with the gravitational self-couplings not significantly modified. Due to the correction terms coming from the extra dimensions, significant deviations from the Einstein theory occur in brane world models at very high energies [3-4]. Gravity is largely modified at the electro-weak scale of 1 TeV. The cosmological implications of the brane world theories have been extensively investigated in the physical literature [5-7]. In the present project our main objective is to study the modifications due to extra-dimensional or non-Riemannian effects on some particular astrophysical processes and to propose some observational tests which could provide evidence for the existence of extra-dimensions or non-Riemannian geometries and to discriminate between different models. Some specific objectives for this project are as follows: (1) The study of the vacuum static solutions of the gravitational field equations with the extra-dimensional effects included. The modification of the classical Schwarzschild geometry of general relativity, due to the extra-dimensional (bulk) effects leads to the possibility of testing the model at the solar system or at a galactic scale. This can be done by using either the classical tests of general relativity (perihelion precession, light deflection, gravitational redshift) for the solar system or by considering the galactic dynamics. (2) High energy photons propagating at cosmological distances interact differently with the gravitational field in the presence of multi-dimensional or non-riemannian geometries. Thus for these photons a supplementary time delay or a gravitational rotation of the polarization plan can be induced. In particular, gamma ray bursts are very good candidates for the study of these effects. We plan to study the transfer equation of radiation in space-times with more general geometries than the Riemannian one and in arbitrary dimensions and to obtain from the photon propagation data some constraints on the extra-dimensions. (3) Observations show that the rotational velocities increase near the center of the galaxy and then remain nearly constant at a value of around 200 km/s [8]. This behavior of the galactic rotation curves is explained by postulating the existence of some dark (invisible) matter, distributed in a spherical halo around the galaxies. We shall study the possibility that the behavior of the galactic rotation curves could be explained in the brane world model, due to the presence of the supplementary terms in the gravitational field equations. This could lead to the possibility of observationally testing gravitational theories with more than four dimensions by using the galactic rotation curves. A systematic comparison between the predictions of the brane-world model and observational results will be considered in detail. References [1] L. Randall and R. Sundrum, Phys. Rev. Lett. {\bf 83}, 3370 (1999). [2] L. Randall and R. Sundrum, Phys. Rev. Lett {\bf 83}, 4690 (1999). [3] C. M. Chen, T. Harko, W. F. Kao and M. K. Mak, Nucl. Phys. {\bf B636}, 159 (2002). [4] C. M. Chen, T. Harko and M. K. Mak, Phys. Rev. {\bf D64}, 044013 (2001). [5] R. Maartens, Phys. Rev. {\bf D62}, 084023 (2000). [6] A. Campos and C. F. Sopuerta, Phys. Rev. {\bf D63}, 104012 (2001). [7] C. M. Chen, T. Harko and M. K. Mak, Phys. Rev. {\bf D64}, 124017 (2001). [8] J. Binney and S. Tremaine, Galactic dynamics, Princeton, Princeton University Press, (1987)

Project Title:	Radiation from the electrosphere of bare strange stars
Investigator(s):	Harko TC
Department:	Physics
Source(s) of Funding:	Incentive Award for RGC CERG Fundable But Not Funded Projects
Start Date:	07/2005
Completion Date:	06/2006

Abstract:

N/A

Project Title:	Radiation processes in the electrosphere of bare strange stars
Investigator(s):	Harko TC
Department:	Physics
Source(s) of Funding:	Seed Funding Programme for Basic Research
Start Date:	01/2006
Completion Date:	12/2006

Abstract:

Strange stars, consisting of deconfined quark matter, are particularly difficult to be differentiated observationally from neutron stars. Both quark and neutron stars have very similar masses and radii. Their detection is further complicated by the very low photon emissivity of the quark matter, which is six orders of magnitude below the black body energy flux. A bare strange star has a very sharp boundary surface, which prevents energy loss through emitting thermal X-rays from the stellar surface due to the extremely high plasma frequency. The main objective of this project is to study some properties of bare strange stars, offering some unique features which could help in the observational identification of this type of compact objects. Some specific objectives for this project are as follows: (1) A hot bare strange star may be a powerful source of electron-positron pairs, which are created in the electrosphere and can flow away from the star. We shall consider in detail the effects of the finite extension and rapid decrease of the electric field on the electron-positron pair creation and how they affect the luminosity of the star. We shall consider the pair creation process in strong variable electric fields in terms of an effective barrier penetration problem. To study the process of tunneling through the forbidden region we shall use wave function techniques and a WKB type approximation of the penetration factor. (2) The increases in the electron density and electric field intensity lead to a strong modification of the electron-electron bremsstrahlung radiation properties of the electron gas. Due to the extremely high plasma frequency radiation emission from the inner parts of the electrosphere is suppressed. However, electron-electron bremsstrahlung radiation emission can take place in the outer parts of the electron layer and thus the electrosphere is a source of low frequency X-ray radiation, which may be observable by a distant observer. Because of its specific and unique spectrum, this radiation could become the main observational signature for a bare strange star. We will study in detail the emissivity and spectrum of the radiation emitted by the outer layers of the electron gas, by considering in detail the effects of the degeneracy of the gas. (3) In order to have a better understanding of the radiation emission from the electrosphere we shall consider in detail the radiation transport inside the electrosphere. The most important physical process taking place in the electrosphere is the scattering of photons by the free electrons. Depending on this scattering the emission of the electrosphere could have a blackbody spectrum at the star surface temperature or the re-absorption of the emitted radiation could be unimportant. We shall study the radiation transport in the electrosphere by using both analytical and numerical approaches. We shall consider the radiation transport equation with both relativistic and non-relativistic sources of opacity. References [1] E. Witten, Phys. Rev. D 30, 272 (1984) [2] C. Alcock, E. Farhi and A.. Olinto, Astrophys. J. 310, 261 (1986) [3] Ch. Kettner, F. Weber, M. K. Weigel and N. K. Glendenning, Phys. Rev. D 51, 1440 (1995) [4] P. Haensel, J.L. Zdunik and R. Schaeffer, Astron. Astrophys. 160, 121 (1986) [5] T. Chmaj, P. Haensel and W. Slomi\'nski, Nuclear Physics B (Proc. Suppl.) 24, 40 (1991) [6] V. V. Usov, Phys. Rev. Lett. 80, 230 (1998) [7] K. S. Cheng and T. Harko, Phys. Rev. D 62, 3001 (2000) [8] T. Harko and K. S. Cheng, Astron. Astrophys. 385, 947 (2002) [9] K. S. Cheng and T. Harko, Astrophys. J. 596, 451 (2003) [10] T. Harko, K. S. Cheng and P. S. Tang, Astrophys. J. 608, 945 (2004) [11] V. V. Usov, T. Harko and K. S. Cheng, Astrophys. J. 620, 915 (2005) [12] T. Harko and K. S. Cheng, Astrophys. J. 622, 1033 (2005)

List of Research Outputs

Boehmer C.G. and Harko T.C., Does the cosmological constant imply the existence of a minimum mass?, Physics Letters B. Amsterdam, Elsevier B.V., 2005, 630: 73-77.

Harko T.C. and Mak M.K., Conformally symmetric vacuum solutions of the gravitational field equations in the brane-world models, Annals of Physics. Elsevier Inc., 2005, 319: 471-492.

Harko T.C. and Cheng K.S., Electron-positron pair production in the electrosphere of quark stars, Astrophysical Journal. The American Astronomical Society, 2006, 643: 318-331.

Harko T.C. and Cheng K.S., Galactic metric, dark radiation, dark pressure, and gravitational lensing in brane world models, The Astrophysical Journal. The American Astronomical Society, 2006, 636: 8-20.

Mak M.K. and Harko T.C., Relativistic compact objects in isotropic coordinates, Pramana-Journal of Physics. Indian Academy of Sciences, 2005, 65: 185-192.

Researcher : He G

List of Research Outputs

He G. and Wang Z.D., Oblivious transfer using quantum entanglement, Physical Review A. New York, The American Physical Society, 2006, 73: 012331: 1-9.

Researcher : Ho KH

List of Research Outputs

Chau H.F., Chow F.K., Ho K.H. and Man W.C., Multiple choice minority game with different publicly known histories, New Journal of Physics. Bristol, IOP Publishing Limited, 2005, 7: 206:1-12.

Man W.C., Ho K.H., Chow F.K. and Chau H.F., The relevance of memory in minority game, Progress of Theoretical Physics Supplement. Japan, 2006, 162: 190-196.

Researcher : Hu F

Project Title:	Resistance switching induced by electric current in epitaxial films of perovskite manganites
Investigator(s):	Hu F, Gao J
Department:	Physics
Source(s) of Funding:	Small Project Funding
Start Date:	09/2005
Completion Date:	02/2007

Abstract:

Colossal magnetoresistance (CMR) effect in mixed-valent perovskite manganites has triggered intense scientific activity in recent years. Phase separation together with concomitant percolation behavior has been supposed to be the core of CMR effect. It has been suggested that the largest MR is associated with spatial inhomogeneity related to multiphase coexistence, which generically causes a sensitivity of physical properties to external perturbations, such as application of magnetic fields, pressure, current bias, or light illumination. The possibility of using a wide range of perturbations to influence the transport properties also increases their technological potential. An increasing interest has been recently attracted to the influence of electric field/current to the transport in CMR materials.[1-4] Significant change of electric resistance induced by static electric field has been demonstrated in La1-xCaxMnO3 using field effect configurations. The observed electroresistance (ER) and CMR effects are found remarkably complementary and strongly favoring a percolative phase separation picture.[1] It has been also observed that an applied current could lead to a transition from the electrically insulating charge-ordered (CO) state to a ferromagnetic (FM) metallic state, even for Y0.5Ca0.5MnO3 in which a large magnetic field ( 40 T) has no effect on the charge-ordered state.[2] Considering the strong effect of external perturbations on the balance of multiphase coexistence, it can be expected that a sufficiently large current flowing and the possible produced magnetic fields could thoroughly disturb the subtle balance of multiphase coexistence and then might induce a new equilibrium state of coexistence. In comparing with bulk samples, a current with a very high density could be easily applied to a micro-bridge of CMR thin films thus the influence of high current density on the multiphase coexistence state can be studied. Recently, we focused on the influence of electric field/current on the transport properties in films of mixed-valent manganites. Remarkable ER effect induced by electric current has been observed even in epitaxial thin films of La0.7Ca0.3MnO3 and La0.85Ba0.15MnO3.[3] Further studies revealed that a current with a high density can significantly affect the balance of multiphase coexistence and cause a series of changes of transport properties.[4] Very recently, we found that a switching from low to high resistive state could be introduced by applying a dc current over a threshold value in epitaxial films of perovskite manganites. Our repeated measurements indicate that the high resistive state appeared in some samples is much stable. Exposing the sample in air and room temperature could not cause any change of the transport properties. However, for some other samples, the induced high resistive state behaves unstable characteristics. Keeping the sample at a low temperature of 20 K, a relaxation to a higher resistive state takes place. Our preliminary analysis indicated that the different resistance switching behavior is related to the different phase-separation characteristic in different systems. The work on the resistance switching behavior is still rather limited. The rich variation of the switching behavior versus temperature, current, and magnetic field in different perovskite manganites remain to be explored. In this proposed research, we will perform a comprehensive study on the current-induced resistance switching in epitaxial films of various manganite perovskites with different phase-separation characteristic. Scientific issues to be addressed: 1. To widely study the resistance switching behavior induced by electric current in epitaxial thin films of various mixed-valent manganite oxides with electronic phase separation. The films with different phase separation characteristic can be prepared by adjusting the kind and content of R and A ions in the formula of R1-xAxMnO3 (where R and A are rare- and alkaline-earth ions, respectively). 2. To study the influence of the strain on the resistance switching behavior. Strain effect, due to substrate, influence the lattice stiffness, Jahn-Teller distortion, and consequently the electronic phase separation. The epitaxial thin films with different thickness can be prepared so as to study the strain effect on the coexistence of multiphases and the current-induced resistance switching. 3. To study the influence of electric field and magnetic field on the switched high resistive state in different systems. Try to understand the physics mechanism behind the current-induced resistance switching. References: [1] T. Wu, et al., Phys. Rev. Lett. 86 (2001) 5998. [2] C. N. R. Rao, et al., Phys. Rev. B 61 (2000) 594. [3] J. Gao, S.Q. Shen, T.K. Li, and J.R. Sun, Appl. Phys. Lett. 82 (2003) 4732. [4] F. X. Hu, J. Gao, Phys. Rev. B 69 (2004) 212413.

List of Research Outputs

Gao J. and Hu F., Effect of magnetic fields on the abnormal electroresistance behavior in epitaxial thin films of La_0.8Ca_0.2MnO₃, Materials Science and Engineering B. Amsterdam, Elsevier B.V., 2006, 126: 250-253.

Gao J., Hu F. and Yao H., Impact of electric currents on the insulator-metal phase transition in epitaxial thin films of La_1-xA_xMnO₃ (A = Sr, Ca, and Ba), Applied Surface Science. Amsterdam, Elsevier B.V., 2006, 252: 5521-5524.

Hu F., Gao J. and Wu X.S., Controllable colossal electroresistance in La_0.8Ca_0.2MnO₃ epitaxial thin films, Physical Review B. New York, The American Physical Society, 2005, 72: 064428:1-5.

Hu F. and Gao J., Current-induced asymmetric transport in La_0.8Ca_0.2MnO₃ epitaxial thin films, Applied Physics Letters. New York, American Institute of Physics, 2005, 87: 152504:1-3.

Hu F., Gao J. and Wang Z.H., Electroresistance and magnetoresistance in La_0.9Ba_0.1MnO₃ thin films, Materials Science and Engineering B. Amsterdam, Elsevier B.V., 2006, 126: 102-105.

Hu F. and Gao J., Investigations on electroresistance effect in epitaxial manganite films using field effect configurations, Applied Physics Letters. New York, American Institute of Physics, 2006, 88: 132502: 1-3.

Hu F. and Gao J., The influence of static-electric field on the transport properties in La_0.7Ca_0.3MnO₃ epitaxial thin films, Journal of Applied Physics. New York, American Institute of Physics, 2006, 99: 08Q314: 1-3.

Yao H., Hu F. and Gao J., Strain effect and current-induced electroresistance in epitaxial thin films of La_0.9Sr_0.1MnO₃, Thin Solid Films. Amsterdam, Elsevier B.V., 2006, 495: 165-168.

Researcher : Huang Y

List of Research Outputs

Chen X., Huang Y., Ling F.C.C., Fung S.H.Y. and Beling C.D., 4-11 Electrical characterization of defects at the gallium nitride based homo- and hetero-junctions, 第十五屆全國半導體物理年會: 論文摘要集, Sichuan, Sichuan University, 2005, 41.

Huang Y., Cheng K.S. and Gao T.T., Modeling the optical afterglow of GRB 030329, The Astrophysical Journal. The American Astronomical Society, 2006, 637: 873-879.

Huang Y., Some studies of structural and point defects in gallium nitride and their influence in determining the properties of the bulk material, its Schottky contacts, P-N junctions and heterostructures. Hong Kong, The University of Hong Kong, 2005, 1-137.

Lu Y., Cheng K.S. and Huang Y., Capture of a red giant by the black hole Sagittarius A* as a possible origin for the TeV gamma rays from the galactic center, The Astrophysical Journal. The American Astronomical Society, 2006, 641: 288-292.

Wang R., Xu S.J., Fung S.H.Y., Beling C.D., Wang K., Li S., Wei Z., Zhou T., Zhang J., Huang Y. and Gong M., Micro-Raman and photoluminescence studies of neutron-irradiated gallium nitride epilayers, Applied Physics Letters. New York, American Institute of Physics, 2005, 87: 031906:1-3.

Researcher : Huang Y

List of Research Outputs

Huang Y., Cheng K.S. and Gao T.T., Modeling the optical afterglow of GRB 030329, The Astrophysical Journal. The American Astronomical Society, 2006, 637: 873-879.

Researcher : Huang Y

List of Research Outputs

Huang Y., Cheng K.S. and Gao T.T., Modeling the optical afterglow of GRB 030329, The Astrophysical Journal. The American Astronomical Society, 2006, 637: 873-879.

Researcher : Jia J

List of Research Outputs

Jia J., The phase-resolved spectra of the crab pulsar. Hong Kong, The University of Hong Kong, 2005, 1-58.

Researcher : Jiang L

List of Research Outputs

Jiang L., Theoretical study of inhomogeneous properties in unconventional superconductors. Hong Kong, The University of Hong Kong, 2005, 1-80.

Researcher : Kwan PYR

List of Research Outputs

Kwan P.Y.R., Cheung C.K., Beling C.D. and Fung S.H.Y., Preliminary studies on a variable energy positron annihilation lifetime spectroscopy system, Applied Surface Science. Amsterdam, Elsevier B.V., 2006, 252: 3138-3142.

