- Prof. W. Yao and Prof. X.D. Cui’s paper titled ‘Valley polarization in MoS2 monolayers by optical pumping’ was highlighted in Ars Technica.
AoE & CRF Awards in HKU Physics
on Theory, Modeling, and Simulation of Emerging Electronics
Project Coordinator: F.C. Zhang (HKU)
PIs: J. Wang (HKU), G.H. Chen (HKU), L.J. Jiang (HKU), H. Guo (McGill and HKU), W.C. Chew (UIUC and HKU), M.S. Chan (HKUST), P.C.H. Chan (PolyU)
Co-Is: X.D. Cui (HKU), W. Yao (HKU), E. Lam (HKU), D.S.H. Lo, (HKU), P.W.T. Pong (HKU), N. Wong (HKU), K.L. Wu (CUHK), J.N. Wang ( HKUST), Y.J. Yan (HKUST)
This is a multi-institutional interdisciplinary project held by The University of Hong Kong, The Hong Kong University of Science and Technology, and The Chinese University of Hong Kong, and is funded by the Areas of Excellence Scheme. The current project team comprises Professor Fu-Chun Zhang (Physics, HKU), Professor Philip Chan (Provost, PolyU), Professor Guanhua Chen (Chemistry, HKU), Professor Weng-Cho Chew (EE, HKU), Professor Hong Guo (Physics, McGill Univ.), Professor Jian Wang (Physics, HKU), and several co-investigators.
The project strives to develop a suite of multi-scale electronic design automation (EDA) tools ranging from atomistic simulation methods to circuit simulators and to electromagnetic solvers for electrical signals for emerging sub-22nm technology. With these tools, we will study the sub-22nm devices and their systems; and calculate their physical and dynamical properties, and explore the possible paradigm shifts of next generation electronics. Our objectives are specifically listed below:
- To simulate from first-principles the electrical properties and processes of sub-22nm devices with atomistic details
- To investigate lithography modeling, and to employ efficient electromagnetic solvers to simulate electrical signals, power delivery, crosstalk, interference, and noise in multi-scale complex integrated circuits
- To calculate and model the electrical, chemical and mechanical properties of new materials for sub-22nm technology
- To develop modeling tools for emerging spintronics
- To use electron beam lithography technology to fabricate the sub-22nm devices for measurement and calibration of the parameters in our EDA tools
- To develop a set of multi-scale EDA tools for emerging devices and integrated circuits
HKU, PolyU, HKUST
Two-Dimensional Transistion-Metal Dichalocigenides - from Materials, Physics to Devices
Project Coordinator: M. H. Xie (HKU)
Co-Is: W. Yao (HKU), X.D. Cui (HKU), S.Q. Shen (HKU), J.N. Wang (HKUST), N. Wang (HKUST), J.H. Hao (PolyU)
Atomically thin two-dimensional (2D) transition-metal dichalcogenides (TMDCs) are attracting high interests due to their novel properties as well as the ultimate miniaturization in thickness that promises nano-electronics and nano-optoelectronics. They are semiconductors with multi-valley band structures where electrons are labeled both by the spin and valley pseudo-spins, offering ideal platforms to exploring new concept devices utilizing these internal degrees of freedom. Their visible frequency range direct band-gap is ideal for optoelectronic and solar energy applications.
Bulk TMDCs exist in the form of stacks of covalently bonded hexagonal quasi-2D lattices packed by weak van der Waals forces. Flakes of monolayer TMDCs can be prepared by micromechanical cleavage (e.g., using Scotch tape) and by ion- intercalation, for example. Using the “flake” samples, people have discovered interesting properties of these 2D materials. Prototype devices have been made to demonstrate the concepts and viability of using gapped 2D semiconductors for electronic devices. However because the flake samples are small and not very reproducible, explorations of such materials remain hindered by the availability of high quality wafer-scale samples. There is an increasing demand of better and wafer sized samples for characterization and device fabrications.
In this proposal, we bring together a team of active researchers of complementary background and expertise for a concerted effort aiming at (1) producing high quality wafer scale 2D TMDC samples; (2) exploring spin and valley related new physics and properties of 2D TMDCs and examining the effects of defects; (3) experimenting device fabrication and characterization. The collaboration of theoretical and experimental teams in this proposal will ensure a comprehensive and productive research program, leading to new findings that likely impact on the advance towards future nano- electronics and nano-optoelectronics.
