Spring 2021 Schedule
Feb 23, 2021
Gunther Roland, Department of Physics, Massachusetts Institute of Technology
Host:
Yang-Fang Chen
Time: 2:20 pm
-3:20 pm
Place: Room 104,
CCMS-New Phys. building
Title:
The strong interaction, emergent phenomena and heavy-ion collisions
Abstract
Among the four fundamental actions in nature, the strong interaction is arguably the most mysterious. Foremost, the strongly interacting particles seen in nature, hadrons like protons and neutrons, are not themselves the basic degrees of freedom of the underlying theory, Quantum Chromo Dynamics (QCD). Rather, the hadrons emerge as complex structures from interactions of the basic building blocks of QCD, quarks and gluons. Calculations suggested that at high temperature and density hadrons should melt into a new state of matter, the Quark-Gluon Plasma. Surprisingly, this state also exhibits novel collective phenomena, which can be studied in nuclear collisions at high energy. I will discuss current results and point out how future experiments can help us understand emergent QCD phenomena in different energy regimes.
Brief Bio
Prof. Roland obtained his PhD at the University of Frankfurt in 1994. After postdoctoral work at MIT and appointments at Frankfurt and CERN, he joined the MIT faculty in 2000, where he is now a Professor of Physics. Most of Prof. Roland's work focused on experimental studies of the strong interaction under extreme conditions, using nuclear collisions at the highest energies. He has served as physics coordinator of the PHOBOS experiment at RHIC and co-convener of the heavy-ion physics group in the CMS experiment at the CERN LHC. He led the CMS discovery of long-range correlations in proton-proton collisions, one of the most surprising results from the LHC to-date. Since 2016, he is co-spokesperson of the sPHENIX experiment under construction at RHIC. Prof. Roland is a former DOE Outstanding Junior Investigator and a Fellow of the American Physics Society.
Video
Video Link
Mar 2, 2021
Daniel Baumann, University of Amsterdam & National Taiwan University
Host:
Yang-Fang Chen
Time: 2:20 pm
-3:20 pm
Place: Room 204,
CCMS-New Phys. building
Title:
The Past, Present and Future of COSMOLOGY
Abstract
Our universe is both simple and strange. It is simple because just 5 parameters, such as the density of dark matter and dark energy, as well as the amplitude of matter fluctuations, describe all cosmological observations. It is strange because we arguably don’t understand any of these parameters. In this talk, I will first describe the astounding progress in observational cosmology that has led to the simple 5-parameter model for our universe. I will then explain why most elements of the standard model of cosmology are still mysterious. In particular, I will describe why the model challenges our understanding of fundamental physics on the both the largest and the smallest scales. Finally, I will look into the future and discuss how upcoming observations can help us to understand our simple, but strange universe.
Brief Bio
Prof. Baumann is a world-leading theoretical cosmologist. He obtained his doctorate from Princeton University in 2008, after which he worked as a postdoctoral researcher at Harvard University and at the Institute for Advanced Study in Princeton. Since 2011, he has been a faculty member at Cambridge University’s Department of Applied Mathematics and Theoretical Physics (DAMTP), before being appointed to a Chair for Theoretical Cosmology at the University of Amsterdam in 2015. Baumann’s research has been recognized by numerous awards, including a Jade Mountain Visiting Professorship at National Taiwan University and the invitation to speak in this first annual Chin Yu Lecture.