Kwan P.Y.R., The focusing of the HKU positron beam, and an extended design for incorporating secondary electron-positron annihilation lifetime spectroscopy. Hong Kong, The University of Hong Kong, 2006, 1-147.

Researcher : Kwong CY

List of Research Outputs

Wang R., Beling C.D., Fung S.H.Y., Djurisic A., Kwong C.Y. and Li S., The effect of thermal annealing on the properties of indium tin oxide thin films, Proceeding of 2004 Conference on Optoelectronic and Microelectronic Materials and Devices, 8-10 December 2004, Australia. IEEE, 2005, 57-60.

Researcher : Lam CH

List of Research Outputs

Lam C.H., Positron annihilation spectroscopy studies of 6H N-type silicon carbide and Zn-doped P-type gallium antimonide. Hong Kong, The University of Hong Kong, 2005, 1-97.

Researcher : Leung JKC

Project Title:	Muon-induced neutron background in Gd-doped liquid scintillator in an underground laboratory
Investigator(s):	Leung JKC, Pun JCS, Chu MC, Luk KB
Department:	Physics
Source(s) of Funding:	Seed Funding Programme for Basic Research
Start Date:	02/2005
Completion Date:	01/2007

Abstract:

Purpose: To study the muon-induced neutron background in Gd-doped liquid scintillator in an underground laboratory inside Aberdeen Tunnel (Aberdeen Lab). Key issues and problems being addressed: Recent discoveries have shown that neutrinos are massive and that it can oscillate between 3 neutrino species (electron neutrino; muon neutrino and tau neutrino). Mixing among the flavours has been observed in atmospheric and solar neutrinos in experiments such as Super-K and SNO as well as in experiments using man-made neutrino sources including KamLAND and K2K. In the neutrino mixing matrix, all but two parameters have been measured: the smallest mixing angle, theta-13, and the value of the CP violating phase, are not yet known. In order to advance our knowledge in neutrino physics and indeed the nature of dark matters in the universe, a few collaborations in the world have been formed and started the race for determining theta-13. China with Hong Kong and US have formed a collaboration to measure the mixing angle using anti-neutrinos produced by the reactors of the Daya Bay and Ling Ao nuclear power plants. (Please refer to http://dayawane.ihep.ac.cn/ for details). We are convinced that the Daya Bay site is the best and most promising one because it is one of the largest reactor groups in the world and the mountain next to the site provides sufficient overburden for minimizing the cosmic background effects. Because of the small interaction cross-section of neutrinos, event rate at the neutrino detectors will be extremely small, hence suppression of background and false events are crucial to the success of the experiments. The reactor neutrino-oscillation experiments, CHOOZ, Palo Verde (Boehm et al, 2000) and the KamLAND (Alivisatos et al, 1998), have shown that muon-induced neutrons are serious background events. In this proposal we will investigate the production and the properties of the background neutrons produced inside a liquid scintillator of the same type that will be used in the future Daya Bay experiment. The experiment will be done inside the Aberdeen Lab which has an overburden of 250 m of rock and geology, close to that of the proposed near-detector sites in the Daya Bay neutrino project. We expect to obtain reliable data within about one and a half year, just good enough to be incorporated into the fabrication of the future Daya Bay detectors. References: Boehm, F., et al, Search for Neutrino Oscillations at the Palo Verde Nuclear Reactors. Phys. Rev. Lett, 84, 3764-3767, 2000. Alivisatos, P. et al., KamLAND: a Liquid Scintillator AntiNeutrino Detector at the Kamioka site. Report No. Stanford-HEP-98-03, Tohoku-RCNS-98-15, 1998.

Project Title:	Hong Kong Radon Map
Investigator(s):	Leung JKC
Department:	Physics
Source(s) of Funding:	Incentive Award for RGC CERG Fundable But Not Funded Projects
Start Date:	07/2005
Completion Date:	06/2006

Abstract:

N/A

List of Research Outputs

Cheng K.Y.R. and Leung J.K.C., Nuclear emergency preparedness model in Hong Kong, The 2nd International Exergy, Energy and Environment Symposium (IEEES2). Greece, KOS, 2005.

Leung S.Y.Y., Nikezic D., Leung J.K.C. and Yu K.N., A study of the polyethylene membrane used in diffusion chambers for radon gas concentration measurements, 6th International Topical Meeting on Industrial Radiation and Radioisotope Measurement Applications. Canada, McMaster University, 2005.

Leung S.Y.Y., Nikezic D., Leung J.K.C. and Yu K.N., Sensitivity of LR 115 SSNTD in a diffusion chamber, 6th International Topical Meeting on Industrial Radiation and Radioisotope Measurement Applications. Canada, McMaster University, 2005.

Yu K.N., Nikezic D., Ng F.M.F., Lau B.M.F. and Leung J.K.C., Long-term measurements of radon progeny concentrations with LR 115 SSNTDs, International Congress Series. Amsterdam, Elsevier B.V., 2005, 1276: 217-218.

Yu K.N., Nikezic D., Ng F.M.F. and Leung J.K.C., Long-term measurements of radon progeny concentrations with solid-state nuclear track detectors, Radiation Measurements. Amsterdam, Elsevier Ltd., 2005, 40: 560-568.

Researcher : Leung YH

List of Research Outputs

Cai X., Leung Y.H., Cheung K.Y., Tam K.H., Djurisic A., Xie M.H., Chen H.Y. and Gwo S., Straight and helical InGaN core-shell nanowires with a high In core content, Nanotechnology. Bristol, IOP Publishing Limited, 2006, 17: 2330-2333.

Djurisic A., Leung Y.H., Tam K.H., Ding L., Ge W.K., Chen H.Y. and Gwo S., Green, yellow, and orange defect emission from ZnO nanostructures: Influence of excitation wavelength, Applied Physics Letters. New York, American Institute of Physics, 2006, 88: 103107: 1-3.

Djurisic A., Kwok W.M., Chan W.K., Phillips D.L., Leung Y.H., Xie M.H., Chen H.Y., Wu C.L. and Gwo S., Optical properties of highly faceted ZnO rods, Journal of Applied Physics. New York, American Institute of Physics, 2006, 99: 033517: 1-6.

Djurisic A., Kwok W.M., Leung Y.H., Phillips D.L. and Chan W.K., Stimulated emission in ZnO nanostructures: A time-resolved study, Journal of Physical Chemistry B. American Chemical Society, 2005, 109: 19228-19233.

Djurisic A., Kwok W.M., Leung Y.H., Chan W.K., Phillips D.L., Lin M.S. and Gwo S., Ultrafast spectroscopy of stimulated emission in single ZnO tetrapod nanowires, Nanotechnology. Bristol, IOP Publishing Limited, 2006, 17: 244-249.

Kwok W.M., Djurisic A., Leung Y.H., Chan W.K., Phillips D.L., Chen H.Y., Wu C.L., Gwo S. and Xie M.H., Study of excitonic emission in highly faceted ZnO rods, Chemical Physics Letters. Amsterdam, Elsevier B.V., 2005, 412: 141-144.

Kwok W.M., Djurisic A., Leung Y.H., Chan W.K. and Phillips D.L., Time-resolved photoluminescence from ZnO nanostructures, Applied Physics Letters. New York, American Institute of Physics, 2005, 87: 223111: 1-3.

Kwok W.M., Djurisic A., Leung Y.H., Chan W.K. and Phillips D.L., Time-resolved photoluminescence study of the stimulated emission in ZnO nanoneedles, Applied Physics Letters. New York, American Institute of Physics, 2005, 87: 093108:1-3.

Kwok W.M., Leung Y.H., Phillips D.L., Chan W.K. and Djurisic A., Ultrafast time - and wavelength - resolved photoluminescence study of stimulated emission on selected ZnO nanostructures , International Chemical Congress of Pacific Basin Societies (PACIFICHEM 2005), Houolulu, Hawaii, U.S.A., Dec 15-20,. 2005.

Kwok W.M., Djurisic A., Leung Y.H., Chan W.K., Lin M.S., Gwo S. and Phillips D.L., Ultrafast time - and wavelength - resolved photoluminescence study of stimulated emission on selected ZnO nanostructures , The 4th Asian Conference on Ultrafast Phenomena, The Hong Kong University of Science and Technology, Hong Kong, January 8-11, 2006.

Leung C.Y., Djurisic A., Leung Y.H., Ding L., Yang C.L. and Ge W.K., Influence of the carrier gas on the luminescence of ZnO tetrapod nanowires, Journal of Crystal Growth. Amsterdam, Elsevier B.V., 2006, 290: 131-136.

Leung Y.H., Fabrication and characterization of zinc oxide (ZnO) nanostructures. Hong Kong, The University of Hong Kong, 2006, 1-95.

Leung Y.H., Djurisic A. and Xie M.H., Non-catalytic synthesis of ZnO nanocolumns with different cross-sections, Journal of Crystal Growth. Amsterdam, Elsevier B.V., 2005, 284: 80-85.

Leung Y.H., Tam K.H., Djurisic A., Xie M.H., Chan W.K., Lu D. and Ge W.K., ZnO nanoshells: synthesis, structure, and optical properties, Journal of Crystal Growth. Amsterdam, Elsevier B.V., 2005, 283: 134-140.

Li D., Leung Y.H., Djurisic A., Liu Z., Xie M.H., Gao J. and Chan W.K., CuO nanostructures prepared by a chemical method, Journal of Crystal Growth. Amsterdam, Elsevier B.V., 2005, 282: 105-111.

Oey C.C., Djurisic A., Wang H., Man K.K.Y., Chan W.K., Xie M.H., Leung Y.H., Pandey A., Nunzi J.M. and Chui P.C., Polymer-TiO₂ solar cells: TiO₂ interconnected network for improved cell performance, Nanotechnology. Bristol, IOP Publishing Limited, 2006, 17: 706-713.

Wang H., Oey C.C., Djurisic A., Xie M.H., Leung Y.H., Man K.K.Y., Chan W.K., Pandey A., Nunzi J.M. and Chui P.C., Titania bicontinuous network structures for solar cell applications, Applied Physics Letters. New York, American Institute of Physics, 2005, 87: 023507:1-3.

Researcher : Leung YH

List of Research Outputs

Leung Y.H., Fabrication and characterization of zinc oxide (ZnO) nanostructures. Hong Kong, The University of Hong Kong, 2006, 1-95.

Leung Y.H., Djurisic A. and Xie M.H., Non-catalytic synthesis of ZnO nanocolumns with different cross-sections, Journal of Crystal Growth. Amsterdam, Elsevier B.V., 2005, 284: 80-85.

Researcher : Li D

List of Research Outputs

Li D., Leung Y.H., Djurisic A., Liu Z., Xie M.H., Gao J. and Chan W.K., CuO nanostructures prepared by a chemical method, Journal of Crystal Growth. Amsterdam, Elsevier B.V., 2005, 282: 105-111.

Researcher : Li G

List of Research Outputs

Shi S., Li G., Xu S.J., Zhao Y. and Chen G., Green luminescence band in ZnO: Fine structures, electron-phonon coupling, and temperature effect, Journal of Physical Chemistry B. American Chemical Society, 2006, 110: 10475-10478.

Xu S.J., Li G., Wang Y., Zhao Y., Chen G., Zhao D.G., Zhu J.J., Yang H., Yu D.P. and Wang J.N., Quantum dissipation and broadening mechanisms due to electron-phonon interactions in self-formed InGaN quantum dots, Applied Physics Letters. New York, American Institute of Physics, 2006, 88: 083123: 1-3.

Xu S.J., Li G., Xiong S. and Che C.M., Temperature dependence of the LO phonon sidebands in free exciton emission of GaN, Journal of Applied Physics. New York, American Institute of Physics, 2006, 99: 073508: 1-5.

Researcher : Li J

List of Research Outputs

Hankiewicz E.M., Li J., Jungwirth T., Niu Q., Shen S.Q. and Sinova J., Charge Hall effect driven by spin-dependent chemical potential gradients and Onsager relations in mesoscopic systems, Physical Review B. New York, The American Physical Society, 2005, 72: 155305:1-5.

Li J., Zhou T. and Wang Z.D., Theoretical investigation of the quasiparticle dispersion of bilayer high-T_c superconductors, Physical Review B. New York, The American Physical Society, 2005, 72: 094515: 1-5.

Li J., Dai X., Shen S.Q. and Zhang F.C., Transverse electric current induced by optically injected spin current in a cross-shaped InGaAs/InAlAs system, Applied Physics Letters. New York, American Institute of Physics, 2006, 88: 162105: 1-3.

Researcher : Li J

List of Research Outputs

Researcher : Li P

List of Research Outputs

Li P., Novel quantum magnetic states in low dimensions. Hong Kong, The University of Hong Kong, 2006, 1-120.

Li P. and Shen S.Q., Spin and orbital valence bond solids in a one-dimensional spin-orbital system: Schwinger boson mean-field theory, Physical Review B. New York, The American Physical Society, 2005, 72: 214439:1-6.

Researcher : Li Q

List of Research Outputs

Li Q., Xu S.J., Xie M.H. and Tong D.S.Y., A model for steady-state luminescence of localized-state ensemble, Europhysics Letters. EDP Sciences, 2005, 71: 994-1000.

Li Q., Xu S.J., Xie M.H. and Tong D.S.Y., Origin of the `S-shaped' temperature dependence of luminescent peaks from semiconductors, Journal of Physics: Condensed Matter. Bristol, Institute of Physics Publishing, 2005, 17: 4853-4858.

Li Q., Xu S.J., Dai D. and Che C.M., Two-photon excited photoluminescence in InGaN multi-quantum-wells structures, Proceeding of 2004 Conference on Optoelectronic and Microelectronic Materials and Devices, 8-10 December 2004, Australia. IEEE, 2005, 153-155.

Wang Y., Xu S.J. and Li Q., Anisotropic ambipolar diffusion of carriers in InGaN/GaN quantum wells, Physica Status Solidi C. Weinheim, WILEY-VCH Verlag GmbH & Co., 2006, 3: 1988-1991.

Wang Y., Xu S.J., Li Q., Zhao D.G. and Yang H., Band gap renormalization and carrier localization effects in InGaN/GaN quantum-wells light emitting diodes with Si doped barriers, Applied Physics Letters. New York, American Institute of Physics, 2006, 88: 041903: 1-3.

Wei Z., Xu S.J., Duan R., Li Q., Wang J., Zeng Y.P. and Liu H.C., Thermal quenching of luminescence from buried and surface InGaAs self-assembled quantum dots with high sheet density, Journal of Applied Physics. New York, American Institute of Physics, 2005, 98: 084305: 1-4.

Yang H., Xu S.J., Li Q. and Zhang J., Resonantly enhanced femtosecond second-harmonic generation and nonlinear luminescence in GaN film grown on sapphire, Applied Physics Letters. New York, American Institute of Physics, 2006, 88: 161113: 1-3.

Researcher : Li Q

List of Research Outputs

Li Q., Xu S.J., Xie M.H. and Tong D.S.Y., A model for steady-state luminescence of localized-state ensemble, Europhysics Letters. EDP Sciences, 2005, 71: 994-1000.

Wang Y., Xu S.J. and Li Q., Anisotropic ambipolar diffusion of carriers in InGaN/GaN quantum wells, Physica Status Solidi C. Weinheim, WILEY-VCH Verlag GmbH & Co., 2006, 3: 1988-1991.

Researcher : Li S

List of Research Outputs

Li S., Zhang J., Beling C.D., Wang K., Wang R., Gong M. and Sarkar C.K., Large lattice relaxation deep levels in neutron-irradiated GaN, Journal of Applied Physics. New York, American Institute of Physics, 2005, 98: 093517: 1-6.

Wang R., Xu S.J., Fung S.H.Y., Beling C.D., Wang K., Li S., Wei Z., Zhou T., Zhang J., Huang Y. and Gong M., Micro-Raman and photoluminescence studies of neutron-irradiated gallium nitride epilayers, Applied Physics Letters. New York, American Institute of Physics, 2005, 87: 031906:1-3.

Wang R., Xu S.J., Li S., Fung S.H.Y., Beling C.D., Wang K., Wei Z., Zhou T., Zhang J., Gong M. and Pang G.K.H., Raman scattering and X-ray diffraction study of neutron irradiated GaN epilayers, Proceeding of 2004 Conference on Optoelectronic and Microelectronic Materials and Devices, 8-10 December 2004, Australia. IEEE, 2005, 141-143.

Wang R., Beling C.D., Fung S.H.Y., Djurisic A., Kwong C.Y. and Li S., The effect of thermal annealing on the properties of indium tin oxide thin films, Proceeding of 2004 Conference on Optoelectronic and Microelectronic Materials and Devices, 8-10 December 2004, Australia. IEEE, 2005, 57-60.

Researcher : Lin LM

List of Research Outputs

Lin L.M., Cheng K.S., Chu M.C. and Suen W.M., Gravitational waves from phase-transition-induced collapse of neutron stars, The Astrophysical Journal. The American Astronomical Society, 2006, 639: 382-396.

