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
Title:
Late Stage Stellar Evolution
Research
at HKU and the Laboratory for
Space Research
Abstract
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.
Brief Bio
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.
March 06, 2018
Jiunn-Wei
Chen , NTU-physics
Host:
Xiao-Gang
He
Time: 2:20 pm -3:20 pm
Place: Room 204, CCMS-New Phys. building
Title:
Fun
with QCD
Abstract
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.
Brief Bio
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.
Slides
March 13, 2018
Chung-Yu
Mou, NTHU-physics
Host:
Xiao-Gang
He
Time: 2:20 pm -3:20 pm
Place: Room 104, CCMS-New Phys. building
Title:
Searching for Exotic
Superconductivity
in Topological Materials
Abstract
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.
Brief Bio
EDUCATION:
1993 Ph. D., Physics, Caltech
1986 B.S., Physics, NTU
PROFESSIONAL EXPERIENCE:
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
March 20, 2018
Chong-Sun
Chu
,
NTHU-physics
Host:
Xiao-Gang
He
Time: 2:20 pm -3:20 pm
Place: Room 104, CCMS-New Phys. building
Title:
Holography, Quantum
Information and
String Theory
Abstract
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.
Brief Bio
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.
Slides
March 27, 2018
Sergey
Savrasov ,
UC,
Davis
Host:
Guang-Yu
Guo
Time: 2:20 pm -3:20 pm
Place: Room 104, CCMS-New Phys. building
Title:
Topological Quantum
Materials
Abstract
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.
Brief Bio
Professional Preparation
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.
Appointments
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:
http://scholar.google.com/citations?user=74J2KskAAAAJ&hl=en
Synergistic Activities
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
April 10, 2018
Yee
Bob Hsiung,
NTU-physics
Host:
Xiao-Gang
He
Time: 2:20 pm -3:20 pm
Place: Room 104, CCMS-New Phys. building
Title:
Neutrino Oscillation and
Mass
Hierarchy from Daya Bay and JUNO
Abstract
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.
Brief Bio
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.
April 17, 2018
Seng
Ghee Tan
,
NTU-physics
Host:
Xiao-Gang
He
Time: 2:20 pm -3:20 pm
Place: Room 104, CCMS-New Phys. building
Title:
Quantum Physics of
Modern
Nanoscale Electronics
Abstract
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.
Brief Bio
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).
May 08,
2018
Hyung-Bin
Son,
Chung-Ang
University
Host:
Ya-Ping
Hsieh
Time: 2:20 pm -3:20 pm
Place: Room 104, CCMS-New Phys. building
Title:
Analysis of Gas Evolution
in
Commercial Supercapacitors
and Lithium Ion Batteries Using
Raman Spectroscopy
Abstract
Rechargeable energy storage devices, such as Li-ion batteries and
supercapacitors, are at the heart of widely used electrical devices
such as smartphones and electric vehicles. As the energy density of
these devices steadily increases, safety concerns are growing. Toxic
and/or explosive gases may evolve as a result of decomposition of the
electrolyte and/or the electrode material and these gases are generally
trapped in the cell. However, the characterization of assembled cells
has been limited to measuring externally accessible parameters such as
voltage, current and temperature. Thus, there was little information
about the composition of the evolved gases and the mechanism of gas
evolution.
This talk introduces a new way to measure the evolved gases from
commercially available cells using Raman spectroscopy. This is made
possible by designing external Raman cells for supercapacitors and
Li-ion battery cells. Using those cells, we were able to identify
evolved gas species and to track the partial pressures of individual
gases in real time. We will also talk about the effects of harsh
conditions such as high voltage and temperature on the gas evolution
and electrochemical performance of the cells.
Brief Bio
Prof. Son is an applied scientist and electrical engineer. His earlier
work focused on Raman spectroscopy of carbon nanotubes and graphene.
His main interest now is to expand Raman spectroscopy to more practical
applications such as battery safety and stem cell research.
Education
2003, BS, Electrical Engineering and Computer Science, MIT
2004, BS, Physics, MIT
2004, MEng, Electrical Engineering and Computer Science, MIT
2008, Ph.D, Electrical Engineering and Computer Science, MIT
Professional Experience
2008-2011, Research staff member, Samsung Advanced Institute of
Technology
2012~2015, Assistant Professor, School of Integrative Engineering,
Chung-Ang University, Republic of Korea
2016~2017, Associate Professor, School of Integrative Engineering,
Chung-Ang University, Republic of Korea
May 15, 2018
Roger
A. Chevalier
,
University
of Virginia
Host:
Naomi
Hirano
Time: 2:20 pm -3:20 pm
Place: Room 104, CCMS-New Phys. building
Title:
Superluminous Supernovae
Abstract
Unbiased supernova searches led to the recognition of the class of
superluminous supernovae (SLSN) about one decade ago. These events can
be a factor 100 more luminous than ordinary supernovae. Some SLSNe show
narrow hydrogen lines and are likely powered by interaction with a
dense circumstellar medium. In one case, the progenitor star lost
several solar masses of gas in the 30 years leading to the explosion;
the reason for the extreme mass loss is not understood.