Video
Video Link
Mar 9, 2021
Heng-Liang Wu, Center for Condensed Matter Sciences, National Taiwan University
Host:
Yang-Fang Chen
Time: 2:20 pm
-3:20 pm
Place: Room 204,
CCMS-New Phys. building
Title:
Vibrational Spectroscopy at Electrochemical Interfaces: Electrocatalytic Conversion of CO2 and Lithium-Sulfur Battery
Abstract
Electrochemical energy conversion and storage processes occurred in the electrolyzer and battery devices play a vital role in the development of sustainable energy technologies. The predominant mechanism of the devices involves the charge transfer and various redox reactions on the solid-liquid interfaces which affect the reactivity and performance. In order to reveal the reaction mechanism, in-situ vibrational spectroscopy techniques such as Raman and surface-enhanced infrared absorption spectroscopy are the powerful tools for examining reaction intermediates on the solid-liquid interfaces. In this talk, we report on our use of in-situ SEIRAS to investigate the electrochemical CO2 reduction mechanism over the Cu electrocatalysts and in situ Raman spectroscopy to study the effect of electrolyte on the sulfur reduction mechanism in lithium-sulfur battery. Various in situ techniques were used to provide the complementary information in the energy conversion and storage systems. The reaction mechanism will be discussed in detail.
Brief Bio
Dr. Wu obtained his PhD at Hokkaido University (Japan) in 2013. He worked as a postdoctoral research fellow at University of Illinois at Urbana-Champaign (USA) in 2013-2016. Then he joined the faculty at National Taiwan University in 2016. He is now the assistant research fellow in Center for Condensed Matter Sciences. Dr. Wu is dedicated to realizing the electrochemical reaction at solid/liquid and solid/gas interfaces in energy conversion/storage systems. Operando techniques including vibrational spectroscopy (Surface-enhanced IR, Raman, SFG) and X-ray spectroscopy are used for understanding the reactions at the molecular scale. In his works, the main subjects are (1) molecular adsorption at interfaces and (2) mechanism of electro-catalysis and battery reaction.
Mar 16, 2021
Chi-Feng Pai, Department of Materials Science and Engineering,
National Taiwan University
Host:
Yang-Fang Chen
Time: 2:20 pm
-3:20 pm
Place: Room 204,
CCMS-New Phys. building
Title:
The 2nd Renaissance of Spintronics - From spin-transfer torque to spin-orbit torque MRAM
Abstract
The second generation magnetoresistive random access memory (MRAM), which employs the physics of spin-transfer torque (STT) and the nature of spin angular momentum of itinerant electrons, is now in mass production by major foundries such as TSMC and Samsung. In this talk, I will go through the basics of spin transfer torque and how it led to the second renaissance of spintronics as well as the invention of STT-MRAM. The physics and the engineering perspectives of future spintronic devices that utilize the spin-orbit torques (SOTs) will also be discussed.
Brief Bio
Prof. Chi-Feng Pai received his Ph.D. degree in Applied Physics from Cornell University in 2015. His research on the giant spin Hall effect in various materials systems led to the invention of spin-orbit torque MRAM. He then joined Department of Materials Science and Engineering at Massachusetts Institute of Technology as postdoctoral research associate. From 2016 to 2020, he served as assistant professor at Department of Materials Science and Engineering of National Taiwan University (NTU). He is currently associate professor at NTU and consulting research fellow at Industrial Technology Research Institute (ITRI), Taiwan. He is the recipient of Young Researcher Award of Asian Union of Magnetic Society (AUMS) in 2016, Ta-You Wu Memorial Award of Ministry of Science and Technology (MOST, Taiwan) in 2020, and Young Researcher Award of Taiwan Semiconductor Industry Association (TSIA) in 2020.
Video
Video Link
Mar 23, 2021
Pisin Chen, Department of Physics,
National Taiwan University
Host:
Yang-Fang Chen
Time: 2:20 pm
-3:20 pm
Place: Room 204,
CCMS-New Phys. building
Title:
Everything you want to know about black holes— 2020 Nobel Prize in Physics, etc.