Researcher : Ling FCC

Project Title:	Threshold electron energy of defects in silicon carbide induced by electron irradiation: an approach to investigate the microstructures of some defects
Investigator(s):	Ling FCC, Chen X
Department:	Physics
Source(s) of Funding:	Small Project Funding
Start Date:	11/2003
Completion Date:	10/2005

Abstract:

To investigate the defects' physical identities in semiconductor, which plays a crucial role in determining the materials's electrical and optical properties, by monitoring the electron energy dependence of generating these defects in the energy range close to the defects' threshold displacement energies.

Project Title:	Carbon vacancy defect and carbon interstitial defect in silicon carbide: unambiguous determination of their signature photoluminescence lines
Investigator(s):	Ling FCC
Department:	Physics
Source(s) of Funding:	Small Project Funding
Start Date:	11/2004
Completion Date:	10/2006

Abstract:

To measure the signature luminescence lines of the carbon vacancy and the carbon interstitial in the photoluminescence spectrum.

Project Title:	Experimental studies of defects in ZnO: electrical and optical activities of O-vacancy and Zn-vacancy related defects
Investigator(s):	Ling FCC, Xu SJ, Chen X
Department:	Physics
Source(s) of Funding:	Competitive Earmarked Research Grants (CERG)
Start Date:	12/2004

Abstract:

To identify and characterize different defects in as-grown and particle irradiated ZnO. Annealing behaviors of the defects will also be investigated; to study the correlation between the identified defects and to investigate their microstructure; to study the involvement of O-vacancy and Zn-vacancy in PL transition; to study the role of O-vacancy and Zn-vacancy in determining the material electrical properties.

Project Title:	Experimental studies of defects in ZnO: electrical and optical activities of O-vacancy and Zn-vacancy related defects
Investigator(s):	Ling FCC
Department:	Physics
Source(s) of Funding:	Merit Award for RGC CERG Funded Projects
Start Date:	01/2005

Abstract:

N/A

Project Title:	Natures and identities of defects in 6H silicon carbide induced by low energy electron irradiation
Investigator(s):	Ling FCC
Department:	Physics
Source(s) of Funding:	Merit Award for RGC CERG Funded Projects
Start Date:	08/2005

Abstract:

N/A

Project Title:	Natures and identities of defects in 6H silicon carbide induced by low energy electron irradiation
Investigator(s):	Ling FCC, Fung SHY
Department:	Physics
Source(s) of Funding:	Competitive Earmarked Research Grants (CERG)
Start Date:	08/2005

Abstract:

To study the defects in low energy electron irradiated 6H-SiC with the use of positron annihilation spectroscopy, deep level transient spectroscopy, deep level optical spectroscopy and photoluminescence, while bearing the following objectives: (1) Characterize and identify the defects induced in low energy electron irradiated 6H-SiC material, as well as their annealing derivatives; (2) Explore the physical identities of the DLTS signals E1/E2, the PL signals D1 and EA; and (3) Study the role of these defects played in compensating the material, in particular for the case of carbon vacancy related defects.

List of Research Outputs

Beling C.D., Ling F.C.C., Cheung C.K., Naik P.S., Zhang J. and Fung S.H.Y., Positron beam studies of transients in semiconductors, Applied Surface Science. Amsterdam, Elsevier B.V., 2006, 252: 3172-3182.

Chen X., Huang Y., Ling F.C.C., Fung S.H.Y. and Beling C.D., 4-11 Electrical characterization of defects at the gallium nitride based homo- and hetero-junctions, 第十五屆全國半導體物理年會: 論文摘要集, Sichuan, Sichuan University, 2005, 41.

Chen X., Ling F.C.C., Fung S.H.Y., Beling C.D., Mei Y.F., Fu R.K.Y., Siu G.G. and Chu P.K., Current transport studies of ZnO/p-Si heterostructures grown by plasma immersion ion implantation and deposition, Applied Physics Letters. New York, American Institute of Physics, 2006, 88: 132104:1-3.

Ling F.C.C., Chen X., Brauer G., Anwand W., Skorupa W., Wang H. and Weng H.M., Deep-level defects in n-type 6H silicon carbide induced by He implantation, Journal of Applied Physics. New York, American Institute of Physics, 2005, 98: 043508:1-6.

Ling F.C.C., Chen X., Gong M., Yang C.L., Ge W.K. and Wang J.N., Electron energy dependence on inducing the photoluminescence lines of 6H-SiC by electron irradiation, Physica B. Amsterdam, Elsevier B.V., 2006, 376-377: 374-377.

Lui M.K.P. and Ling F.C.C., Liquid encapsulated Czochralski grown undoped p-type gallium antimonide studied by temperature-dependent Hall measurement, Semiconductor Science and Technology. Bristol, Institute of Physics Publishing, 2005, 20: 1157-1161.

Zhong Z.Q., Wu D.X., Gong M., Wang O., Shi S., Xu S.J., Chen X., Ling F.C.C., Fung S.H.Y., Beling C.D., Brauer G., Anwand W. and Skorupa W., Primary photoluminescence in as-neutron (electron) –irradiated n-type 6H-SiC, Journal of Applied Physics. New York, American Institute of Physics, 2006, 99: 093511: 1-3.

Researcher : Liu Y

List of Research Outputs

Liu Y., Heteroepitaxial growth of InN and InGaN alloys on GaN(0001) by molecular beam epitaxy. Hong Kong, The University of Hong Kong, 2005, 1-188.

Liu Y., Xie M.H., Wu H.S. and Tong S.Y., Mass transport and alloying during InN growth on GaN by molecular-beam epitaxy, Applied Physics Letters. New York, American Institute of Physics, 2006, 88: 221916: 1-3.

Researcher : Liu Z

List of Research Outputs

Chan J., Rakic A.D., Kwong C.Y., Liu Z., Djurisic A., Majewski M.L., Chan W.K. and Chui P.C., Device optimization of tris-aluminum (Alq₃) based bilayer organic light emitting diode structures, Smart Materials and Structures. Bristol, IOP Publishing Limited, 2006, 15: S92-S98.

Cheung C.H., Djurisic A., Kwong C.Y., Chan J., Rakic A.D., Tam H.L., Cheah K.W., Liu Z., Chan W.K. and Chui P.C., Dependence of the emission from tris (8-hydroxyquinoline) aluminum based microcavity on device thickness and the emission layer position, Thin Solid Films. Amsterdam, Elsevier B.V., 2005, 489: 235-244.

Li D., Leung Y.H., Djurisic A., Liu Z., Xie M.H., Gao J. and Chan W.K., CuO nanostructures prepared by a chemical method, Journal of Crystal Growth. Amsterdam, Elsevier B.V., 2005, 282: 105-111.

Researcher : Lu Y

List of Research Outputs

Lu Y., Cheng K.S. and Huang Y., Capture of a red giant by the black hole Sagittarius A* as a possible origin for the TeV gamma rays from the galactic center, The Astrophysical Journal. The American Astronomical Society, 2006, 641: 288-292.

Researcher : Lui MKP

List of Research Outputs

Lui M.K.P. and Ling F.C.C., Liquid encapsulated Czochralski grown undoped p-type gallium antimonide studied by temperature-dependent Hall measurement, Semiconductor Science and Technology. Bristol, Institute of Physics Publishing, 2005, 20: 1157-1161.

Researcher : Ma KMS

List of Research Outputs

Ma K.M.S., Structure determination by low energy electron diffraction of GaN films on 6H-SiC(0001) substrate by molecular beam epitaxy. Hong Kong, The University of Hong Kong, 2005, 1-74.

Researcher : Mak MK

List of Research Outputs

Harko T.C. and Mak M.K., Conformally symmetric vacuum solutions of the gravitational field equations in the brane-world models, Annals of Physics. Elsevier Inc., 2005, 319: 471-492.

Mak M.K. and Harko T.C., Relativistic compact objects in isotropic coordinates, Pramana-Journal of Physics. Indian Academy of Sciences, 2005, 65: 185-192.

Researcher : Man WC

List of Research Outputs

Chau H.F., Chow F.K., Ho K.H. and Man W.C., Multiple choice minority game with different publicly known histories, New Journal of Physics. Bristol, IOP Publishing Limited, 2005, 7: 206:1-12.

Man W.C., Analytical and numerical study on agent behaviour in various market structures through the minority game. Hong Kong, The University of Hong Kong, 2005, 1-40.

Man W.C. and Chau H.F., Incorporating inertia into multiagent systems, Physical Review E. New York, The American Physical Society, 2006, 73: 036106:1-9.

Man W.C., Ho K.H., Chow F.K. and Chau H.F., The relevance of memory in minority game, Progress of Theoretical Physics Supplement. Japan, 2006, 162: 190-196.

Researcher : Naik PS

List of Research Outputs

Beling C.D., Ling F.C.C., Cheung C.K., Naik P.S., Zhang J. and Fung S.H.Y., Positron beam studies of transients in semiconductors, Applied Surface Science. Amsterdam, Elsevier B.V., 2006, 252: 3172-3182.

Cheung C.K., Naik P.S., Beling C.D., Fung S.H.Y. and Weng H.M., Performance of a slow positron beam using a hybrid lens design, Applied Surface Science. Amsterdam, Elsevier B.V., 2006, 252: 3132-3137.

Researcher : Ng SC

List of Research Outputs

Ng S.C., Variation of the fine structure constant in 5D Kaluza-Klein theory. Hong Kong, The University of Hong Kong, 2005, 1-63.

Researcher : Pang KY

List of Research Outputs

Pang K.Y., Nucleation and growth of GaN islands by molecular-beam epitaxy. Hong Kong, The University of Hong Kong, 2005, 1-60.

Researcher : Pun JCS

Project Title:	Understanding the nature of Supernova Remnant 1987A
Investigator(s):	Pun JCS
Department:	Physics
Source(s) of Funding:	Competitive Earmarked Research Grants (CERG)
Start Date:	09/2003

Abstract:

To study the Supermove Remnant ( SNR 1987A) in detail to gain insight on the explosion mechanism of the progenitor star, final stages of stellar evolution, and interaction with the circumstellar environment; to study SNR1987A system in detail: the explosion debris, the circumstellar rings, and the interaction between delmis and ring.

Project Title:	Understanding the nature of Supernova Remnant 1987A
Investigator(s):	Pun JCS
Department:	Physics
Source(s) of Funding:	Merit Award for RGC CERG Funded Projects
Start Date:	09/2003

Abstract:

N/A

Project Title:	Radio telescope for physics and astronomy teaching and research
Investigator(s):	Pun JCS
Department:	Physics
Source(s) of Funding:	Leung Kau Kui Research and Teaching Endowment Fund - Teaching Grants
Start Date:	05/2004

Abstract:

Establish the first radio astronomical telescope in Hong Kong, strengthening the leadership of HKU on astronomy education; provide students with an all-rounded training in astronomy education; lay the foundation of radio astronomy research in Hong Kong; strengthen the role of HKU as the leading public voice on issues related to astronomy.

Project Title:	Observational Studies of Supernovae
Investigator(s):	Pun JCS
Department:	Physics
Source(s) of Funding:	Incentive Award for RGC CERG Fundable But Not Funded Projects
Start Date:	07/2004
Completion Date:	08/2005

Abstract:

N/A

Project Title:	Early Evolution of Supernovae
Investigator(s):	Pun JCS
Department:	Physics
Source(s) of Funding:	Incentive Award for RGC CERG Fundable But Not Funded Projects
Start Date:	07/2005
Completion Date:	06/2006

Abstract:

N/A

List of Research Outputs

Graves G.J.M., Challis P.M., Chevalier R.A., Crotts A., Filippenko A.V., Fransson C., Garnavich P., Kirshner R.P., Li W.D., Lundqvist P., McCray R., Panagia N., Phillips M.M., Pun J.C.S., Schmidt B.P., Sonneborn G., Suntzeff N.B., Wang L.F. and Wheeler J.C., Limits from the Hubble Space Telescope on a point source in SN 1987A, The Astrophysical Journal. The American Astronomical Society, 2005, 629: 944-959.

Heng K., McCray R., Zhekov S.A., Challis P.M., Chevalier R.A., Crotts A.P.S., Fransson C., Garnavich P., Kirshner R.P., Lawrence S.S., Lundqvist P., Panagia N., Pun J.C.S., Smith N., Sollerman J. and Wang L.F., Evolution of the reverse shock emission from SNR 1987A, The Astrophysical Journal. The American Astronomical Society, 2006, 644: 959-970.

Tam P.H., Cheng K.S., Wang X.Y., Huang Y.F. and Pun J.C.S., Gamma-ray burst afterglows with cylindrical jet geometry, IL Nuovo Cimento C. Bologna, Società Italiana di Fisica, 2005, 28: 447-450.

Wang W., Pun J.C.S. and Cheng K.S., Could electron-positron annihilation lines in the Galactic center result from pulsar winds?, Astronomy & Astrophysics. EDP Sciences, 2006, 446: 943-948.

Researcher : Ren W

List of Research Outputs

Ren W., Wang J. and Ma Z.S., Conductance fluctuations and higher order moments of a disordered carbon nanotube, Physical Review B. New York, The American Physical Society, 2005, 72: 195407:1-6.

Ren W., Wang J., Ma Z.S. and Guo H., Effect of thermal fluctuations of twist angles on charge transport in DNA: A model calculation, Physical Review B. New York, The American Physical Society, 2005, 72: 035456:1-5.

Researcher : Rice TM

List of Research Outputs

Yang K., Rice T.M. and Zhang F.C., Phenomenological theory of the pseudogap state, Physical Review B. New York, The American Physical Society, 2006, 73: 174501: 1-10.

Researcher : Shangguan M

List of Research Outputs

Shangguan M., Sun Q., Wang J. and Guo H., Generating spin current using an ac magnetic field, Physical Review B. New York, The American Physical Society, 2006, 73: 125349:1-5.

Researcher : Shen S

Project Title:	Quantum ordered and disordered states in spin systems with orbital degeneracy
Investigator(s):	Shen SQ, Zhang F.C.
Department:	Physics
Source(s) of Funding:	Competitive Earmarked Research Grants (CERG)
Start Date:	09/2002
Completion Date:	08/2005

Abstract:

This project attempts to understand the role of electronic orbital degree of freedom in formation of various novel quantum states in transition metal oxides, and to develop new theoretical techniques to study the quantum spin liquid states and incommensurate spin density wave states.

Project Title:	Decoherence and non-exponential relaxation of quantum tunnelling in nano-magnetic molecules
Investigator(s):	Shen SQ, Chen Z
Department:	Physics
Source(s) of Funding:	Small Project Funding
Start Date:	11/2002

Abstract:

To understand the physical mechanism of decoherence and non-exponential relaxation in quantum tunnelling in nano-magnetic molecules.

Project Title:	Local stray field and macroscopic quantum tunneling in nanometer-sized magnetic particles and clusters
Investigator(s):	Shen SQ
Department:	Physics
Source(s) of Funding:	Competitive Earmarked Research Grants (CERG)
Start Date:	10/2003

Abstract:

To understand the role of environmental interaction in quantum tunneling and decoherence from the magnetization reversal in nanometer-sized clusters, to establish an efficient method to deduce microscopic parameters from the experimental data, to study the novel properties of newly synthesized supramolecular dimers, and to explore possible application in magnetic memory and information industry.

Project Title:	Local stray field and macroscopic quantum tunneling in nanometer-sized magnetic particles and clusters
Investigator(s):	Shen SQ
Department:	Physics
Source(s) of Funding:	Merit Award for RGC CERG Funded Projects
Start Date:	10/2003

Abstract:

N/A

Project Title:	Quantum spin transport and geometric phases
Investigator(s):	Shen SQ
Department:	Physics
Source(s) of Funding:	Small Project Funding
Start Date:	11/2003

Abstract:

To understand the relation between quantum spin transport and geometric phases in some mesocopic structures where spin and charge currents could arise from the spin interference.

Project Title:	Exact real space renormalization group transformation and its application to the spin and electron lattice systems
Investigator(s):	Shen SQ
Department:	Physics
Source(s) of Funding:	Competitive Earmarked Research Grants (CERG)
Start Date:	10/2004

Abstract:

To develop a non-perturbative theory for the spin and electron lattices in strongly correlated electron systems.

Project Title:	Generation and coherent control of spin current in metals and semiconductors
Investigator(s):	Shen SQ
Department:	Physics
Source(s) of Funding:	Small Project Funding
Start Date:	11/2004

Abstract:

To investigate spin transport in metals and semiconductors, and to explore possible measurement of pure spin current.