Other
SLSNe do not show narrow lines, but show broad lines and are stripped
of hydrogen. These features are difficult to explain in an interaction
scenario. Another possibility is radioactive power, but the required
mass of 56Ni can be larger than allowed by the light curve and the
expectations of 56Ni synthesis. Power from a magnetar (highly
magnetized pulsar) with a millisecond period can roughly explain light
curves
and spectra.
Brief Bio
Roger Chevalier
has been the W. H. Vanderbilt Professor of Astronomy at the University
of Virginia since 1990. After obtaining his Ph.D from Princeton
University in 1973, he joined the scientific staff of Kitt Peak
National Observatory in Tucson, Arizona. He moved to the University of
Virginia in 1979, where he was Astronomy Department chair during
1985-1988 and 1989-1992. His research has centered on theoretical
studies of rapidly expanding astronomical sources, including
supernovae, supernova remnants, gamma-ray bursts, pulsar wind nebulae,
and galactic super-winds. Chevalier was chair of the science panel on
Stars and Stellar Evolution for the 2010 astronomy decadal survey. His
honors include Virginia's Outstanding Scientist Award (1991), the
Dannie Heineman Prize for Astrophysics (1996), and election to the
National Academy of Sciences (1996).
May 22,
2018
Hai-Yang
Cheng,
IoPAS
Host:
Xiao-Gang
He
Time: 2:20 pm -3:20 pm
Place: Room 104, CCMS-New Phys. building
Title:
Are there multi-quark
hadrons?
Abstract
The quark model has been applied very successfully in describing the
mesons and baryons and their properties. It is known that all the
established mesons are made of a quark and an antiquark, while baryons
are composed of three quarks. In principle, hadrons composed with more
than three valence quarks are not prohibited by the fundamental theory
of strong interactions, namely the so-called QCD. In this talk I'll
examine the status of the multi-quark hadrons, including tetraquark
mesons, pentaquark baryons and hexaquark states. I will also explain
why the quark model often encounters a great challenge in understanding
p-wave scalar mesons and p-wave baryons.
Brief Bio
Education
December, 1980 Ph.D. in Physics Purdue University, USA
July, 1973 M.S. in Physics National Tsing Hua University, Taiwan
July, 1971 B.S. in Physics National Cheng Kung University, Taiwan
Academic Positions
2012-
Distinguished Research Fellow, Institute of Physics Academia Sinica
1988-2012
Full Research Fellow, Institute of Physics Academia Sinica
2010
Visiting Professor, SUNY at Stony Brook
2009-2010
Visiting Professor, Brookhaven National Lab
2001-2002
Visiting Professor, SUNY at Stony Brook
2000-2001
Visiting Professor, Brookhaven National Lab
1992-1993
Visiting Professor, SUNY at Stony Brook
1987-1988
Visiting Expert, Academia Sinica
1986-1987
Visiting Scientist, Indiana University
1985-1986
Chester Davis Fellow, Indiana University
1983-1985
Research Associate, Brandeis University
1982-1983
Visiting Assistant Professor, Purdue University
1980-1982
Research Associate, Purdue University
Professional Experience
6/1984-7/1984, 9/1988-10/1988, 8/1989-1/1990, 8/1991-10/1991,
9/2000-9/2001, 6/2009-5/2010
Research Collaborator, Brookhaven National Laboratory
1990
Organizer of the CP parallel session of the XXVth International
Conference on High Energy Physics
1990-2003
Editor, Chinese Journal of Physics
1994-1996
Editor-in-Chief, Chinese Journal of Physics
1994-1996
Physics Panel Committee of Natural Science Division, National Science
Council 國科會自然處物理學門審議委員
1994-1995
Project Coordinator, National Science Council 國科會自然處物理學門審議人
1996-1999
Consultation Committee, National Science Council 國科會自然處諮議委員
1998-2000
Chairman of the Taiwan High Energy Experiment Planning Committee
1999-2000
Deputy Director, Institute of Physics, Academia Sinica
Honors Received
1980
G. W. Tautfest Memorial Award, Purdue University
1985
Chester Davis Fellowship, Indiana University
1988-1990, 1990-1992, 1992-1994, 1994-1996
Outstanding Research Award of National Science Council 國科會傑出獎
1994
Fellow of Chinese Physical Society 中華民國物理學會會士
1994
Academic Award, Ministry of Education 教育部學術獎
1996-1999, 1999-2002
Special Research Fellow, National Science Council 國科會特約研究員
2004
Citation Award of Chinese Journal of Physics
2010
Outstanding Referee, American Physical Society
May 29,
2018
Chia-Ling
Chien, Johns Hopkins
University
Host:
Ssu-Yen
Huang
Time: 2:20 pm -3:20 pm
Place: Room 104, CCMS-New Phys. building
Title:
From Stern-Gerlach Experiment
to
Spin Orbit Torque, the Unending Saga of Spin
Abstract
Since the fortuitous discovery by Otto Stern and Walther Gerlach in
1922, electron spin has dominated many branches of condensed matter
physics, especially spintronics and superconductivity. In addition to
the interesting historical accounts, we will describe some of the
recent development of pure spin current phenomena and spin orbit
torque.
