February 27, 2018
Quentin Parker , HKU-physics
Host: Yuan-Huei Chang
Time: 2:20 pm -3:20 pm
Place: Room 104, CCMS-New Phys. building
Late Stage Stellar Evolution Research
at HKU and the Laboratory for
The research of the world-leading group in late stage stellar evolution will be described with a particular focus on planetary nebulae and the Hong-Kong AAO strasbourg H-alpha PN research platform: HASH. A brief description of the aims and mission on the new Laboratory for Space Research will also be presented.
Prof. Quentin Parker is currently Associate Dean (Global) of the Faculty of Science at HKU and acting director of the Laboratory for Space Research.
Quentin obtained a BSc(Hons) in 1982 and a PhD (1986) from the University of St. Andrews. He joined the department of Physics at Hong Kong University in March 2014. Prior to that he was the joint AAO/Macquarie lecturer in astronomy (2002-2015) and director of the research centre for Astronomy, Astrophysics and Astrophotonics (2010-2014). Quentin also worked at the Royal Observatory Edinburgh (1986-1992), Anglo-Australian observatory (1992-1999) and as a senior research fellow at the Institute for Astronomy in Edinburgh (1999-2002). Quentin was responsible for helping to develop the FLAIR-II and 6DF fibre-spectroscopy systems at the UKST and supported the 2dF and AAOmega multi-object fibre spectroscopy systems on the AAT.
Quentin was also P.I. for the UKST H-alpha survey of the Southern Galactic Plane. Research activities are mainly but not exclusively associated with Wide Field Astronomy, including large-scale redshift surveys, low-surface brightness galaxies, supernova remnants and especially Planetary Nebulae. He has supervised and co-supervised a significant number of PhD, MSc and honours students to successful completion and is always keen to attract students. Quentin is currently on the IAU working group on planetary nebulae. He also heads both the H-alpha international survey consortium and the associated 'MASH' Planetary nebulae team. He also has a life-long interest in antiquities and a strong interest in Chinese Bronze artefacts.
Nuclear physicists share the same appreciation with condensed matter physicists that complex phenomena can emerge when the system has a large amount of particles. The challenge is how to link the complexity to the fundamental theory of strong interaction – Quantum Chromodynamics (QCD). I will present one rare example showing how this could be done.
Jiunn-Wei Chen is professor of Physics at National Taiwan University (NTU). Prof. Chen received his undergraduate degree from Tsinghua University, a MS degree from NTU and Ph. D. from the University of Washington, Seattle. He was a postdoc at Maryland and then MIT before joining the faculty of NTU. He was the director of the NCTS north branch and NTU-CTS. He was also the associate director and now a center scientist of LeCosPA.
Prof. Chen is a nuclear theorist. He is perhaps most well known for his work on nuclear effective theory and its great simplification on weak interaction processes in nuclear physics, which was used by the SNO collaboration in their Nobel prize winning experiment to solve the solar neutrino problem. In addition, Prof. Chen also has highly cited work on the cosmological constant problem, lattice QCD and quantum phases. Prof. Chen has more than one hundred papers so far. His work was recognized by a Dissertation in Nuclear Physics Award from the American Physical Society, Ta-Yu Wu research award from NSC, and two Gold-Jade Research Awards from NTU.
In this talk, I will first give an overview of recent progress on the research of superconductivity. Possible forms that superconductivity can occur will then be discussed. In particular, in light of recent discovered topological materials, I will show that it is possible to create exotic forms of superconductivity in these materials by resorting to their topological nature. As examples, I will discuss three different forms of superconductivity that can be realized in topological materials, including strained induced pair density waves (superconductivity due to Cooper pairs with non-zero center of mass momentum), topological superconductivity through engineering thickness of sample, and spontaneously generated Majorana fermions by geometry.