Project Title:	Exact real space renormalization group transformation and its application to the spin and electron lattice systems
Investigator(s):	Shen SQ
Department:	Physics
Source(s) of Funding:	Merit Award for RGC CERG Funded Projects
Start Date:	01/2005

Abstract:

N/A

Project Title:	Spin coherent transport of electrons in metals and semiconductors
Investigator(s):	Shen SQ
Department:	Physics
Source(s) of Funding:	Merit Award for RGC CERG Funded Projects
Start Date:	09/2005

Abstract:

N/A

Project Title:	Spin coherent transport of electrons in metals and semiconductors
Investigator(s):	Shen SQ
Department:	Physics
Source(s) of Funding:	Competitive Earmarked Research Grants (CERG)
Start Date:	09/2005

Abstract:

The primary objective of this proposal is to investigate spin coherent transport of electrons, especially how to generate and control spin current of electrons in metals and semiconductors.

List of Research Outputs

Researcher : Shen SQ

Project Title:	Quantum ordered and disordered states in spin systems with orbital degeneracy
Investigator(s):	Shen SQ, Zhang F.C.
Department:	Physics
Source(s) of Funding:	Competitive Earmarked Research Grants (CERG)
Start Date:	09/2002
Completion Date:	08/2005

Abstract:

Project Title:	Decoherence and non-exponential relaxation of quantum tunnelling in nano-magnetic molecules
Investigator(s):	Shen SQ, Chen Z
Department:	Physics
Source(s) of Funding:	Small Project Funding
Start Date:	11/2002

Abstract:

To understand the physical mechanism of decoherence and non-exponential relaxation in quantum tunnelling in nano-magnetic molecules.

Project Title:	Local stray field and macroscopic quantum tunneling in nanometer-sized magnetic particles and clusters
Investigator(s):	Shen SQ
Department:	Physics
Source(s) of Funding:	Competitive Earmarked Research Grants (CERG)
Start Date:	10/2003

Abstract:

Project Title:	Local stray field and macroscopic quantum tunneling in nanometer-sized magnetic particles and clusters
Investigator(s):	Shen SQ
Department:	Physics
Source(s) of Funding:	Merit Award for RGC CERG Funded Projects
Start Date:	10/2003

Abstract:

N/A

Project Title:	Quantum spin transport and geometric phases
Investigator(s):	Shen SQ
Department:	Physics
Source(s) of Funding:	Small Project Funding
Start Date:	11/2003

Abstract:

To understand the relation between quantum spin transport and geometric phases in some mesocopic structures where spin and charge currents could arise from the spin interference.

Project Title:	Exact real space renormalization group transformation and its application to the spin and electron lattice systems
Investigator(s):	Shen SQ
Department:	Physics
Source(s) of Funding:	Competitive Earmarked Research Grants (CERG)
Start Date:	10/2004

Abstract:

To develop a non-perturbative theory for the spin and electron lattices in strongly correlated electron systems.

Project Title:	Generation and coherent control of spin current in metals and semiconductors
Investigator(s):	Shen SQ
Department:	Physics
Source(s) of Funding:	Small Project Funding
Start Date:	11/2004

Abstract:

To investigate spin transport in metals and semiconductors, and to explore possible measurement of pure spin current.

Project Title:	Exact real space renormalization group transformation and its application to the spin and electron lattice systems
Investigator(s):	Shen SQ
Department:	Physics
Source(s) of Funding:	Merit Award for RGC CERG Funded Projects
Start Date:	01/2005

Abstract:

N/A

Project Title:	Spin coherent transport of electrons in metals and semiconductors
Investigator(s):	Shen SQ
Department:	Physics
Source(s) of Funding:	Merit Award for RGC CERG Funded Projects
Start Date:	09/2005

Abstract:

N/A

Project Title:	Spin coherent transport of electrons in metals and semiconductors
Investigator(s):	Shen SQ
Department:	Physics
Source(s) of Funding:	Competitive Earmarked Research Grants (CERG)
Start Date:	09/2005

Abstract:

The primary objective of this proposal is to investigate spin coherent transport of electrons, especially how to generate and control spin current of electrons in metals and semiconductors.

List of Research Outputs

Bao Y., Zhuang H., Shen S.Q. and Zhang F.C., Edge spin current and spin polarization in quantum Hall regime, Physical Review B. New York, The American Physical Society, 2005, 72: 245323:1-5.

Chen Z. and Shen S.Q., Non-exponential relaxation and the distribution of the second-order transverse anisotropic parameters in Mn₁₂, European Physical Journal B. EDP Sciences, 2005, 48: 405-408.

Hankiewicz E.M., Li J., Jungwirth T., Niu Q., Shen S.Q. and Sinova J., Charge Hall effect driven by spin-dependent chemical potential gradients and Onsager relations in mesoscopic systems, Physical Review B. New York, The American Physical Society, 2005, 72: 155305:1-5.

Li H., Shen S.Q., Liang J.Q. and Liu W.M., Quantum dynamics of a vortex in a Josephson junction, Physical Review B. New York, The American Physical Society, 2005, 72: 014546:1-6.

Li J., Dai X., Shen S.Q. and Zhang F.C., Transverse electric current induced by optically injected spin current in a cross-shaped InGaAs/InAlAs system, Applied Physics Letters. New York, American Institute of Physics, 2006, 88: 162105: 1-3.

Li P. and Shen S.Q., Spin and orbital valence bond solids in a one-dimensional spin-orbital system: Schwinger boson mean-field theory, Physical Review B. New York, The American Physical Society, 2005, 72: 214439:1-6.

Shen S.Q., Invited Talk: Spin transverse force on spin current, Workshop on semiconductor nano-spintronics: spin Hall effect and related issues, Asia Pacific Centre of Theoretical Physics, Korea. 2005.

Shen S.Q., Invited talk: Spin transverse force on spin current in electric field, Croucher Advanced Institute: Science and Application of Spintronics, Hong Kong. 2005.

Shen S.Q., Plenary Talk: Spintronics and Spin Current, 13th Conference of Condensed Matter Theory and Statistical Physics, Yinchuang, China, August 2005. 2005.

Shen S.Q., Spin transverse force on spin current in an electric field, Physical Review Letters. New York, The American Physical Society, 2005, 95: 187203:1-4.

Sinova J., Murakami S., Shen S.Q. and Choi M.S., Spin-Hall effect: Back to the beginning at a higher level, Solid State Communications. Elsevier Ltd., 2006, 138: 214-217.

Su Y.C., Shen S.Q. and Tao R.B., Ground state tunneling and staircase hysteresis loop in molecular magnet Mn₁₂ acetate, Journal of Magnetism and Magnetic Materials. Amsterdam, Elsevier B.V., 2006, 299: 376-382.

Zhou B., Ren L. and Shen S.Q., Spin transverse force and intrinsic quantum transverse transport, Physical Review B. New York, The American Physical Society, 2006, 73: 165303:1-7.

Researcher : Shi S

List of Research Outputs

Dai D., Xu S.J., Shi S., Xie M.H. and Che C.M., Efficient multiphoton-absorption-induced luminescence in single-crystalline ZnO at room temperature, Optics Letters. Washington, Optical Society of America, 2005, 30: 3377-3379.

Shi S., Li G., Xu S.J., Zhao Y. and Chen G., Green luminescence band in ZnO: Fine structures, electron-phonon coupling, and temperature effect, Journal of Physical Chemistry B. American Chemical Society, 2006, 110: 10475-10478.

Shi S., Xu S.J., Wang X. and Chen G., Theoretical absorption spectra of silicon carbide nanocrystals, Thin Solid Films. Amsterdam, Elsevier B.V., 2006, 495: 404-406.

Xu S.J., Xiong S.J., Shi S. and Jin K.J., Fano resonance in phonon-assisted photoluminescence spectra of wide gap polar semiconductors, 20th Congress of the International Commission for Optics. CD-ROM, 2005, 6029: 0600-08.

Xu S.J., Xiong S. and Shi S., Resonant coupling of bound excitons with LO phonons in ZnO: Excitonic polaron states and Fano interference, The Journal of Chemical Physics. New York, American Institute of Physics, 2005, 123: 221105: 1-5.

Zhong Z.Q., Wu D.X., Gong M., Wang O., Shi S., Xu S.J., Chen X., Ling F.C.C., Fung S.H.Y., Beling C.D., Brauer G., Anwand W. and Skorupa W., Primary photoluminescence in as-neutron (electron) –irradiated n-type 6H-SiC, Journal of Applied Physics. New York, American Institute of Physics, 2006, 99: 093511: 1-3.

Researcher : So SM

List of Research Outputs

So S.M., Fabrication and transport properties of ramp-type YBa₂Cu₃O_7-d/Nd₂CuO₄/YBa₂Cu₃O_7-d Josephson junctions. Hong Kong, The University of Hong Kong, 2005, 1-158.

Researcher : Suen WM

List of Research Outputs

Lin L.M., Cheng K.S., Chu M.C. and Suen W.M., Gravitational waves from phase-transition-induced collapse of neutron stars, The Astrophysical Journal. The American Astronomical Society, 2006, 639: 382-396.

Researcher : Sun J

List of Research Outputs

Gao J., Sun J. and Yang J., Transport and interface properties in ramp-type Josephson junctions with a graded Y_1-xPr_xBa₂Cu₃O_y barrier, Physica C. Amsterdam, Elsevier B.V., 2006, 436: 86-92.

Researcher : Sun Q

List of Research Outputs

Shangguan M., Sun Q., Wang J. and Guo H., Generating spin current using an ac magnetic field, Physical Review B. New York, The American Physical Society, 2006, 73: 125349:1-5.

Researcher : Tam KH

List of Research Outputs

Cai X., Leung Y.H., Cheung K.Y., Tam K.H., Djurisic A., Xie M.H., Chen H.Y. and Gwo S., Straight and helical InGaN core-shell nanowires with a high In core content, Nanotechnology. Bristol, IOP Publishing Limited, 2006, 17: 2330-2333.

Djurisic A., Leung Y.H., Tam K.H., Ding L., Ge W.K., Chen H.Y. and Gwo S., Green, yellow, and orange defect emission from ZnO nanostructures: Influence of excitation wavelength, Applied Physics Letters. New York, American Institute of Physics, 2006, 88: 103107: 1-3.

Leung Y.H., Tam K.H., Djurisic A., Xie M.H., Chan W.K., Lu D. and Ge W.K., ZnO nanoshells: synthesis, structure, and optical properties, Journal of Crystal Growth. Amsterdam, Elsevier B.V., 2005, 283: 134-140.

Researcher : Tam PH

List of Research Outputs

Tam P.H., Cheng K.S., Wang X.Y., Huang Y.F. and Pun J.C.S., Gamma-ray burst afterglows with cylindrical jet geometry, IL Nuovo Cimento C. Bologna, Società Italiana di Fisica, 2005, 28: 447-450.

Researcher : Teo CYJ

List of Research Outputs

Teo C.Y.J. and Wang Z.D., Geometric phase in eigenspace evolution of invariant and adiabatic action operators, Physical Review Letters. New York, The American Physical Society, 2005, 95: 050406:1-4.

Researcher : Tong DSY

List of Research Outputs

Li Q., Xu S.J., Xie M.H. and Tong D.S.Y., A model for steady-state luminescence of localized-state ensemble, Europhysics Letters. EDP Sciences, 2005, 71: 994-1000.

Li Q., Xu S.J., Xie M.H. and Tong D.S.Y., Origin of the `S-shaped' temperature dependence of luminescent peaks from semiconductors, Journal of Physics: Condensed Matter. Bristol, Institute of Physics Publishing, 2005, 17: 4853-4858.

Researcher : Tsang KV

List of Research Outputs

Tsang K.V., A search for periodic neutrino signals and gamma-ray burst neutrinos with the sudbury neutrino observatory. Hong Kong, The University of Hong Kong, 2005, 1-54.

Researcher : Wang B

List of Research Outputs

Wang B., Peng J., Xing D.Y. and Wang J., Spin current due to spinlike Andreev reflection, Physical Review Letters. New York, The American Physical Society, 2005, 95: 086608:1-4.

Wei Y.D., Zhao X., Wang B. and Wang J., Negative electrochemical capacitance for a double-quantum-dot device, Journal of Applied Physics. New York, American Institute of Physics, 2005, 98: 086103:1-3.

Researcher : Wang H

List of Research Outputs

Djurisic A., Wang H., Chan W.K. and Xie M.H., Characterization of block copolymers using scanning probe microscopy, Journal of Scanning Probe Microscopy. American Scientific Publishers, 2006, 1: 21-31.

Ling F.C.C., Chen X., Brauer G., Anwand W., Skorupa W., Wang H. and Weng H.M., Deep-level defects in n-type 6H silicon carbide induced by He implantation, Journal of Applied Physics. New York, American Institute of Physics, 2005, 98: 043508:1-6.

Oey C.C., Djurisic A., Wang H., Man K.K.Y., Chan W.K., Xie M.H., Leung Y.H., Pandey A., Nunzi J.M. and Chui P.C., Polymer-TiO₂ solar cells: TiO₂ interconnected network for improved cell performance, Nanotechnology. Bristol, IOP Publishing Limited, 2006, 17: 706-713.

Wang H., Djurisic A., Chan W.K. and Xie M.H., Factors affecting phase and height contrast of diblock copolymer PS-b-PEO thin films in dynamic force mode atomic force microscopy, Applied Surface Science. Amsterdam, Elsevier B.V., 2005, 252: 1092-1100.

Wang H., Djurisic A., Xie M.H., Chan W.K. and Kutsay O., Morphology evolution of an asymmetric diblock copolymer P(S-b-MMA) as a function of film thickness and annealing time, International Journal of Nanoscience. Singapore, World Scientific, 2005, 4: 737-743.

Wang H., Djurisic A., Xie M.H., Chan W.K. and Kutsay O., Perpendicular domains in poly(styrene-b-methyl methacrylate) block copolymer films on preferential surfaces, Thin Solid Films. Amsterdam, Elsevier B.V., 2005, 488: 329-336.

Wang H., Oey C.C., Djurisic A., Xie M.H., Leung Y.H., Man K.K.Y., Chan W.K., Pandey A., Nunzi J.M. and Chui P.C., Titania bicontinuous network structures for solar cell applications, Applied Physics Letters. New York, American Institute of Physics, 2005, 87: 023507:1-3.

Researcher : Wang H

List of Research Outputs

Researcher : Wang J

Project Title:	First principle study of I-V characteristics of nanoclusters and compound semiconductor nanowires
Investigator(s):	Wang J
Department:	Physics
Source(s) of Funding:	Competitive Earmarked Research Grants (CERG)
Start Date:	09/2002
Completion Date:	08/2005

Abstract:

Nanometer electro-mechanical systems (NEMS) technology holds the promise of molecular computing, along with new classes of devices for ultra-sensitive probes and detectors. The project aims at investigating the fundamental properties of NEMS by exploiting a new, powerful and possibly unique simulation tool that can generate ab initio I-V curves self-consistently at a density functional level. The code is suitable for open quantum systems and uses a real-space orbital basis set, and constructs the charge density from non-equilibrium Green's functions. With this code, the research team will explore the transport properties such as the dynamic conductance, electrochemical capacitance, as well as I-V curves of paradigmatic NEMS devices based on nanoclusters.

Project Title:	Theoretical investigation of dynamic response, fluctuations, and charge relaxation in nano-conductors
Investigator(s):	Wang J
Department:	Physics
Source(s) of Funding:	Small Project Funding
Start Date:	11/2002
Completion Date:	10/2005

Abstract:

To develop a general current conserving and gauge invariant transport theory for the nanoscopic systems using the non-equilibrium Green's function approach when the system is driven to far from equilibrium.

Project Title:	First principle calculation of transport properties of hybrid superconducting nanostructures
Investigator(s):	Wang J
Department:	Physics
Source(s) of Funding:	Competitive Earmarked Research Grants (CERG)
Start Date:	09/2003

Abstract:

To study DC transport through hybrid superconducting nanostructures; to study AC cument through hybrid superconducting nanostructures; to study the shot noise of hybrid superconducting nanostructures.

Project Title:	First principle calculation of transport properties of hybrid superconducting nanostructures
Investigator(s):	Wang J
Department:	Physics
Source(s) of Funding:	Merit Award for RGC CERG Funded Projects
Start Date:	09/2003

Abstract:

N/A

Project Title:	Parametric pumping in nanostructures
Investigator(s):	Wang J
Department:	Physics
Source(s) of Funding:	Small Project Funding
Start Date:	11/2003
Completion Date:	09/2006

Abstract:

To extend the previous parametric electron pumping theory to include the spin polarized pumping effect, and to examine the spin valve effect for the pumped current.

Project Title:	The noise spectrum of spin current
Investigator(s):	Wang J
Department:	Physics
Source(s) of Funding:	Competitive Earmarked Research Grants (CERG)
Start Date:	09/2004

Abstract:

To focus on the shot noise of the spin cument generated by various parametric quantum spin pumps such as these pumps with or without the spin flipping mechanism, with or without strong electron and electron interaction; to explore novel ways of generating spin cument in orderto study the correlation of the spin current.

Project Title:	Spin current in nanostructures
Investigator(s):	Wang J
Department:	Physics
Source(s) of Funding:	Small Project Funding
Start Date:	11/2004
Completion Date:	09/2006

Abstract:

To examine the possibility of SFET operation without involving magnetic materials and to exploit such a novel SFET which operates purely on spin current.