Brief Bio
Chia-Ling Chien is the Jacob L. Hain Professor of Physics at The Johns
Hopkins University. He received his BS in physics from Tunghai
University (Taiwan), and his MS and PhD from Carnegie-Mellon
University.
His current research interests include spintronics, pure spin current
phenomena, and superconductors. He is a Fellow of the American Physical
Society and a Fellow of the American Association for the Advancement of
Science (AAAS). He is the recipient of the David Adler Award of the
American Physical Society (2004) and the IUPAP Magnetism Award and Néel
Medal (2015).
June 05, 2018
Chia-Chen
Hsu, CCU-Physics
Host:
Ya-Ping
Hsieh
Time: 2:20 pm -3:20 pm
Place: Room 104, CCMS-New Phys. building
Title:
Enhancing
Upconversion
Luminescence of Rare Earth
Nanoparticles in Aqueous Solution
with Low Refractive Index
Resonant Waveguide Grating
Abstract
The enhancement of up-conversion luminescence (UCL) of rare earth doped
up-conversion nanoparticles (UCNPs) in aqueous solution is particularly
important and urgently required for a broad range of biomedical
applications. Herein, an effective approach to achieve highly enhanced
UCL from NaYF4:Yb3+, Tm3+ UCNPs in aqueous solution is presented.
We demonstrate that UCL of these UCNPs can be enhanced more than 104
fold by using a mesoporous silica low refractive index resonant
waveguide grating (low-n RWG) in contact with aqueous solution, which
makes it well-suited for biomedical applications. The structure
parameters of the low-n RWG are tuned via rigorous coupled-wave
analysis simulation to ensure strong local excitation field to form
atop the TiO2 surface of the low-n RWG, where UCNPs are deposited. As
the low-n RWG is excited by a near near-infrared laser to match its
guided mode resonance (GMR) condition, UCL emitted from UCNPs is
greatly enhanced thanks to the strong interaction between excitation
local field and UCNPs. UCL emission of UCNPs can be further enhanced
about two to four times when the UCL emission condition (wavelength and
angle) matches with the GMR condition.
Furthermore, we show that the presence of biotin molecules atop of the
low-n RWG can be easily detected through UCL emission generated from
streptavidin-functionalized UCNPs with the help of the
streptavidin-biotin specific binding. The results indicate that the
low-n RWG has high potential for UCL bio-sensing and bio-imaging
applications.
References:
1. “Giant enhancement of upconversion fluorescence NaYF4:Yb3+,Tm3+
nanocrystals with resonant waveguide grating substrate”, ACS Photonics,
2, 530 (2015).
2. “Enhancing upconversion luminescence emission of rare earth
nanophosphors in aqueous solution with thousands fold enhancement
factor by low refractive index resonant waveguide grating”, ACS
Photonics, DOI: 10.1021/acsphotonics.8b00494, (2018).
Brief Bio
Education
Ph.D. Degree: Department of Physics, University of Arizona, USA,
1984/08-1991/09
Master Degree: Institute of Optical Sciences, National Central
University, Taiwan, 1982/09-1984/06
B.S. Degree: Department of Physics, National Central University,
Taiwan, 1977/09-1981/06
Work Experience
2016/01-present
Distinguished Professor, Department of Physics, National Chung Cheng
University, Taiwan
2015/09-2015/01
Invited Professor, Laboratoire de photonique quantique et moléculaire,
École normale supérieure de Cachan, France
2009/08–2012/07
Dean of College of Science, National Chung Cheng University, Taiwan
2006/05-2006/08
Visiting Professor, Department of Physics, University of British
Columbia, Canada
2002/07–2005/07
Director, Graduate Institute of Opto-Mechatronics, National Chung Cheng
University, Taiwan
2001/08–present
Professor, Department of Physics, National Chung Cheng University,
Taiwan
1991/08-2001/07
Associate Professor, Department of Physics, National Chung Cheng
University, Taiwan
Awards
2009 Outstanding research award, National Chung Cheng University
2016 Distinguished Professor, National Chung Cheng University
Research Interests
Nanophotonics, Nonlinear Optics, Organic Electronics, Polymer Optics
June 12,
2018
Benjamin
Fong Chao,
IEAS
Host:
Xiao-Gang
He
Time: 2:20 pm -3:20 pm
Place: Room 104, CCMS-New Phys. building
Title:
Earth's Rotation
Abstract
Rotation is a wonderful thing in physics, and the Earth's rotation
varies with time. How does it vary? Why? How do we know? What has NASA
to do with it? What does it reveal about the Earth's mysteries? Come
and hear the story.