1993 Ph. D., Physics, Caltech
1986 B.S., Physics, NTU
8/2013-7/2017 Chairman, Physics department, NTHU
8/2007-12/2009 Division Head, Physics division, NCTS
2006-2007, 8/2010-7/2013 Director of Physics Promotion Center
8/2002-present Professor, Physics department, NTHU
AWARDS AND FELLOWSHIP:
2011 Fellow of the physics society of ROC
2008 MOST outstanding research awards
Holographic Principle asserts an equivalence between quantum systems with objects in gravitational fields in a higher dimensional spacetime. The suggestion of holography originated from the work of Hawking, Bekenstein and others on the quantum properties of blackholes, and it has been proposed as a fundamental principle of quantum gravity and spacetime by ‘t Hooft and Susskind. One of the remarkable progresses of string theory in the last twenty years is the realization of this principle in terms of the AdS/CFT correspondence. In this colloquium, I will talk about how developments in string theory has contributed to the understanding of this principle.
Recently an intriguing connection between quantum entanglement between micro-scopic degrees of freedom in a quantum theory and geometric properties of spacetime in the gravitational theory has been pointed out. This surprising perspective has leaded to new insights in the understanding of quantum information, and its relation with holography and the nature of spacetime. I will highlight some of these recent progress as well.
Dr. Chong-Sun Chu is a Professor of Physics, NTHU and Tsing-Hua University Chair Professor and Director of the Physics Division of the NCTS.
Dr. Chu was born in Hong Kong. He received his BSc in Physics from the Chinese university of Hong Kong, and his PhD degree from UC Berkeley. He has held research appointments at the International Advanced Studies Institute, SISSA in Trieste, Italy and the Institute of Theoretical Physics in Neuchatel, Switzerland before joining the Durham university, UK as a faculty. There he held a Chair position in the department of Mathematics until 2014.
Dr. Chu research interests is in fundamental problems in high energy physics and cosmology. He has made contributions in a vast number of topics in string theory, such as the origin of noncommutative geometry of spacetime, noncommutative cosmology, AdS/CFT correspondence, branes in M-theory etc. Recently he has interest focused on the intriguing relation between quantum information and holography.
Dr. Chu has held visiting positions in CERN (Switzerland), Max Planck Postdam (Germany), Issac Newton Institute, Cambridge (UK), Perimeter Institute (Canada), International Center of Theoretical Studies, ITP (China) and KEK (Japan). He has received the Outstanding Scholar Chair award from Taiwan and the EPSRC Advanced Fellow from UK. He is a Fellow of the Institute of Physics and a Fellow of the Higher Education Academy.
Topological quantum solids are a new class of systems that behave as an insulator or semimetal in the bulk but whose surface contains conducting states meaning that the electrons can primarily move along the surface of the material. Starting a decade ago from the original proposal on the principal existence of such state of matter in the case of two dimensions called a quantum spin Hall insulator and its subsequent extension to its three-dimensional analog called a topological insulator, the field has been recently enriched by the discoveries of new topological phases such as topological crystalline insulators, Weyl semimetals, Dirac semimetals, and nodal line semimetals. Their unusual properties such as robust surface currents insensitive to the disorder or various forms of quantum Hall effects have led to a plethora of proposals for the use of topological materials in fundamental research spanning from magnetic monopoles to Majorana fermions, and in applications such as spintronic devices or fault-tolerant quantum computations.
In this talk I will overview some of the most exotic properties in these systems such as topologically protected surface states in a form of massless Dirac fermions in topological insulators and Fermi arcs in Weyl semimetals. Charge and spin currents in these systems will be studied where we will show that an external electric field creates a flow of spins through the bulk of a topological insulator to their top and bottom surfaces. We will introduce a counterintuitive idea of increase in nonmagnetic impurity concentration in order to preserve such surface spin accumulation. Next, studies of a Weyl semimetal model will be discussed and contrasted to the case of topological insulator. In particular, we find that robustness to surface disorder can be reached for a straight Fermi arc geometry. This produces conductivities at the surface of Weyl semimetals that are one to two orders of magnitude larger of a comparable set up with surface states of topological insulators.
1986, MS, Moscow Engineering Physics Institute, Moscow, Russia
1994. PhD, Lebedev Physical Institute, Moscow, Russia.
1995-1999. Postdoctoral research, Max-Planck Institute, Stuttgart, Germany.