Project Title:	The noise spectrum of spin current
Investigator(s):	Wang J
Department:	Physics
Source(s) of Funding:	Merit Award for RGC CERG Funded Projects
Start Date:	01/2005

Abstract:

N/A

Project Title:	Time dependent transport through molecular devices
Investigator(s):	Wang J
Department:	Physics
Source(s) of Funding:	Merit Award for RGC CERG Funded Projects
Start Date:	12/2005

Abstract:

N/A

Project Title:	Time dependent transport through molecular devices
Investigator(s):	Wang J
Department:	Physics
Source(s) of Funding:	Competitive Earmarked Research Grants (CERG)
Start Date:	12/2005

Abstract:

The objective of this project is to study the time-dependent current driven by two kinds of ac bias: periodic field and pulse-like aperiodic field, from which one can obtain the information of the response time as well as the dynamical nature of the system. In order to achieve this, one has to solve a general time-dependent transport problem using Keldysh non-equilibrium Green’s function approach combined with the density function theory.

List of Research Outputs

Ren W., Wang J. and Ma Z.S., Conductance fluctuations and higher order moments of a disordered carbon nanotube, Physical Review B. New York, The American Physical Society, 2005, 72: 195407:1-6.

Ren W., Wang J., Ma Z.S. and Guo H., Effect of thermal fluctuations of twist angles on charge transport in DNA: A model calculation, Physical Review B. New York, The American Physical Society, 2005, 72: 035456:1-5.

Shangguan M., Sun Q., Wang J. and Guo H., Generating spin current using an ac magnetic field, Physical Review B. New York, The American Physical Society, 2006, 73: 125349:1-5.

Wan L.H., Wei Y.D. and Wang J., Shot noise in a superconducting hybrid molecular device, Nanotechnology. Bristol, IOP Publishing Limited, 2006, 17: 489-495.

Wang B., Peng J., Xing D.Y. and Wang J., Spin current due to spinlike Andreev reflection, Physical Review Letters. New York, The American Physical Society, 2005, 95: 086608:1-4.

Wang B., Xing Y.X., Wei Y.D., Wan L.H. and Wang J., The thermoelectric transport through carbon chains, Carbon. Amsterdam, Elsevier Ltd., 2005, 43: 2786-2791.

Wang J., First Principle Study On Quantum Transport Through Normal Superconducting Interface, The First Atomistix Conference On Modelling Nanotechnology Systems, Copenhagen, Denmark. 2005.

Wei Y.D., Zhao X., Wang B. and Wang J., Negative electrochemical capacitance for a double-quantum-dot device, Journal of Applied Physics. New York, American Institute of Physics, 2005, 98: 086103:1-3.

Wei Z., Xu S.J., Duan R., Li Q., Wang J., Zeng Y.P. and Liu H.C., Thermal quenching of luminescence from buried and surface InGaAs self-assembled quantum dots with high sheet density, Journal of Applied Physics. New York, American Institute of Physics, 2005, 98: 084305: 1-4.

Wu J., Wang B.G., Wang J. and Guo H., Giant enhancement of dynamic conductance in molecular devices, Physical Review B. New York, The American Physical Society, 2005, 72: 195324:1-5.

Xing Y.X., Sun Q.F. and Wang J., Nature of spin Hall effect in a finite ballistic two-dimensional system with Rashba and Dresselhaus spin-orbit interaction, Physical Review B. New York, The American Physical Society, 2006, 73: 205339: 1-4.

Xu Y., Wang J. and Xu S.J., Quantum transport through C₄₈N₁₂ based atomic devices, The Journal of Chemical Physics. New York, American Institute of Physics, 2006, 124: 114702:1-6.

Yu Y.J., Wei Y.D. and Wang J., Carbon nanotube-based quantum spin pump, New Journal of Physics. IOP Publishing Ltd, 2006, 8: 1-10.

Zhao H., Wang J. and Wang Q., Charge and spin currents tunnelling through a toroidal carbon nanotube side-coupled with a quantum dot, European Physical Journal B. EDP Sciences, 2006, 51: 425-433.

Researcher : Wang K

List of Research Outputs

Li S., Zhang J., Beling C.D., Wang K., Wang R., Gong M. and Sarkar C.K., Large lattice relaxation deep levels in neutron-irradiated GaN, Journal of Applied Physics. New York, American Institute of Physics, 2005, 98: 093517: 1-6.

Wang R., Xu S.J., Fung S.H.Y., Beling C.D., Wang K., Li S., Wei Z., Zhou T., Zhang J., Huang Y. and Gong M., Micro-Raman and photoluminescence studies of neutron-irradiated gallium nitride epilayers, Applied Physics Letters. New York, American Institute of Physics, 2005, 87: 031906:1-3.

Wang R., Xu S.J., Li S., Fung S.H.Y., Beling C.D., Wang K., Wei Z., Zhou T., Zhang J., Gong M. and Pang G.K.H., Raman scattering and X-ray diffraction study of neutron irradiated GaN epilayers, Proceeding of 2004 Conference on Optoelectronic and Microelectronic Materials and Devices, 8-10 December 2004, Australia. IEEE, 2005, 141-143.

Researcher : Wang K

List of Research Outputs

Researcher : Wang R

List of Research Outputs

Li S., Zhang J., Beling C.D., Wang K., Wang R., Gong M. and Sarkar C.K., Large lattice relaxation deep levels in neutron-irradiated GaN, Journal of Applied Physics. New York, American Institute of Physics, 2005, 98: 093517: 1-6.

Wang R., Djurisic A., Beling C.D. and Fung S.H.Y., Indium Tin Oxide (ITO) thin films: Fabrication, properties, post-deposition treatments and applications, In: Elliot T.B., Trends in Semiconductor Research. Nova Science Publishers, Inc., 2005, Chapter 6: 137-174.

Wang R., Xu S.J., Fung S.H.Y., Beling C.D., Wang K., Li S., Wei Z., Zhou T., Zhang J., Huang Y. and Gong M., Micro-Raman and photoluminescence studies of neutron-irradiated gallium nitride epilayers, Applied Physics Letters. New York, American Institute of Physics, 2005, 87: 031906:1-3.

Wang R., Xu S.J., Li S., Fung S.H.Y., Beling C.D., Wang K., Wei Z., Zhou T., Zhang J., Gong M. and Pang G.K.H., Raman scattering and X-ray diffraction study of neutron irradiated GaN epilayers, Proceeding of 2004 Conference on Optoelectronic and Microelectronic Materials and Devices, 8-10 December 2004, Australia. IEEE, 2005, 141-143.

Wang R., Beling C.D., Fung S.H.Y., Djurisic A., Kwong C.Y. and Li S., The effect of thermal annealing on the properties of indium tin oxide thin films, Proceeding of 2004 Conference on Optoelectronic and Microelectronic Materials and Devices, 8-10 December 2004, Australia. IEEE, 2005, 57-60.

Researcher : Wang X

List of Research Outputs

Wang X., Cheng K.S., Dai Z.G. and Lu T., High-energy component of GRB 941017 revisited and the reverse-shock synchrotron self-Compton emission, Astronomy & Astrophysics. ESO, 2005, 439: 957-961.

Wang X. and Wang Z.D., Thermal entanglement in ferrimagnetic chains, Physical Review A (Brief Reports). New York, The American Physical Society, 2006, 73: 064302: 1-3.

Researcher : Wang X

List of Research Outputs

Wang X. and Wang Z.D., Thermal entanglement in ferrimagnetic chains, Physical Review A (Brief Reports). New York, The American Physical Society, 2006, 73: 064302: 1-3.

Researcher : Wang Y

List of Research Outputs

Wang Y., Xu S.J. and Li Q., Anisotropic ambipolar diffusion of carriers in InGaN/GaN quantum wells, Physica Status Solidi C. Weinheim, WILEY-VCH Verlag GmbH & Co., 2006, 3: 1988-1991.

Wang Y., Xu S.J., Li Q., Zhao D.G. and Yang H., Band gap renormalization and carrier localization effects in InGaN/GaN quantum-wells light emitting diodes with Si doped barriers, Applied Physics Letters. New York, American Institute of Physics, 2006, 88: 041903: 1-3.

Wang Y., Wang Z.D. and Sun C.P., Quantum storage and information transfer with superconducting qubits, Physical Review B (Brief Reports). New York, The American Physical Society, 2005, 72: 172507: 1-4.

Xu S.J., Li G., Wang Y., Zhao Y., Chen G., Zhao D.G., Zhu J.J., Yang H., Yu D.P. and Wang J.N., Quantum dissipation and broadening mechanisms due to electron-phonon interactions in self-formed InGaN quantum dots, Applied Physics Letters. New York, American Institute of Physics, 2006, 88: 083123: 1-3.

Researcher : Wang Y

List of Research Outputs

Wang Y., Xu S.J. and Li Q., Anisotropic ambipolar diffusion of carriers in InGaN/GaN quantum wells, Physica Status Solidi C. Weinheim, WILEY-VCH Verlag GmbH & Co., 2006, 3: 1988-1991.

Researcher : Wang Z

Project Title:	Superconductor science and technology
Investigator(s):	Wang ZD
Department:	Physics
Source(s) of Funding:	Matching Fund for National Key Basic Research Development Scheme (973 Projects)
Start Date:	02/2002

Abstract:

To carry out investigation on superconductor science and technology.

Project Title:	Quantum logic gates based on cyclic geometric phases
Investigator(s):	Wang ZD
Department:	Physics
Source(s) of Funding:	Small Project Funding
Start Date:	11/2002

Abstract:

To design a set of quantum logic gates in quantum computing operations with fast running speed based on cyclic geometric phases, which may provide a method to overcome the intrinsic difficulty in adiabatic geometric operations associated with the slow gate speed.

Project Title:	Theoretical studies of impurity and vortex states in high temperature superconductors
Investigator(s):	Wang ZD
Department:	Physics
Source(s) of Funding:	Competitive Earmarked Research Grants (CERG)
Start Date:	09/2003

Abstract:

To carry out a systematic and detailed study on the mechanism of IRS in high temperature superconductors(HTS) with particular attention being paid to its magnetic-related origin. It is expected that the study of the variation of IRS with the doping content and accordingly the response of the local moments carried/induced by impurities to the anti-ferromagnetic correlations may help us to clarify the origin of the IRS in HTS; to study theoretically (a) the local electronic structure at vortex cores and the vortex charge in the presence of the orbital AF phase(d-density wave) recently proposed to explain the PG state; and (b) the variation of IRS in response to various spin or charge order parameters by pinning vortices on the imputities as the resonance state is very sensitive to the nature of the electronic structure where the impurity is embedded. In terms of our results, we may be able to understand profoundly some existing experimental results as well as to suggest new experiments to test some predictions.

Project Title:	Theoretical studies of impurity and vortex states in high temperature superconductors
Investigator(s):	Wang ZD
Department:	Physics
Source(s) of Funding:	Merit Award for RGC CERG Funded Projects
Start Date:	09/2003

Abstract:

N/A

Project Title:	Vortex state and impurity effect in newly discovered NaCoO superconductors
Investigator(s):	Wang ZD
Department:	Physics
Source(s) of Funding:	Small Project Funding
Start Date:	11/2003

Abstract:

To study theoretically vortex state and impurity effect in the novel superconductors with triangular lattices.

Project Title:	Quantum Entanglement and Quantum Information Processing
Investigator(s):	Wang ZD
Department:	Physics
Source(s) of Funding:	Seed Funding Programme for Basic Research
Start Date:	01/2005
Completion Date:	06/2006

Abstract:

Interest in quantum entanglement and quantum information has increased dramatically in recent years because quantum entanglement plays a crucial role in quantum information processing that could solve efficiently some significant problems believed to be intractable for its classical counterpart. Moreover, quantum entanglement and quantum information processing have found their important applications in scalable solid state systems. So far, several significant progresses have been achieved in this field, including our important work on geometric quantum information processing. Nevertheless, it is both important and timely to elaborate an intrinsic connection between quantum entanglement and quantum phase transition in many-body solid state systems as well as to realize fault-tolerant quantum information processing based on scalable solid-state quantum-bits (qubits), which are two key issues in this interdisciplinary field. In this seed funding project, we shall focus on the following objectives. (1) We plan to work out a reliable and efficient approach to elaborate an intrinsic connection between many-body quantum entanglement and quantum phase transition in many-body low dimensional spin/electron systems, and to find an underline nonlocal nonclassical nature of new quantum orders in these systems. (2) We intend to develop a feasible scheme to implement fault-tolerant quantum information processing with solid state superconducting qubits coupled through a cavity and to address multi-qubit entanglement in this kind of system. (3) We attempt to study how to achieve quantum entanglement for qubits in different nodes and to transfer quantum information among relatively distant qubits. It is expected that several initial but significant results/findings will be obtained with international attentions, enabling us to attract successfully external grants to conduct further in-depth research in the field of quantum entanglement and quantum information.

Project Title:	Theoretical Studies of NaCoO Superconductors
Investigator(s):	Wang ZD, Wang Q.H.
Department:	Physics
Source(s) of Funding:	Competitive Earmarked Research Grants (CERG)
Start Date:	01/2005

Abstract:

To carry out in-depth theoretical studies on the physical quantities related to the low-lying excitation spectrum of this triangular system with emphasis on the effect of disorder to explain profoundly some existing experimental results as well as to suggest new experiments to test some predictions.

Project Title:	Theoretical Studies of NaCoO Superconductors
Investigator(s):	Wang ZD
Department:	Physics
Source(s) of Funding:	Merit Award for RGC CERG Funded Projects
Start Date:	01/2005

Abstract:

N/A

Project Title:	Interdisciplinary cutting edge research related to condensed matter physics: solid state quantum computing and quantum information processing
Investigator(s):	Wang ZD
Department:	Physics
Source(s) of Funding:	Matching Fund for NSFC Young Researcher Award
Start Date:	03/2005

Abstract:

To study interdisciplinary cutting edge research related to condensed matter physics: solid state quantum computing and quantum information processing.

Project Title:	Quantum Computation with Solid State Qubits
Investigator(s):	Wang ZD
Department:	Physics
Source(s) of Funding:	Merit Award for RGC CERG Funded Projects
Start Date:	07/2005

Abstract:

N/A

Project Title:	Quantum Computation with Solid State Qubits
Investigator(s):	Wang ZD, Zhu SL
Department:	Physics
Source(s) of Funding:	Competitive Earmarked Research Grants (CERG)
Start Date:	07/2005

Abstract:

The main objectives of this project is: (1) To develop feasible schemes to implement fault-tolerant quantum computation with superconducting and quantum-dot qubits respectively, and to compare our method with other approaches. (2) To address multi-qubit entanglement with superconducting qubits inside a cavity. (3) To study the quantum network based on superconducting qubits coupled with cavities. Very recently, a significant step towards the communication of quantum information, coherent coupling of superconducting qubits with electromagnetic modes has been experimentally demonstrated.

Project Title:	Exploring Quantum Critical Phenomena in Complex Systems
Investigator(s):	Wang ZD
Department:	Physics
Source(s) of Funding:	Seed Funding Programme for Basic Research
Start Date:	02/2006

Abstract:

Quantum entanglement, a key ingredient in quantum information science that does not have a classical counterpart, has attracted increased research interest dramatically for the past years. Recently, quantum entanglement has also been recognized to play an important role in many-body physics. In particular, it has been found to have certain interesting connection with quantum critical phenomena, which are induced by the change of coupling parameters and occur at the absolute zero temperature, in some lower dimensional correlated many-particle systems. So far, several progresses have been achieved in this field, including our work on revealing transition points in one dimensional spin systems with an entanglement entropy scenario. However, for various complex correlated many-body systems in higher dimension or with randomness, how to explore quantum critical phenomena more efficiently and reliably, which can hardly be dealt with by other methods, has been a fundamental and challenging question for a long time. Therefore, it is both important and timely to develop a systematic and model-independent approach for revealing the links between quantum entanglement entropy and quantum critical phenomena, and then to apply it for exploring in depth quantum phase transitions in a variety of correlated systems. In this seed fund project, we shall focus on the following objectives. (1) We plan to develop an efficient general approach for identifying quantum critical points in a wide class of complex correlated systems. We attempt to choose an appropriate entanglement measure to reflect the non-local nature of quantum critical phenomena in correlated lattices. This measure is designed to be an extensive quantity, like the thermal entropy in classical phase transitions, and its variation as functions of coupling parameters will be analyzed carefully, so that a clear connection between its features and quantum critical phenomena can be revealed readily. (2) We intend to investigate some realistic lattice models with randomness or doping, which can hardly be dealt with by other existing methods. Since the present entanglement scenario is expected to better capture the non-local feature of quantum critical phenomena in correlated systems, the size effect in numerical analyses is unimportant, making it be powerful and promising for the future exploration of quantum critical phenomena. It is expected that several initial but significant results/findings will be obtained with international attentions, enabling us to attract successfully external grants to conduct further in-depth research in the exploration of quantum critical phenomena.