HKUST, CUHK, HKU
New Topological States in Cold Atom and Condensed Matter Physics Systems
Project Coordinator: T.K. Ng (HKUST)
Co-Is: K.T. Law (HKUST), S.Q. Shen (HKU), S.Z. Zhang (HKU), Q. Zhou (CUHK)
Topological state of matter is now considered to be the most exciting area of research in hard condensed matter physics because of their rich new physics, and because of their exciting promise for application in quantum information. Remarkably, as activities in topological matter flourishes, an independent dramatic development in cold atoms on the creation of synthetic gauge fields and spin-orbit coupling between atoms have brought these two exciting development together. The reason is that spin-orbit coupling is the basic ingredient for the construction of many topological matters, and the great flexibilities of cold atom experiments raises the hope to realise many topological states hard to achieve in condensed matter systems, as well as to realise many new topological states of fundamental interests unique to cold atoms. Our project combines the existing strength of researchers in the area of topological order at condensed matter systems (TK Ng, KT Law and SQ Shen) and researchers in Cold atoms (S.Z. Zhang and Q. Zhou) to build a strong theoretical research team to explore this new and exciting area of research.
CUHK, HKUST, HKU
Searching for New Physics with the Large Hadron Collider
Project Coordinator: M.C. Chu (CUHK)
Co-Is: H.F. Chau (HKU), L. Flores Castillo (U. of Wisconsin), K.B. Luk (U.C. Berkeley and HKU), G.M.L. Shiu (HKUST), C. Young (Stanford Linear Accelerator Center and CUHK)
Built upon our successful experience in the Daya Bay Reactor Experiment and the supporting Aberdeen Tunnel Experiment, and the strong collaboration both between institutions in Hong Kong and between the Hong Kong team and leading institutes overseas and in China, we propose to form a Hong Kong experimental particle physics group to join the ATLAS Collaboration, one of the two major Large Hadron Collider (LHC) experiments at CERN. Deploying the largest detectors and highest energy particle accelerator in the world, the LHC experiments are well positioned for making breakthrough discoveries in fundamental physics. The LHC runs in 2011-3, even though still at roughly half of the designed energy, already produced a huge volume of data. The discovery of the Higgs particle is indeed a result of these runs. We plan to take up tasks on physics analysis of the data accumulated so far, to search for new physics beyond the Standard Model of Particle Physics, and on software development so that the analysis tools will be ready when the beam energy and luminosity both increase drastically with the new LHC run, in 2014.We plan to carry out analysis of the Higgs particle and search for heavy weak bosons W’ and Z’, supersymmetric partners, and dark matter particles. The upcoming upgrade of the ATLAS detector presents a window of opportunity for Hong Kong researchers to contribute to the hardware development of the ATLAS experiment. In particular, we will work on the hardware development, reconstruction and simulation of the muon system. This Hong Kong experimental particle physics group will be an important component of the newly formed Joint Center for Fundamental Physics, by physicists in CUHK, HKU, and HKUST. The group will also benefit from interacting with the particle theory and astrophysics groups under the Joint Center of Fundamental Physics. With the manpower and resources from CUHK, HKU and HKUST together, we believe we can make meaningful contributions to experimental particle physics, one of the most important endeavors in human being’s quest to understanding Nature.
HKUST, CUHK, HKU
Research in Fundamental physics: from the Large Hadron Collider to the Universe
Project Coordinator: G.M.L. Shiu (HKUST)
Co-Is: H.S.H. Tye (HKUST), T. Liu (HKUST), H.B. Li (CUHK), K.S. Cheng (HKU)
Fundamental physics addresses some key questions of Nature: What are we made of? What are the fundamental forces and matter in Nature? What is the origin of our Universe? These questions are intimately connected. Although key questions in fundamental physics are few, in contrast to other areas of scientific research, they are some of the most challenging ones in science. Advance towards their comprehension and solution requires big teams of experimentalists to extract important data, whose implications lead theorists to explore new possibilities and to make the predictions for experimentalists to test.
With the discovery of the Higgs particle at CERN’s Large Hadron Collider (LHC) in the past year, we now have a rather complete picture of what we are made of: electrons, quarks and gluons, the latter two combine to form protons, neutrons and nuclei, while the masses of fundamental particles (electrons, quarks etc.) come from the Higgs field.
Meanwhile, game-changing discoveries in astrophysics and cosmology have shaped our understanding of Nature at large scales. Observational data reveal that all known matter constitutes less than 5% of the total energy-matter content of the universe, and the remaining 95% is made up of dark matter and dark energy. While the observational evidence for dark energy (Nobel Prize 2011) is compelling, its theoretical underpinning remains a great mystery. Likewise, the existence of dark matter opens the next frontier in particle physics: the search for new physics beyond the Standard Model that we now know. Importantly, physics of the large and the small are deeply intertwined. With precise data, we can probe with high accuracy the early universe where fundamental physics leaves its fingerprints. These measurements provide strong support for cosmic inflation in which the early universe was driven by an enormous dark energy, thus explaining the origin of the hot big bang.