1999-2001. Postdoctoral research, Rutgers University, Piscataway, New Jersey.
Since 2008. Professor, Department of Physics, University of California, Davis, CA.
2005-2008. Associate professor, Department of Physics, University of California, Davis, CA.
2001-2005. Assistant professor, Department of Physics, New Jersey Institute of Technology, Newark, New Jersey.
Five recent publications most closely related to the project
1. Sergey Y. Savrasov, Giacomo Resta, Xiangang Wan, Local Self-Energies for V and Pd Emergent from a Non-Local LDA+FLEX Implementation, arXiv:1802.02471.
2. Yongping Du and Er-Jun Kan, Hu Xu, Sergey Y. Savrasov, Xiangang Wan, Turning Copper Metal into Weyl Semimetal, arXiv:1801.06248.
3. Giacomo Resta, Shu-Ting Pi, Xiangang Wan, Sergey Y. Savrasov, High Surface Conductivity of Fermi Arc Electrons in Weyl semimetals, Phys. Rev. B 97, 085142 (2018).
4. Yongping Du, Xiangyan Bo, Di Wang, Er-jun Kan, Chun-Gang Duan, Sergey Y. Savrasov, Xiangang Wan, Emergence of Topological Nodal Lines and Type II Weyl Nodes in Strong Spin--Orbit Coupling System InNbX2(X=S,Se), Phys. Rev. B 96, 235152 (2017).
5. Yongping Du, Feng Tang, Di Wang, Li Sheng, Er-jun Kan, Chun-Gang Duan, Sergey Y. Savrasov and Xiangang Wan, CaTe: a new topological node-line and Dirac semimetal, NPJ Quantum Materials 2, Article 3 (2017).
Other five recent publications
1. Xingyue Peng, Yiming Yang, Rajiv R. P. Singh, Sergey Y. Savrasov, Dong Yu, Spin Generation Via Bulk Spin Current in Three Dimensional Topological Insulators, Nature Communications 7, 10878 (2016).
2. Shu-Ting Pi, Sergey Y. Savrasov, Manipulating Z2 and Chern topological phases in a single material using periodically driving fields, Scientific Reports 6:22993 (2016).
3. X. Wan, S. Y. Savrasov, Turning a band insulator into an exotic superconductor Nature Communications 5:4144 (2014).
4. X. Wan, A. Vishwanath, S. Y. Savrasov, Computational Design of Axion Insulators Based on 5d Spinels Compounds, Phys. Rev Lett. 108, 146601 (2012).
5. X. Wan, A. Turner, A. Vishwanath, S. Y. Savrasov, Topological semimetal and Fermi-arc surface states in the electronic structure of pyrochlore iridates, Phys. Rev. B 83, 205101 (2011).
Google Scholar Profile Link:
Since 2016: Associate Editor, NPJ Quantum Materials (NPJ==Nature Partner Journals)
2013-2016: Elected Chair Line of APS Far West Section (CA, NV, HW)
2010-2018: Co-Editor, European Physics Letters
The neutrino oscillation and their mass hierarchy (mass ordering) has been very interesting topics in particle physics. The experimental pursuit and discoveries have been quite fruitful in recent years for such elusive tiny neutral leptons.
In this talk I will introduce the underground Daya Bay reactor antineutrino experiment which discovered the non-zero 3rd mixing angle in April 2012 and their recent results after six years running. I will also give the status of the new initiative JUNO experiment to measure the mass ordering of neutrinos in the near future.
Prof. Yee Bob Hsiung received his bachelor degree (1976) at NTU Physics Department and Ph.D. (1986) in Physics at Columbia University.
He has been working on particle physics experiments of discovering direct CP violation in neutral kaon decays and rare K and B-meson decays, as well as LHC-CMS experiment to search for new physics (top and Higgs), and in recent years on Daya Bay neutrino oscillation experiment discovering none-zero 3rd mixing angle.