List of Research Outputs

Researcher : Wang ZD

Project Title:	Superconductor science and technology
Investigator(s):	Wang ZD
Department:	Physics
Source(s) of Funding:	Matching Fund for National Key Basic Research Development Scheme (973 Projects)
Start Date:	02/2002

Abstract:

To carry out investigation on superconductor science and technology.

Project Title:	Quantum logic gates based on cyclic geometric phases
Investigator(s):	Wang ZD
Department:	Physics
Source(s) of Funding:	Small Project Funding
Start Date:	11/2002

Abstract:

Project Title:	Theoretical studies of impurity and vortex states in high temperature superconductors
Investigator(s):	Wang ZD
Department:	Physics
Source(s) of Funding:	Competitive Earmarked Research Grants (CERG)
Start Date:	09/2003

Abstract:

Project Title:	Theoretical studies of impurity and vortex states in high temperature superconductors
Investigator(s):	Wang ZD
Department:	Physics
Source(s) of Funding:	Merit Award for RGC CERG Funded Projects
Start Date:	09/2003

Abstract:

N/A

Project Title:	Vortex state and impurity effect in newly discovered NaCoO superconductors
Investigator(s):	Wang ZD
Department:	Physics
Source(s) of Funding:	Small Project Funding
Start Date:	11/2003

Abstract:

To study theoretically vortex state and impurity effect in the novel superconductors with triangular lattices.

Project Title:	Quantum Entanglement and Quantum Information Processing
Investigator(s):	Wang ZD
Department:	Physics
Source(s) of Funding:	Seed Funding Programme for Basic Research
Start Date:	01/2005
Completion Date:	06/2006

Abstract:

Project Title:	Theoretical Studies of NaCoO Superconductors
Investigator(s):	Wang ZD, Wang Q.H.
Department:	Physics
Source(s) of Funding:	Competitive Earmarked Research Grants (CERG)
Start Date:	01/2005

Abstract:

Project Title:	Theoretical Studies of NaCoO Superconductors
Investigator(s):	Wang ZD
Department:	Physics
Source(s) of Funding:	Merit Award for RGC CERG Funded Projects
Start Date:	01/2005

Abstract:

N/A

Project Title:	Interdisciplinary cutting edge research related to condensed matter physics: solid state quantum computing and quantum information processing
Investigator(s):	Wang ZD
Department:	Physics
Source(s) of Funding:	Matching Fund for NSFC Young Researcher Award
Start Date:	03/2005

Abstract:

To study interdisciplinary cutting edge research related to condensed matter physics: solid state quantum computing and quantum information processing.

Project Title:	Quantum Computation with Solid State Qubits
Investigator(s):	Wang ZD
Department:	Physics
Source(s) of Funding:	Merit Award for RGC CERG Funded Projects
Start Date:	07/2005

Abstract:

N/A

Project Title:	Quantum Computation with Solid State Qubits
Investigator(s):	Wang ZD, Zhu SL
Department:	Physics
Source(s) of Funding:	Competitive Earmarked Research Grants (CERG)
Start Date:	07/2005

Abstract:

Project Title:	Exploring Quantum Critical Phenomena in Complex Systems
Investigator(s):	Wang ZD
Department:	Physics
Source(s) of Funding:	Seed Funding Programme for Basic Research
Start Date:	02/2006

Abstract:

List of Research Outputs

Chen Y., Wang Z.D. and Zhang F.C., Exploring Quantum Phase Transitions with a Novel Sublattice Entanglement Scenario , The 4th International Conference on Condensed Matter Theory and Materials Computation (July 11 – 16, 2005, Chengdu, China) . 2005.

Chen Y., Wang Z.D. and Zhang F.C., Exploring quantum phase transitions with a sublattice entanglement scenario, Physical Review B. New York, The American Physical Society, 2006, 73: 224414:1-5.

Chen Y., Zanardi P., Wang Z.D. and Zhang F.C., Sublattice entanglement and quantum phase transitions in antiferromagnetic spin chains, New Journal of Physics. IOP Publishing Ltd, 2006, 8: 1-9.

He G. and Wang Z.D., Oblivious transfer using quantum entanglement, Physical Review A. New York, The American Physical Society, 2006, 73: 012331: 1-9.

He G.P. and Wang Z.D., Nonequivalence of two flavors of oblivious transfer at the quantum level, Physical Review A (Brief Reports). New York, The American Physical Society, 2006, 73: 044304: 1-4.

Li J., Zhou T. and Wang Z.D., Theoretical investigation of the quasiparticle dispersion of bilayer high-T_c superconductors, Physical Review B. New York, The American Physical Society, 2005, 72: 094515: 1-5.

Teo C.Y.J. and Wang Z.D., Geometric phase in eigenspace evolution of invariant and adiabatic action operators, Physical Review Letters. New York, The American Physical Society, 2005, 95: 050406:1-4.

Wang Q.H., Wang Z.D., Chen Y. and Zhang F.C., Unrestricted renormalized mean field theory of strongly correlated electron systems, Physical Review B (Brief Reports). New York, The American Physical Society, 2006, 73: 092507: 1-4.

Wang X. and Wang Z.D., Thermal entanglement in ferrimagnetic chains, Physical Review A (Brief Reports). New York, The American Physical Society, 2006, 73: 064302: 1-3.

Wang Y., Wang Z.D. and Sun C.P., Quantum storage and information transfer with superconducting qubits, Physical Review B (Brief Reports). New York, The American Physical Society, 2005, 72: 172507: 1-4.

Wang Z.D., Entanglement and Quantum Phase Transitions in Correlated Systems (Invited Talk), Workshop on Correlated Electron Systems, Hong Kong. 2005.

Wang Z.D., Exploring Quantum Phase Transitions with a Novel Entanglement Scenario (Invited talk), The 2005 Annual Meeting of Chinese Physical Society, Wuhan. 2005.

Wang Z.D., Geometric Phases Associated With Invariant and Adiabatic Action Operators (Invited Talk), The 4th International Workshop on Condensed Matter Theory and Computational Physics, Chengdu. 2005.

Wang Z.D., Member of Editorial Board, Frontiers of Physics: Selected Publications of China Universities. 2005.

Zhu S.L. and Wang Z.D., Geometric quantum information processing with superconducting qubits inside a cavity, Physics. Beijing, Chinese Physical Society, 2005, 34: 793-796.

Researcher : Wei Z

List of Research Outputs

Wang R., Xu S.J., Fung S.H.Y., Beling C.D., Wang K., Li S., Wei Z., Zhou T., Zhang J., Huang Y. and Gong M., Micro-Raman and photoluminescence studies of neutron-irradiated gallium nitride epilayers, Applied Physics Letters. New York, American Institute of Physics, 2005, 87: 031906:1-3.

Wang R., Xu S.J., Li S., Fung S.H.Y., Beling C.D., Wang K., Wei Z., Zhou T., Zhang J., Gong M. and Pang G.K.H., Raman scattering and X-ray diffraction study of neutron irradiated GaN epilayers, Proceeding of 2004 Conference on Optoelectronic and Microelectronic Materials and Devices, 8-10 December 2004, Australia. IEEE, 2005, 141-143.

Wei Z., Xu S.J., Duan R., Li Q., Wang J., Zeng Y.P. and Liu H.C., Thermal quenching of luminescence from buried and surface InGaAs self-assembled quantum dots with high sheet density, Journal of Applied Physics. New York, American Institute of Physics, 2005, 98: 084305: 1-4.

Researcher : Wu HS

Project Title:	Reference-selective holographic inversion of LEED spectra: a novel method to determine the final atomic structure model
Investigator(s):	Wu HS
Department:	Physics
Source(s) of Funding:	Competitive Earmarked Research Grants (CERG)
Start Date:	12/2002

Abstract:

The goal of this project is to fully explore the advantages of the direct inversions of LEED spectra and to determine the atomic structures of several interesting systems.

Project Title:	Investigation of pure cubic GaN film growth on SiC(0001) substrate
Investigator(s):	Wu HS
Department:	Physics
Source(s) of Funding:	Competitive Earmarked Research Grants (CERG)
Start Date:	12/2003

Abstract:

To investigate (1) surface structures of 6H-Sic(0001) surfaces; (2) the interface structures of GaN films/GH SiC(0001); (3) the surface structures of GaN films; (4) the growth condition dependence of the critical thickness of GaN film; (5) the driving force for cubic film growth and inversion from cubic to hexagonal; (6)the possible ways to control the critical thickness of cubic GaN film.

Project Title:	Investigation of pure cubic GaN film growth on SiC(0001) substrate
Investigator(s):	Wu HS
Department:	Physics
Source(s) of Funding:	Merit Award for RGC CERG Funded Projects
Start Date:	12/2003

Abstract:

N/A

Project Title:	Surface atomic structure extraction from low energy electron diffraction patterson function
Investigator(s):	Wu HS
Department:	Physics
Source(s) of Funding:	Seed Funding Programme for Basic Research
Start Date:	09/2004

Abstract:

A new method named structure extraction from LEED PF is fully implementing by correctly addressing the two issues; (1) a complex system often has PF spots overlap or missing, which makes structure extraction much harder; (2) real systems often have two domains or even more domains in the surface structure, which also makes structure extraction more complicated.

Project Title:	Surface Atomic structure completion from LEED Patterson Function
Investigator(s):	Wu HS
Department:	Physics
Source(s) of Funding:	Merit Award for RGC CERG Funded Projects
Start Date:	01/2005

Abstract:

N/A

Project Title:	Surface Atomic structure completion from LEED Patterson Function
Investigator(s):	Wu HS
Department:	Physics
Source(s) of Funding:	Competitive Earmarked Research Grants (CERG)
Start Date:	01/2005

Abstract:

To figure out a way to deal with unclear or unseen PF spots; to develop an approach to solve the multi-domain problems; to put the modifications into the existing computer program; to test the completed program with more samples; to apply this new method to number of interesting samples to determine their surface atomic structures.

Project Title:	Construct atomic structure models of surfaces with multiple structure phases and disordered over layers by using Low Energy Electron Diffraction Patterson Function
Investigator(s):	Wu HS
Department:	Physics
Source(s) of Funding:	Merit Award for RGC CERG Funded Projects
Start Date:	01/2006

Abstract:

N/A

Project Title:	Construct atomic structure models of surfaces with multiple structure phases and disordered over layers by using Low Energy Electron Diffraction Patterson Function
Investigator(s):	Wu HS
Department:	Physics
Source(s) of Funding:	Competitive Earmarked Research Grants (CERG)
Start Date:	01/2006

Abstract:

To determine surface structures of several GaN films and InN films grown by MBE technique in our lab. The success of these procedures will definitely enhance our capability of solving the tough problem of surface atomic structure determination.

List of Research Outputs

Liu Y., Xie M.H., Wu H.S. and Tong S.Y., Mass transport and alloying during InN growth on GaN by molecular-beam epitaxy, Applied Physics Letters. New York, American Institute of Physics, 2006, 88: 221916: 1-3.

Researcher : Wu J

List of Research Outputs

Wu J., Wang B.G., Wang J. and Guo H., Giant enhancement of dynamic conductance in molecular devices, Physical Review B. New York, The American Physical Society, 2005, 72: 195324:1-5.

Researcher : Wu X

List of Research Outputs

Qian B., Xing J.H., Wu X., Jiang S.S. and Gao J., Magnetoresistance in La- and Ca-doped YBa₂Cu₃O_7-d, Journal of Applied Physics. New York, American Institute of Physics, 2006, 99: 08M504: 1-3.

Researcher : Xia T

List of Research Outputs

Xia T., Studies of impurities and vortices in high temperature superconductors. Hong Kong, The University of Hong Kong, 2005, 1-123.

Researcher : Xie MH

Project Title:	Growth mode and strain relaxation of InGaN grown on GaN
Investigator(s):	Xie MH
Department:	Physics
Source(s) of Funding:	Competitive Earmarked Research Grants (CERG)
Start Date:	09/2002
Completion Date:	08/2005

Abstract:

The project aims at studying the growth mode, especially 3-dimensional islanding processes of InGaN grown on GaN by molecular beam epitaxy (MBE). It is designed to explore a wide range of growth parameters and to cover the whole range of In compositions of InGaN. Emphasis will be put on the underlying physics governing the growth mode.

Project Title:	Effect of excess gallium on growth kinetics of GaN
Investigator(s):	Xie MH
Department:	Physics
Source(s) of Funding:	Competitive Earmarked Research Grants (CERG)
Start Date:	09/2003
Completion Date:	08/2005

Abstract:

To study the effect of excess Ga on island nucleation kinetrics; to study the effect of excess Ga on step morphology and kinetrics.

Project Title:	Effect of excess gallium on growth kinetics of GaN
Investigator(s):	Xie MH
Department:	Physics
Source(s) of Funding:	Merit Award for RGC CERG Funded Projects
Start Date:	09/2003

Abstract:

N/A

Project Title:	Structural phase transition of InGaN epi-film during growth on (0001) surface by plasma-assisted molecular-beam epitaxy
Investigator(s):	Xie MH, Wu HS
Department:	Physics
Source(s) of Funding:	Competitive Earmarked Research Grants (CERG)
Start Date:	09/2004

Abstract:

To investigate the structural phases of epitaxial InN and GaN films; to examine the possible dependence of crystal structure of the epi-film on the MBE condition; to investigate the physical origin of such a growth phenomenon.

Project Title:	Structural phase transition of InGaN epi-film during growth on (0001) surface by plasma-assisted molecular-beam epitaxy
Investigator(s):	Xie MH
Department:	Physics
Source(s) of Funding:	Merit Award for RGC CERG Funded Projects
Start Date:	01/2005

Abstract:

N/A

Project Title:	Anomalous temperature dependence of the growth mode and strain in InN/GaN during molecular-beam epitaxy
Investigator(s):	Xie MH
Department:	Physics
Source(s) of Funding:	Merit Award for RGC CERG Funded Projects
Start Date:	09/2005

Abstract:

N/A

Project Title:	Anomalous temperature dependence of the growth mode and strain in InN/GaN during molecular-beam epitaxy
Investigator(s):	Xie MH
Department:	Physics
Source(s) of Funding:	Competitive Earmarked Research Grants (CERG)
Start Date:	09/2005

Abstract:

The project aims at understanding the followings: 1. Alloying between InN and GaN at the heterointerface. In the Stranski-Krastanov (SK) growth of InN on GaN, we shall follow the evolution of volume of the SK-islands under different growth conditions. Comparing to the amount deposited from the flux, I hope that mass transfer from SK-wetting layer and/or GaN substrate to the islands may be established and thereby the extend of alloying at InN/GaN heterointerface be revealed; 2. Effect of surface excess indium layer. Comparion will be made between growth under excess indium and excess nitrogen conditions, so that the effect of surface excess indium adlayer(s) may be noted; 3. Defects in heteroepitaxial InN. The character and density of defects in heteroepitaxial InN layers will be measured, which will be correlated to the state of strain in film.

List of Research Outputs

Cai X., Djurisic A., Xie M.H., Chiu C.S. and Gwo S., Growth mechanism of stacked-cone and smooth-surface GaN nanowires, Applied Physics Letters. New York, American Institute of Physics, 2005, 87: 183103: 1-3.

Cai X., Djurisic A. and Xie M.H., Growth of SiO_x nanowire bunches cocatalyzed with Ga and Ni, Journal of Applied Physics. New York, American Institute of Physics, 2005, 98: 074313:1-5.

Cai X., Cheng K.W., Oey C.C., Djurisic A., Chan W.K., Xie M.H. and Chui P.C., Porous metallic films fabricated by self-assembly of gold nanoparticles, Thin Solid Films. Amsterdam, Elsevier B.V., 2005, 491: 66-70.

Cai X., Leung Y.H., Cheung K.Y., Tam K.H., Djurisic A., Xie M.H., Chen H.Y. and Gwo S., Straight and helical InGaN core-shell nanowires with a high In core content, Nanotechnology. Bristol, IOP Publishing Limited, 2006, 17: 2330-2333.

Dai D., Xu S.J., Shi S., Xie M.H. and Che C.M., Efficient multiphoton-absorption-induced luminescence in single-crystalline ZnO at room temperature, Optics Letters. Washington, Optical Society of America, 2005, 30: 3377-3379.

Dai X.Q., Ju W.W., Xie M.H. and Tong S.Y., Ab initio study of indium quantum wire formation on flat and stepped Si(100) surfaces, Surface Review and Letters. Singapore, World Scientific, 2005, 12: 483-487.

Djurisic A., Wang H., Chan W.K. and Xie M.H., Characterization of block copolymers using scanning probe microscopy, Journal of Scanning Probe Microscopy. American Scientific Publishers, 2006, 1: 21-31.

Djurisic A., Kwok W.M., Chan W.K., Phillips D.L., Leung Y.H., Xie M.H., Chen H.Y., Wu C.L. and Gwo S., Optical properties of highly faceted ZnO rods, Journal of Applied Physics. New York, American Institute of Physics, 2006, 99: 033517: 1-6.