Brief Bio
Education
1973
B.S. Physics, National Taiwan University.
1981
Ph.D. Earth Sciences, Scripps Institution of Oceanography, University
of California, San Diego.
Honors and Awards
1990
Excellence in Refereeing: J. Geophys. Res., Amer. Geophys. Union.
1991, 1992, 1994, 1995, 1996, 1998, 2000, 2003, 2004 (9 times)
NASA GSFC Outstanding Performance Awards.
1995
Fellow, International Association of Geodesy.
2005
Honorary Professorship, University of the Chinese Academy of Sciences,
Beijing.
2005
The Einstein Professorship, Chinese Academy of Sciences.
2006~
Adjunct Researcher, Institute of Geodesy and Geophysics, Chinese
Academy of Sciences, Wuhan.
2006 ~ 2008
TSMC Outstanding Chair Professorship.
2009 ~ 2010
Foundation for the Advancement of Outstanding Scholarship Award.
2010 ~
Distinguished Research Fellow, Academia Sinica.
Major Fields of Interest
1. Global geophysics and planetary physics by way of (space)
geodesy–Rotation dynamics; Gravitational variations; Free oscillations;
Global sea level; Geophysical fluids changes.
2. Digital data analysis methodology and numerical techniques; Inverse
theory.
趙丰博士為台灣大學物理系畢業、美國加州大學聖地牙哥校區 Scripps Institution of Oceanography
地球科學博士(1981)。在美國 NASA Goddard Space Flight Center
服務多年﹐任太空測地實驗室主任。2006年回到台灣，曾任中央大學地球科學院院長，和中央研究院地球科學研究所所長，現任該所特聘研究員。研究專長為地
球與行星動力學、重力學、地球物理與地震學等。
June 19, 2018,
2018
Atsushi
Taruya,
Kyoto University
Host:
Naomi
Hirano
Time: 2:20 pm -3:20 pm
Place: Room 104, CCMS-New Phys. building
Title:
Relativistic Effects on
Observed
Large-Scale Structure of the Universe
Abstract
The large-scale structure of the Universe observed via galaxy redshift
surveys contains valuable cosmological information, and it has been
playing a major role to improve our understanding of the Universe.
However, the observed large-scale structure appears distorted due to
the observed systematics in the redshift determination, known as
redshift-space distortions (RSD). Recently, the measurement of RSD is
renewed with great interest as a probe of gravity on cosmological
scales. In this talk, after reviewing the 'standard' RSD caused by the
peculiar velocity of galaxies, I will discuss yet another distortion
arising from general relativistic effects. Unique
feature of the new distortion effects is demonstrated based on the
simulated catalog taking a proper account of the relativistic effects,
and detectability and implications to cosmology will be also discussed.
Brief Bio
Education:
1993 B.A., School of Science, Department of Physics, Nagoya University
1995 M.S., Graduate school of Science, Division of particle and
astrophysical sciences, Nagoya University
1998 Ph.D., Graduate school of Science, Division of particle and
astrophysical sciences, Nagoya University
Fellowships and positions:
1998 – 1999 Research fellow, Faculty of Integrated Human Studies, Kyoto
University
1999 – 2000 Research fellow, Research Center for the Early Universe,
School of Science, The University of Tokyo
2000 – 2001 Research Fellow of Japan Society of Promotion of Science,
Department of Physics, The University of Tokyo
2001 –2013 Assistant Professor, Research Center for the Early Universe,
School of Science, The University of Tokyo
2013 – Associate Professor, Yukawa Institute for Theoretical Physics,
Kyoto University
Awards
The 2016 Yukawa-Kimura prize, “exploration of precision nonlinear
perturbation theory for gravitational evolution of structures in the
universe”, Yukawa memorial foundation (18th Jan. 2017)
Research Themes:
Prof. Taruya’s main research activities are the studies of the
large-scale structure of the universe in the subject of observational
cosmology. He has worked more particularly on the statistics and
dynamics of large-scale structure both from the theoretical and
observational point-of-view. Further, he has been working on several
interdisciplinary topics relating to cosmology. Topics include
statistical mechanics of self-gravitating system, gravitational-wave
backgrounds, and measurements/characterization of exoplanets.