黑洞無所不談— 從2020諾貝爾物理學獎說起
Abstract
The 2020 Nobel Prize in Physics was awarded to Roger Penrose “for the discovery that black hole formation is a robust prediction of the general theory of relativity”, the other half to Reinhard Genzel and Andrea Ghez “for the discovery of a supermassive compact object at the center of our galaxy.” Adding the LIGO’s first observation of gravitational waves induced by coalescing binary black holes in 2016, which resulted in the recognition by the 2017 Nobel Prize, and the Event Horizon Telescope (EHT)’s observation of supermassive black hole in the galaxy M87, the existence of black holes, both theoretically and experimentally, are now firmly established. What exactly is a black hole? How would its existence in the universe affect its evolution? Black holes are fertile testing grounds for the future development of modified and/or quantum gravity theories. Would Hawking radiation result in the complete evaporation of a black hole, or perhaps leave behind a remnant? Would it render the loss of information? If not, how would the information be preserved? This question has bothered theoretical physicists for more than 40 years without a consensus. So would experimental means be able to shed some lights on this paradox? In this talk, which will be pedagogical and colloquial, we will review the history, the present state, and the future prospect of black hole physics.
Brief Bio
Pisin Chen is a NTU Distinguished Chair Professor, the NTU C. C. Leung Chair Professor of Cosmology, and the Director of the NTU Leung Center for Cosmology and Particle Astrophysics (LeCosPA), which he founded in 2007. In 2000 he initiated the Pehong and Adele Chen (later renamed Kavli) Institute for Particle Astrophysics and Cosmology at Stanford University, and has since been its permanent member. He was a Visiting Professor at Ecole Polytechnique, France, in 2014 and at the University of Tokyo in 2015. Prof. Chen received his PhD from UCLA in theoretical particle physics under J. J. Sakurai. He then switched to plasma physics as a postdoc under John Dawson in the mid 1980s. Together, they proposed the concept of ‘Plasma Wakefield Accelerator’, which has become an area of active research worldwide. In early 1990s, inspired by the COBE discovery of the CMB anisotropy, he switched his research focus again, to cosmology, particle astrophysics, and gravity. He is one of the early proponents of the radio detection of ultra-high energy cosmic rays and neutrinos. In 2009, he initiated the international Askaryan Radio Array (ARA) Observatory, which became ROC’s first major science project at the South Pole. In 2015, he launched the TAROGE observatory in the east coast of Taiwan, which put Taiwan on the world map of ultra-high energy cosmic ray and neutrino observatories. He is an APS Fellow since 1994, a two-time recipient of Gravity Research Foundation’s Annual Essay Competition Awards (1995, 2001), and a Laureate of the 2018 Blaise Pascal Chair, bestowed by the government of Ile de France, for his inception of flying plasma mirror as an analog black hole to investigate the information loss paradox.
Video
Video Link
Mar 30, 2021
Hao-Wu Lin, Department of Materials Science and Engineering,
National Tsing Hua University, Taiwan
Host:
Yang-Fang Chen
Time: 2:20 pm
-3:20 pm
Place: Room 204,
CCMS-New Phys. building
Title:
Lead Halide Perovskite Beyond Solar Cells: New Applications in Quantum Emitter and Neuromorphic Computing
Abstract
Halide perovskites have attracted great attention as promising materials especially for solar energy conversion. In recent years, we have developed the unique all vacuum deposition technique for perovskite thin films and devices fabrication and new spray synthesis method for making highly luminescent perovskite quantum dots. In this talk, I will more focus on our wonderful journey from photovoltaic devices to new exciting applications of quantum emitters and neuromorphic computing. Excellent novel properties are found in these halide perovskites that make them one of the most promising material systems for such emerging technologies.
Brief Bio
Professor Hao-Wu Lin graduated from National Taiwan University in 2002 with a bachelor degree in electrical engineering. He received his Ph.D. degree from graduate institute of photonics and optoelectronics, National Taiwan University in 2007. After his Ph.D. study and military service, he joined AU Optronics Corp. for research and development on organic light emitting displays. In 2009, he joined the faculty of National Tsing-Hua University in the department of materials science and engineering and now act as a full professor and the group leader of advanced optoelectronic materials laboratory (AOML, http://mx.nthu.edu.tw/~hwlin/). His current research interests include organic and halide perovskite semiconductors for optoelectronic and electronic devices, next-generation photovoltaics, flat panel displays, quantum emitters, hardware-based neuromorphic computing, and nano science and technologies.
Apr 13, 2021
May 11, 2021
May 18, 2021
June 1, 2021