Kwok W.M., Djurisic A., Leung Y.H., Chan W.K., Phillips D.L., Chen H.Y., Wu C.L., Gwo S. and Xie M.H., Study of excitonic emission in highly faceted ZnO rods, Chemical Physics Letters. Amsterdam, Elsevier B.V., 2005, 412: 141-144.

Leung Y.H., Djurisic A. and Xie M.H., Non-catalytic synthesis of ZnO nanocolumns with different cross-sections, Journal of Crystal Growth. Amsterdam, Elsevier B.V., 2005, 284: 80-85.

Leung Y.H., Tam K.H., Djurisic A., Xie M.H., Chan W.K., Lu D. and Ge W.K., ZnO nanoshells: synthesis, structure, and optical properties, Journal of Crystal Growth. Amsterdam, Elsevier B.V., 2005, 283: 134-140.

Li D., Leung Y.H., Djurisic A., Liu Z., Xie M.H., Gao J. and Chan W.K., CuO nanostructures prepared by a chemical method, Journal of Crystal Growth. Amsterdam, Elsevier B.V., 2005, 282: 105-111.

Li Q., Xu S.J., Xie M.H. and Tong D.S.Y., A model for steady-state luminescence of localized-state ensemble, Europhysics Letters. EDP Sciences, 2005, 71: 994-1000.

Li Q., Xu S.J., Xie M.H. and Tong D.S.Y., Origin of the `S-shaped' temperature dependence of luminescent peaks from semiconductors, Journal of Physics: Condensed Matter. Bristol, Institute of Physics Publishing, 2005, 17: 4853-4858.

Liu Y., Xie M.H., Wu H.S. and Tong S.Y., Mass transport and alloying during InN growth on GaN by molecular-beam epitaxy, Applied Physics Letters. New York, American Institute of Physics, 2006, 88: 221916: 1-3.

Oey C.C., Djurisic A., Wang H., Man K.K.Y., Chan W.K., Xie M.H., Leung Y.H., Pandey A., Nunzi J.M. and Chui P.C., Polymer-TiO₂ solar cells: TiO₂ interconnected network for improved cell performance, Nanotechnology. Bristol, IOP Publishing Limited, 2006, 17: 706-713.

Wang H., Djurisic A., Chan W.K. and Xie M.H., Factors affecting phase and height contrast of diblock copolymer PS-b-PEO thin films in dynamic force mode atomic force microscopy, Applied Surface Science. Amsterdam, Elsevier B.V., 2005, 252: 1092-1100.

Wang H., Djurisic A., Xie M.H., Chan W.K. and Kutsay O., Morphology evolution of an asymmetric diblock copolymer P(S-b-MMA) as a function of film thickness and annealing time, International Journal of Nanoscience. Singapore, World Scientific, 2005, 4: 737-743.

Wang H., Djurisic A., Xie M.H., Chan W.K. and Kutsay O., Perpendicular domains in poly(styrene-b-methyl methacrylate) block copolymer films on preferential surfaces, Thin Solid Films. Amsterdam, Elsevier B.V., 2005, 488: 329-336.

Wang H., Oey C.C., Djurisic A., Xie M.H., Leung Y.H., Man K.K.Y., Chan W.K., Pandey A., Nunzi J.M. and Chui P.C., Titania bicontinuous network structures for solar cell applications, Applied Physics Letters. New York, American Institute of Physics, 2005, 87: 023507:1-3.

Researcher : Xiong S

List of Research Outputs

Xiong S. and Xu S.J., Phonon coherence and new set of sidebands in phonon-assisted photoluminescence, Europhysics Letters. EDP Sciences, 2005, 71: 459-465.

Xu S.J., Xiong S., Liu J. and Zheng H.Z., New type of Fano resonant tunneling via Anderson impurities in superlattice, Europhysics Letters. EDP Sciences, 2006, 74: 875-881.

Xu S.J., Xiong S. and Shi S., Resonant coupling of bound excitons with LO phonons in ZnO: Excitonic polaron states and Fano interference, The Journal of Chemical Physics. New York, American Institute of Physics, 2005, 123: 221105: 1-5.

Xu S.J., Li G., Xiong S. and Che C.M., Temperature dependence of the LO phonon sidebands in free exciton emission of GaN, Journal of Applied Physics. New York, American Institute of Physics, 2006, 99: 073508: 1-5.

Researcher : Xu S

Project Title:	Comprehensive spectroscopy investigations of blue and green InGaN/GaN light-emitting diode structures with multi-quantum-wells
Investigator(s):	Xu SJ
Department:	Physics
Source(s) of Funding:	Competitive Earmarked Research Grants (CERG)
Start Date:	09/2003

Abstract:

The main objective of this project is to understand the luminescence mechanism in the InGaN/GaN LEDs with quantum wells (QWs).

Project Title:	Comprehensive spectroscopy investigations of blue and green InGaN/GaN light-emitting diode structures with multi-quantum-wells
Investigator(s):	Xu SJ
Department:	Physics
Source(s) of Funding:	Merit Award for RGC CERG Funded Projects
Start Date:	09/2003

Abstract:

N/A

Project Title:	Optical characterization of cubic phase GaN epilayers grown 6H-SiC substrates
Investigator(s):	Xu SJ, Wu HS
Department:	Physics
Source(s) of Funding:	Seed Funding Programme for Basic Research
Start Date:	04/2004
Completion Date:	03/2006

Abstract:

To investigate optical properties of the cubic phase GaN grown on 6H-SiC. Optical characterization of the available samples and new samples to be grown is major task of the proposed research.

Project Title:	Multiphoton excited photoluminescence and coherent spectra in wide gap semiconductors
Investigator(s):	Xu SJ
Department:	Physics
Source(s) of Funding:	Small Project Funding
Start Date:	11/2004
Completion Date:	04/2006

Abstract:

To investigate two-and three-photon excited photoluminescence and coherent spectra of carriers in ZnO and Gan etc. wide band gap semiconductors.

Project Title:	Optical Properties and Electronic Structures of InGaAs/GaAs Self-Assembled Quantum Dots with High Sheet Density
Investigator(s):	Xu SJ
Department:	Physics
Source(s) of Funding:	Merit Award for RGC CERG Funded Projects
Start Date:	01/2005

Abstract:

N/A

Project Title:	Optical Properties and Electronic Structures of InGaAs/GaAs Self-Assembled Quantum Dots with High Sheet Density
Investigator(s):	Xu SJ
Department:	Physics
Source(s) of Funding:	Competitive Earmarked Research Grants (CERG)
Start Date:	01/2005

Abstract:

To gain understanding of the optical properties and electronic structures of high sheet density InGaAs/GaAs self-assembled quantum dots (QDs) through detailed experimental and theoretical investigations.

Project Title:	Phonon-Mediated Fano Resonance in LO Phonon-Assisted Luminescence of Bound Excitons in Wide Gap Polar Semiconductors
Investigator(s):	Xu SJ
Department:	Physics
Source(s) of Funding:	Incentive Award for RGC CERG Fundable But Not Funded Projects
Start Date:	07/2005
Completion Date:	06/2006

Abstract:

N/A

List of Research Outputs

Researcher : Xu SJ

Project Title:	Comprehensive spectroscopy investigations of blue and green InGaN/GaN light-emitting diode structures with multi-quantum-wells
Investigator(s):	Xu SJ
Department:	Physics
Source(s) of Funding:	Competitive Earmarked Research Grants (CERG)
Start Date:	09/2003

Abstract:

The main objective of this project is to understand the luminescence mechanism in the InGaN/GaN LEDs with quantum wells (QWs).

Project Title:	Comprehensive spectroscopy investigations of blue and green InGaN/GaN light-emitting diode structures with multi-quantum-wells
Investigator(s):	Xu SJ
Department:	Physics
Source(s) of Funding:	Merit Award for RGC CERG Funded Projects
Start Date:	09/2003

Abstract:

N/A

Project Title:	Optical characterization of cubic phase GaN epilayers grown 6H-SiC substrates
Investigator(s):	Xu SJ, Wu HS
Department:	Physics
Source(s) of Funding:	Seed Funding Programme for Basic Research
Start Date:	04/2004
Completion Date:	03/2006

Abstract:

To investigate optical properties of the cubic phase GaN grown on 6H-SiC. Optical characterization of the available samples and new samples to be grown is major task of the proposed research.

Project Title:	Multiphoton excited photoluminescence and coherent spectra in wide gap semiconductors
Investigator(s):	Xu SJ
Department:	Physics
Source(s) of Funding:	Small Project Funding
Start Date:	11/2004
Completion Date:	04/2006

Abstract:

To investigate two-and three-photon excited photoluminescence and coherent spectra of carriers in ZnO and Gan etc. wide band gap semiconductors.

Project Title:	Optical Properties and Electronic Structures of InGaAs/GaAs Self-Assembled Quantum Dots with High Sheet Density
Investigator(s):	Xu SJ
Department:	Physics
Source(s) of Funding:	Merit Award for RGC CERG Funded Projects
Start Date:	01/2005

Abstract:

N/A

Project Title:	Optical Properties and Electronic Structures of InGaAs/GaAs Self-Assembled Quantum Dots with High Sheet Density
Investigator(s):	Xu SJ
Department:	Physics
Source(s) of Funding:	Competitive Earmarked Research Grants (CERG)
Start Date:	01/2005

Abstract:

Project Title:	Phonon-Mediated Fano Resonance in LO Phonon-Assisted Luminescence of Bound Excitons in Wide Gap Polar Semiconductors
Investigator(s):	Xu SJ
Department:	Physics
Source(s) of Funding:	Incentive Award for RGC CERG Fundable But Not Funded Projects
Start Date:	07/2005
Completion Date:	06/2006

Abstract:

N/A

List of Research Outputs

Dai D., Xu S.J., Shi S., Xie M.H. and Che C.M., Efficient multiphoton-absorption-induced luminescence in single-crystalline ZnO at room temperature, Optics Letters. Washington, Optical Society of America, 2005, 30: 3377-3379.

Li Q., Xu S.J., Xie M.H. and Tong D.S.Y., A model for steady-state luminescence of localized-state ensemble, Europhysics Letters. EDP Sciences, 2005, 71: 994-1000.

Li Q., Xu S.J., Xie M.H. and Tong D.S.Y., Origin of the `S-shaped' temperature dependence of luminescent peaks from semiconductors, Journal of Physics: Condensed Matter. Bristol, Institute of Physics Publishing, 2005, 17: 4853-4858.

Li Q., Xu S.J., Dai D. and Che C.M., Two-photon excited photoluminescence in InGaN multi-quantum-wells structures, Proceeding of 2004 Conference on Optoelectronic and Microelectronic Materials and Devices, 8-10 December 2004, Australia. IEEE, 2005, 153-155.

Shi S., Li G., Xu S.J., Zhao Y. and Chen G., Green luminescence band in ZnO: Fine structures, electron-phonon coupling, and temperature effect, Journal of Physical Chemistry B. American Chemical Society, 2006, 110: 10475-10478.

Shi S., Xu S.J., Wang X. and Chen G., Theoretical absorption spectra of silicon carbide nanocrystals, Thin Solid Films. Amsterdam, Elsevier B.V., 2006, 495: 404-406.

Wang R., Xu S.J., Fung S.H.Y., Beling C.D., Wang K., Li S., Wei Z., Zhou T., Zhang J., Huang Y. and Gong M., Micro-Raman and photoluminescence studies of neutron-irradiated gallium nitride epilayers, Applied Physics Letters. New York, American Institute of Physics, 2005, 87: 031906:1-3.

Wang R., Xu S.J., Li S., Fung S.H.Y., Beling C.D., Wang K., Wei Z., Zhou T., Zhang J., Gong M. and Pang G.K.H., Raman scattering and X-ray diffraction study of neutron irradiated GaN epilayers, Proceeding of 2004 Conference on Optoelectronic and Microelectronic Materials and Devices, 8-10 December 2004, Australia. IEEE, 2005, 141-143.

Wang Y., Xu S.J. and Li Q., Anisotropic ambipolar diffusion of carriers in InGaN/GaN quantum wells, Physica Status Solidi C. Weinheim, WILEY-VCH Verlag GmbH & Co., 2006, 3: 1988-1991.

Wang Y., Xu S.J., Li Q., Zhao D.G. and Yang H., Band gap renormalization and carrier localization effects in InGaN/GaN quantum-wells light emitting diodes with Si doped barriers, Applied Physics Letters. New York, American Institute of Physics, 2006, 88: 041903: 1-3.

Wei Z., Xu S.J., Duan R., Li Q., Wang J., Zeng Y.P. and Liu H.C., Thermal quenching of luminescence from buried and surface InGaAs self-assembled quantum dots with high sheet density, Journal of Applied Physics. New York, American Institute of Physics, 2005, 98: 084305: 1-4.

Xiong S. and Xu S.J., Phonon coherence and new set of sidebands in phonon-assisted photoluminescence, Europhysics Letters. EDP Sciences, 2005, 71: 459-465.

Xu S.J., Fano Resonance in Phonon-Assisted Photoluminescence Spectra of Widegap Polar Semiconductors, 20th Congress of the International Commission for Optics. 2005.

Xu S.J., Xiong S.J., Shi S. and Jin K.J., Fano resonance in phonon-assisted photoluminescence spectra of wide gap polar semiconductors, 20th Congress of the International Commission for Optics. CD-ROM, 2005, 6029: 0600-08.

Xu S.J., Fs-Multi-Photon-Excited Fluorescence and Carrier Dynamics in ZnO, 4th Asia Conference on Ultrafast Phenomena. 2006.

Xu S.J., Xiong S., Liu J. and Zheng H.Z., New type of Fano resonant tunneling via Anderson impurities in superlattice, Europhysics Letters. EDP Sciences, 2006, 74: 875-881.

Xu S.J., On The Luminescence Of Localized-state Ensemble, the Annual Meeting of Chinese Physics Society 2005. 2005.

Xu S.J., Li G., Wang Y., Zhao Y., Chen G., Zhao D.G., Zhu J.J., Yang H., Yu D.P. and Wang J.N., Quantum dissipation and broadening mechanisms due to electron-phonon interactions in self-formed InGaN quantum dots, Applied Physics Letters. New York, American Institute of Physics, 2006, 88: 083123: 1-3.

Xu S.J., Xiong S. and Shi S., Resonant coupling of bound excitons with LO phonons in ZnO: Excitonic polaron states and Fano interference, The Journal of Chemical Physics. New York, American Institute of Physics, 2005, 123: 221105: 1-5.

Xu S.J., Li G., Xiong S. and Che C.M., Temperature dependence of the LO phonon sidebands in free exciton emission of GaN, Journal of Applied Physics. New York, American Institute of Physics, 2006, 99: 073508: 1-5.

Xu S.J., Two-Photon Absorption Induced Luminescence and Carrier Dynamics in InGaN/GaN Quantum Well Structures, HKU-ICCAS Workshop on Molecular Functional Materials. 2005.

Xu Y., Wang J. and Xu S.J., Quantum transport through C₄₈N₁₂ based atomic devices, The Journal of Chemical Physics. New York, American Institute of Physics, 2006, 124: 114702:1-6.

Yang H., Xu S.J., Li Q. and Zhang J., Resonantly enhanced femtosecond second-harmonic generation and nonlinear luminescence in GaN film grown on sapphire, Applied Physics Letters. New York, American Institute of Physics, 2006, 88: 161113: 1-3.

Zhong Z.Q., Wu D.X., Gong M., Wang O., Shi S., Xu S.J., Chen X., Ling F.C.C., Fung S.H.Y., Beling C.D., Brauer G., Anwand W. and Skorupa W., Primary photoluminescence in as-neutron (electron) –irradiated n-type 6H-SiC, Journal of Applied Physics. New York, American Institute of Physics, 2006, 99: 093511: 1-3.

Researcher : Xu Y

List of Research Outputs

Xu Y., Wang J. and Xu S.J., Quantum transport through C₄₈N₁₂ based atomic devices, The Journal of Chemical Physics. New York, American Institute of Physics, 2006, 124: 114702:1-6.

Researcher : Yang H

List of Research Outputs

Yang H., Xu S.J., Li Q. and Zhang J., Resonantly enhanced femtosecond second-harmonic generation and nonlinear luminescence in GaN film grown on sapphire, Applied Physics Letters. New York, American Institute of Physics, 2006, 88: 161113: 1-3.

Researcher : Yang K

List of Research Outputs

Yang K., Shih C.T., Chou C.P., Huang S.M., Lee T.K., Xiang T. and Zhang F.C., Low-energy physical properties of high-T_c superconducting Cu oxides: A comparison between the resonating valence bond and experiments, Physical Review B. New York, The American Physical Society, 2006, 73: 224513:1-12.

Yang K., Rice T.M. and Zhang F.C., Phenomenological theory of the pseudogap state, Physical Review B. New York, The American Physical Society, 2006, 73: 174501: 1-10.