He was the co-spokesperson of KTeV experiment at Fermilab before he returned to NTU in 2002 and APS Fellow in 2000.
He received the Outstanding Scholar Awards from the Foundation for the Advancement of Outstanding Scholarship (2003-2008), and was the Physics Department chair and the President of PSROC in Taiwan.
Recently he received the 17th National Professorship of ROC in Taiwan from Ministry of Education. Also sharing the 2016 Breakthrough Prize in Fundamental Physics on Daya Bay experiment.
Modern nanoscale electronics encompasses many new and emerging sub-topics e.g. spintronics (magnetic memory, sensors, spin transistor), relativistic electronics (graphene, Weyl semimetals), topological electronics (topological insulators, Dirac-Weyl, quantum Hall), atomic electronics (nitrogen-vacancy-centers), molecular electronics (carbon nanotubes) and so forth.
In this talk, we will introduce recent advances in these topics as well as the underlying physics that support the fast development of research in these areas. The core concepts of non-equilibrium, size effects, perturbation, as well as gauge and Berry curvature are introduced. We also discuss the electronic environment in which all carrier transport takes place. The effect of ionic potential results in the band structure of metal, semiconductor and insulator. The effect of carrier interaction gives rise to electron gas, liquid and solid.
Seng Ghee Tan received his PhD (2006) and M.Eng (2001) from the National University of Singapore (NUS), and his B.Eng (1996) from the University of Malaya. He was a senior research fellow under the A-STAR of Singapore from 2006-2009. He later held the position of Assistant Professor with the NUS from 2009-2015 before leaving the NUS in 2015 to continue his career with A-STAR as a theoretical physicist until 2017. He was at the same time an editorial board member for the Scientific Reports (NPG). He is presently (2007 onwards) a Visiting Prof at the National Taiwan University (NTU).
In 2007, he predicted a physical effect known as the spin-orbit spin torque, and derived a modified-LLG equation [S.G. Tan et. al. arXiv: 0705.3502 (2007)] to support his prediction. The effect was confirmed by experiment in 2010, and is now used in the study of magnetic memory. In 2015, he predicted theoretically a conductivity correction to the 2D-spin Hall systems. In 2012, he wrote a book: “Introduction to the Physics of Nanoelectronics” (Woodheads Publishing, Elsevier). He has published over 160 journal papers in the emerging fields of spintronics, graphene, Dirac-Weyl, topological physics in materials and electronics. During his professorship with the NUS, he had supervised about 10 PhD students. He had taught many courses in quantum electronics (emerging), quantum transport in nanoscale devices (new materials), quantum spintronics, at both NUS (Singapore) and NTU (Taiwan).
Prof. Maw-Kuen Wu (吳茂昆) is a physicist specializing in superconductivity, low-temperature physics, and high-pressure physics. He was a professor of physics at Columbia University. He made the historic discovery of superconductivity above 77 K in YBCO in 1987. Wu was then invited to teach at the National Tsing Hua University, and conduct further research in high-temperature superconductivity. He served as Chairman of the National Science Council from 2004 to 2006 and the President of the National Dong Hwa University from 2012 to 2016. He currently serves as the Distinguished research fellow of the Institute of Physics at the Academia Sinica and the Minister of Education.
1988 U.S.A. National Academy of Science Comstock Prize
1988 NASA Special Awards
1988 University of Alabama Research Award
1988 State of Alabama Resolution
1988 USA Chinese Association of Engineering Annual Award
1989 Tamkang Golden Eagle Award
1994 Bernd T. Matthias Prize
1994 Fellow, Chinese Physical Society
1995 Y. T. Lee Outstanding Scientist Award
1998 Academician, Academia Sinica
1998 Member, Asia-Pacific Academy of Material
2004 Foreign Associate, US National Academy of Sciences
2004 Member, The Third World Academy of Sciences
2008 Ettore Majorana-Erice-Science for Peace Prize
2010 Humboldt Research Award
2011 Nikkei Asia Prize
2011 Presidential Science Prize
Time: 2:20 pm -3:20 pm
Place: Room 104, CCMS-New Phys. building