Fundamental physics is a brand new initiative in Hong Kong. This proposal focuses on its theoretical aspects because we have now a critical mass of theoretical physicists in Hong Kong working on these areas while the experimental program is actively being developed. As fundamental physics enters a data-rich era, it is crucial for theorists and experimentalists to collaborate closely. Theoretical studies are key to understanding the vast amount of data and designing new search strategies. Our team comprises researchers with complimentary expertise in a wide range of interconnected areas in particle physics, astrophysics, and cosmology.
HKU, CUHK, HKUST
Quantum Control and Quantum Information Processing
Project Coordinator: Z.D. Wang (HKU)
Co-Is: W. Yao (HKU), H.F. Chau (HKU), R.B. Liu (CUHK), S. Du (HKUST)
Quantum control and quantum information processing using atomic optical systems and solid state systems are cutting edge sciences with applications in device science, communication, cryptography, and metrology. In this collaborative project, we bring together the existing research strength in these areas in Hong Kong to form a team to address important issues in these areas. In particular, we will concentrate on the experimental studies on quantum state control, quantum information processing, and quantum communications using systems including photons, atoms and artificial atoms in solids. These studies will be backed up by the theorists in our team. We expect that the collaborative research in this emerging interdisciplinary field will not only advance our understanding of the exotic quantum world, but also expand our imagination for tomorrow’s quantum technological innovation.
HKU, CUHK, HKUST
Nano-Spintronics - Quantum Control of Electron Spins in Semiconductors
Project Coordinator: F.C. Zhang (HKU)
Co-Is (HKU-Physics): X.D. Cui, S.Q. Shen, M.H. Xie
Spin based electronics or spintronics as a new generation of electronics is an emerging field with a great promise to advance the semiconductor industry. Spintronics aims to use electron’s spin, a tiny magnet or compass, to replace the role of electric charge in electronics. Metallic spintronics has already had a lot of applications. One of the recent focuses is the generation, manipulation and detection of spin-current, a counterpart of charge current, which may open a new route in the future spintronics. In this group project we will consolidate the existing research strength in both experiment and theory to form a versatile team in Hong Kong to focus on the generation and detection of the spin current.
HKUST, HKBU, CUHK, HKU
Quantum Order in Novel Materials: Superconductivity and Topological Order
Project Coordinator: T.K. Ng (HKUST)
Co-Is (HKU-Physics): S.Q. Shen, Z.D. Wang, and F.C. Zhang
Iron-based (pnictides) superconductors and topological insulators are the most important discoveries in hard condensed matter physics in recent years. The two classes of materials exhibit the common feature of exotic quantum behaviors (quantum order). Elucidating the principles that govern the properties of these materials and exploring their technological implication are the goals of the physics community. The complexity in tackling the many intervening issues in this area calls for a collaborative approach. With the help of a previous Collaborative Research Grant, a research team to tackle this problem is ready. The proposal consolidates the team to study holistically the novel quantum order behind these materials and to explore the nature of general topological order, a key ingredient in quantum information science. Several team members have entered this new field with influential results already produced. The goal of the team is to continue the high-quality research and become internationally recognized.
CUHK, HKU, U.C. Berkeley (USA) and IHEP, CAS (China)
High Precision Measurement of Neutrino Oscillation at Daya Bay
Project Coordinator: M.C. Chu (CUHK)
Co-Is (HKU-Physics): K.S. Cheng, J.K.C. Leung and J.C.S. Pun
The recent discovery of neutrino oscillation – a neutrino travelling in space transforms from one type to another – has profound impacts on particle physics, astrophysics and cosmology. The Daya Bay Reactor Neutrino Oscillation Experiment aims to measure a key but yet unknown neutrino oscillation parameter, θ13, to an unprecedented precision of better than 3 degrees, which is critical to the design of future experimental tests of a possible explanation of why matter dominates anti -matter in the universe, a key condition for our existence.
The Hong Kong team has been an active member of the Daya Bay Collaboration, an international team with 38 institutions. We will contribute to the commissioning and monitoring of the experiment and analysis of data, with the help of a subsystem of the antineutrino detector built by our team. We will also design and construct a continuous radon monitoring system as well as a cover gas system to minimize radon contamination of the detectors.
More details please refer to here.
CityU, HKUST, HKU
Studies of Fundamental Properties of Nanosurfaces and Selected Applications
Project Coordinator: M.A. Van Hove (CityU)
Co-Is (HKU-Physics): A. Djurisic and H.S. Wu
The performance of nanoscale devices is often dominated by their surface properties. For example, surfaces introduce undesired electronic states in electronic and optoelectronic devices constructed from semiconducting nanostructures. By contrast, surface activity should be enhanced in nanostructures used as antibacterial agents. To improve such performance, our aim is to provide quantitative atomic-scale information about nanoscale surfaces. Our project will achieve this by introducing a new methodology: we will intentionally design and fabricate novel and highly-controlled nanoplatforms that allow for the first time detailed determination of surface structure and modeling of their relevant surface properties.