Researcher : Yao H

List of Research Outputs

Gao J., Hu F. and Yao H., Impact of electric currents on the insulator-metal phase transition in epitaxial thin films of La_1-xA_xMnO₃ (A = Sr, Ca, and Ba), Applied Surface Science. Amsterdam, Elsevier B.V., 2006, 252: 5521-5524.

Yao H., Hu F. and Gao J., Strain effect and current-induced electroresistance in epitaxial thin films of La_0.9Sr_0.1MnO₃, Thin Solid Films. Amsterdam, Elsevier B.V., 2006, 495: 165-168.

Yao H., Study of the giant electroresistance in epitaxial thin films of La_0.9Sr_0.1MnO₃. Hong Kong, The University of Hong Kong, 2005, 1-88.

Researcher : Yiu WC

List of Research Outputs

Yiu W.C., Synthesis of one-dimensional Tungsten oxide nano-structures by thermal evaporation. Hong Kong, The University of Hong Kong, 2005, 1-53.

Researcher : Young CK

List of Research Outputs

Wu H., Cao C., Hao C.N., Liu F.S., Wang J.L., Xia X.Y., Deng Z.G. and Young C.K., PAH and mid-infrared luminosities as measures of star formation rate in Spitzer first look survey galaxies, The Astrophysical Journal. The American Astronomical Society, 2005, 632: L79-L82.

Researcher : Zhang F

Project Title:	Superconductor and antiferromagnetic insulator transition in cuprates and layered organic superconductors
Investigator(s):	Zhang FC
Department:	Physics
Source(s) of Funding:	Merit Award for RGC CERG Funded Projects
Start Date:	01/2005

Abstract:

N/A

Project Title:	Superconductor and antiferromagnetic insulator transition in cuprates and layered organic superconductors
Investigator(s):	Zhang FC
Department:	Physics
Source(s) of Funding:	Competitive Earmarked Research Grants (CERG)
Start Date:	01/2005

Abstract:

To gain theoretical understanding of a class of superconductors on the verge of antiferromagnetic insulators. The key issue is to investigate the completition between the electron localization due to electron-electron repulsive force and the delocalized paired electrons due to electron's kinetic energy and the attractive force between electrons originated from the antiferromagnetic spin-spin coupling.

Project Title:	Proposal for Seed Funding for Strategic Research Theme - Computational Physics and Numerical Methods
Investigator(s):	Zhang FC, Cheung PYS, Ching WK, Mok N, Chwang ATY, Sze KY
Department:	Physics
Source(s) of Funding:	Seed Funding for Strategic Research Theme
Start Date:	07/2005

Abstract:

The proposed theme focuses on the computational physics and relevant numerical methodologies, and concentrates the research activities that are of interests to both Faculty of Science and Faculty of Engineering. It includes both the development of the methods and the applications. We intend to develop quantum mechanical methods for complex systems, optimiation techniques such as nonlinear programming, data mining convex programming, and general numerical methods including finite element techniques, large-dimension matrix manipulation and iterative procedures. Using these novel numberical methods together with the existing ones, we would investigate the topics in nano-optics, electrics, transport and mechanics and would also be interested in examine phenomena at larger scales such as structural analysis of continuum systems, soil mechanics, fluid mechanics, crack, fracture and multi-physics problems.

Project Title:	Theory of tunneling conductance and possible checkerboard charge ordering in high temperature superconducting copper oxides
Investigator(s):	Zhang FC
Department:	Physics
Source(s) of Funding:	Merit Award for RGC CERG Funded Projects
Start Date:	08/2005

Abstract:

N/A

Project Title:	Theory of tunneling conductance and possible checkerboard charge ordering in high temperature superconducting copper oxides
Investigator(s):	Zhang FC
Department:	Physics
Source(s) of Funding:	Competitive Earmarked Research Grants (CERG)
Start Date:	08/2005

Abstract:

The main objective of this project is to gain theoretical understanding of the checkerboard like electron charge ordering observed in recent scanning tunneling microscopy measurements in high critical temperature (high Tc) superconducting copper oxides.

Project Title:	Exploring novel electronic states in condensed matter
Investigator(s):	Zhang FC, Lin HQ, Ng TK, Tang LH, Wang ZD
Department:	Physics
Source(s) of Funding:	Central Allocation Vote - Group Research Project
Start Date:	03/2006

Abstract:

To explore mechanisms that lead to the novel electronic states in condensed matter materials and to develop theories that quantify their physical properties; to explore the intrinsic relation between entanglement and quantum phase transitions; to form a multi-institutional research center in theoretical and computational physics.

List of Research Outputs

Researcher : Zhang FC

Project Title:	Superconductor and antiferromagnetic insulator transition in cuprates and layered organic superconductors
Investigator(s):	Zhang FC
Department:	Physics
Source(s) of Funding:	Merit Award for RGC CERG Funded Projects
Start Date:	01/2005

Abstract:

N/A

Project Title:	Superconductor and antiferromagnetic insulator transition in cuprates and layered organic superconductors
Investigator(s):	Zhang FC
Department:	Physics
Source(s) of Funding:	Competitive Earmarked Research Grants (CERG)
Start Date:	01/2005

Abstract:

Project Title:	Proposal for Seed Funding for Strategic Research Theme - Computational Physics and Numerical Methods
Investigator(s):	Zhang FC, Cheung PYS, Ching WK, Mok N, Chwang ATY, Sze KY
Department:	Physics
Source(s) of Funding:	Seed Funding for Strategic Research Theme
Start Date:	07/2005

Abstract:

Project Title:	Theory of tunneling conductance and possible checkerboard charge ordering in high temperature superconducting copper oxides
Investigator(s):	Zhang FC
Department:	Physics
Source(s) of Funding:	Merit Award for RGC CERG Funded Projects
Start Date:	08/2005

Abstract:

N/A

Project Title:	Theory of tunneling conductance and possible checkerboard charge ordering in high temperature superconducting copper oxides
Investigator(s):	Zhang FC
Department:	Physics
Source(s) of Funding:	Competitive Earmarked Research Grants (CERG)
Start Date:	08/2005

Abstract:

Project Title:	Exploring novel electronic states in condensed matter
Investigator(s):	Zhang FC, Lin HQ, Ng TK, Tang LH, Wang ZD
Department:	Physics
Source(s) of Funding:	Central Allocation Vote - Group Research Project
Start Date:	03/2006

Abstract:

List of Research Outputs

Bao Y., Zhuang H., Shen S.Q. and Zhang F.C., Edge spin current and spin polarization in quantum Hall regime, Physical Review B. New York, The American Physical Society, 2005, 72: 245323:1-5.

Chen Y., Wang Z.D. and Zhang F.C., Exploring Quantum Phase Transitions with a Novel Sublattice Entanglement Scenario , The 4th International Conference on Condensed Matter Theory and Materials Computation (July 11 – 16, 2005, Chengdu, China) . 2005.

Chen Y., Wang Z.D. and Zhang F.C., Exploring quantum phase transitions with a sublattice entanglement scenario, Physical Review B. New York, The American Physical Society, 2006, 73: 224414:1-5.

Chen Y., Zanardi P., Wang Z.D. and Zhang F.C., Sublattice entanglement and quantum phase transitions in antiferromagnetic spin chains, New Journal of Physics. IOP Publishing Ltd, 2006, 8: 1-9.

Dai X., Fang Z., Yao Y.G. and Zhang F.C., Resonant intrinsic spin Hall effect in p-type GaAs quantum well structure, Physical Review Letters. New York, The American Physical Society, 2006, 96: 086802: 1-4.

Dai X., Ma M. and Zhang F.C., Theory for supersolid ⁴He: Vacancy condensation facilitated by a low-energy bound state of a vacancy and an interstitial, Physical Review B (Brief Reports). New York, The American Physical Society, 2005, 72: 132504: 1-4.

Gan J.Y., Chen Y., Su Z.B. and Zhang F.C., Gossamer superconductivity in layered organic compounds K-(BEDT-TTF)₂X, Progress of Theoretical Physics Supplement. Japan, 2005, 15-27.

Jin P.Q., Li Y.Q. and Zhang F.C., SU(2) x U(1) unified theory for charge, orbit and spin currents, Journal of Physics A: Mathematical and General. Bristol, IOP Publishing Limited, 2006, 39: 7115-7123.

Li J., Dai X., Shen S.Q. and Zhang F.C., Transverse electric current induced by optically injected spin current in a cross-shaped InGaAs/InAlAs system, Applied Physics Letters. New York, American Institute of Physics, 2006, 88: 162105: 1-3.

Li T., Wang Q.H., Weng Z.Y., Yang F. and Zhang F.C., Local antiferromagnetic moment induced by Zn impurity in high-T_c superconducting copper oxides: A resonating-valence-bond picture, Physical Review B (Brief Reports). New York, The American Physical Society, 2006, 73: 212504:1-4.

Randeria M., Sensarma R., Trivedi N. and Zhang F.C., Particle-hole asymmetry in doped Mott insulators: Implications for tunneling and photoemission spectroscopies, Physical Review Letters. New York, The American Physical Society, 2005, 95: 137001: 1-4.

Wang Q.H., Wang Z.D., Chen Y. and Zhang F.C., Unrestricted renormalized mean field theory of strongly correlated electron systems, Physical Review B (Brief Reports). New York, The American Physical Society, 2006, 73: 092507: 1-4.

Yang K., Shih C.T., Chou C.P., Huang S.M., Lee T.K., Xiang T. and Zhang F.C., Low-energy physical properties of high-T_c superconducting Cu oxides: A comparison between the resonating valence bond and experiments, Physical Review B. New York, The American Physical Society, 2006, 73: 224513:1-12.

Yang K., Rice T.M. and Zhang F.C., Phenomenological theory of the pseudogap state, Physical Review B. New York, The American Physical Society, 2006, 73: 174501: 1-10.

Researcher : Zhang J

List of Research Outputs

Beling C.D., Ling F.C.C., Cheung C.K., Naik P.S., Zhang J. and Fung S.H.Y., Positron beam studies of transients in semiconductors, Applied Surface Science. Amsterdam, Elsevier B.V., 2006, 252: 3172-3182.

Li S., Zhang J., Beling C.D., Wang K., Wang R., Gong M. and Sarkar C.K., Large lattice relaxation deep levels in neutron-irradiated GaN, Journal of Applied Physics. New York, American Institute of Physics, 2005, 98: 093517: 1-6.

Wang R., Xu S.J., Fung S.H.Y., Beling C.D., Wang K., Li S., Wei Z., Zhou T., Zhang J., Huang Y. and Gong M., Micro-Raman and photoluminescence studies of neutron-irradiated gallium nitride epilayers, Applied Physics Letters. New York, American Institute of Physics, 2005, 87: 031906:1-3.

Wang R., Xu S.J., Li S., Fung S.H.Y., Beling C.D., Wang K., Wei Z., Zhou T., Zhang J., Gong M. and Pang G.K.H., Raman scattering and X-ray diffraction study of neutron irradiated GaN epilayers, Proceeding of 2004 Conference on Optoelectronic and Microelectronic Materials and Devices, 8-10 December 2004, Australia. IEEE, 2005, 141-143.

Zhang J., Zhou T., Cheung C.K., Beling C.D., Fung S.H.Y. and Ng M.K., Deconvolution of 2D coincident Doppler broadening spectroscopy using the Richardson-Lucy algorithm, Nuclear Instruments and Methods in Physics Research A. Amsterdam, Elsevier B.V., 2006, 560: 552-557.

Researcher : Zhao H

List of Research Outputs

Zhao H., Wang J. and Wang Q., Charge and spin currents tunnelling through a toroidal carbon nanotube side-coupled with a quantum dot, European Physical Journal B. EDP Sciences, 2006, 51: 425-433.

Researcher : Zhou B

List of Research Outputs

Zhou B., Ren L. and Shen S.Q., Spin transverse force and intrinsic quantum transverse transport, Physical Review B. New York, The American Physical Society, 2006, 73: 165303:1-7.

Researcher : Zhou T

List of Research Outputs

Wang R., Xu S.J., Fung S.H.Y., Beling C.D., Wang K., Li S., Wei Z., Zhou T., Zhang J., Huang Y. and Gong M., Micro-Raman and photoluminescence studies of neutron-irradiated gallium nitride epilayers, Applied Physics Letters. New York, American Institute of Physics, 2005, 87: 031906:1-3.

Wang R., Xu S.J., Li S., Fung S.H.Y., Beling C.D., Wang K., Wei Z., Zhou T., Zhang J., Gong M. and Pang G.K.H., Raman scattering and X-ray diffraction study of neutron irradiated GaN epilayers, Proceeding of 2004 Conference on Optoelectronic and Microelectronic Materials and Devices, 8-10 December 2004, Australia. IEEE, 2005, 141-143.

Zhang J., Zhou T., Cheung C.K., Beling C.D., Fung S.H.Y. and Ng M.K., Deconvolution of 2D coincident Doppler broadening spectroscopy using the Richardson-Lucy algorithm, Nuclear Instruments and Methods in Physics Research A. Amsterdam, Elsevier B.V., 2006, 560: 552-557.

Researcher : Zhu Y

Project Title:	Magnetism and Magneto-resistance in Carbon Nanotube / Transition Metal Hybrid System
Investigator(s):	Zhu Y
Department:	Physics
Source(s) of Funding:	Seed Funding Programme for Basic Research
Start Date:	06/2006

Abstract:

Spintronics aims at using the spin of electrons to carry information [1]. The simplest spintronics device is spin-valve, which consists of two ferromagnetic electrodes sandwiched with a layer of nonmagnetic metal or insulator. The junction resistance can be manipulated with a relative small magnetic field due to spin polarization at the Fermi energy. Transition metals are widely used to grow magnetic thin films and fabricate spin-valve. On the other hand, one-dimensional nano-devices are desirable in some application circumstances. Especially, carbon nanotubes are well studied for their physical properties and show great potential as building blocks in nanoscale electronics [2]. Experimentally, carbon nanotubes can either be filled with materials in its cavity or be coated with materials on the tube surface [3,4]. A combination of carbon nanotubes and ferromagnetic transition metals could be promising in providing the required magnetism, dimensionality, and small volume. Transport measurements on multi-wall carbon nanotubes coupled to ferromagnetic electrodes showed maximum magneto-resistance of 9%, from which the spin-flip scattering length is estimated to be at least 130 nm [5]. Pronounced gate-field-controlled magneto-resistance was observed in carbon nanotubes connected by ferromagnetic leads. Both the magnitude and the sign of the magneto-resitance can be tuned with gate voltages [6]. However, there are only a few theoretical works for the properties of carbon nanotube / transition metal hybrid systems [7,8]. Very recently, Yang et al found through ab initio calculation that ferromagnetic materials packed inside carbon nanotubes exhibit substantial magnetism and strong spin polarization at the Fermi level [8]. Motivated by their work, we propose to study the transport properties in the magnetic junctions composed of carbon nanotube and transition metals. The objective of this project is summarized as follows: (1) Develop and apply the new version of matdcal package to model spin-dependent transport. The new version adopts k point sampling in the xy-plane to simulate multi-layer structures; Both local spin density approximation (LSDA) and generalized gradient approximation (GGA) are implemented in the exchange correlation energy; partial core correction and optimized Siesta orbitals are used in the calculation. (2) Investigate the magnetism of quasi 1D ferromagnetic wire and its effects on the magneto-resistance. Several questions are to be answered: How does the magnetism evolves from 3D bulk to quasi 1D wire? How does the coupling between carbon nanotube and ferromagnetic atoms change the magnetism? What is the magneto-resistance in some possible geometries (e.g., carbon nanotube filled or coated with cobalt atoms)? Whether the singularity in density of states of 1D system enhances the spin polarization at the Fermi level? [1] G. A. Prinz. Cience 282, 1660 (1998). [2] M. S. Dresselhaus, G. Dresselhaus, and P. Avouris, Carbon Nanotubes: Synthesis, Structure, Properties and Applications (Springer-Verlag, Berlin, Germany, 2001). [3] M. Monthious, Carbon 40, 1809 (2002). [4] Y. Zhang and H. Dai, Appl. Phys. Lett. 77, 3015 (2000). [5] K. Tsukagoshi, B. W. Alphenaar, and H. Ago, Nature (London) 401, 572 (1999). [6] S. Sahoo et al, Nature Physics 1, 99 (2005). [7] H. Mehrez, J. Taylor, H. Guo, J. Wang, and C. Roland, Phys. Rev. Lett. 84, 2682 (2000). [8] C.-K. Yang, J. Zhao, and J. P. Lu, Phys. Rev. Lett. 90, 257203 (2003).

List of Research Outputs

Researcher : Zhuang H

List of Research Outputs

Bao Y., Zhuang H., Shen S.Q. and Zhang F.C., Edge spin current and spin polarization in quantum Hall regime, Physical Review B. New York, The American Physical Society, 2005, 72: 245323:1-5.

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