报告题目

Zero and Infinity in Physics (物理中的零与无穷大)

报 告 人

Prof. Q. Charles Su

Illinois State University

报告地点

物理楼中楼215

报告时间

2018年7月11日 (星期四) 10:00-11:00

联 系 人

刘运全 (Tel: 6276 8852)

报告摘要

Dr. Su is a computational and theoretical physicist. His early work focused on what happens when atoms are bombarded with intense laser light, suggesting a surprising region of atomic stability at high laser intensities. This prediction was later verified in the laboratory. He generalized his numerical methodology to study relativistic interactions of charged particles by solving the time-dependent Dirac equation on a space-time grid. As a result of these studies, it has become possible to study the impact of relativistic effects on the spreading of the electron’s spatial density and to visualize the dynamical relevance of its spin. During the last decade, Dr. Su has examined external fields that are strong enough to break down the quantum electrodynamical vacuum to create electron-positron pairs. Computer animations permit some first insight into the creation dynamics with full spacetime resolution. With the help of this computational tool, he and his colleagues have resolved the long-standing problem called the Klein paradox. Recently, his group has focused on how to effectively lower the field threshold to trigger pair creation by designing external electric field configurations with optimal variations in space or in time. Dr. Su and his coworkers have extended their model to investigate the origin of the Coulomb force where electron-proton interactions are facilitated not through an external field but through the exchange of mediating photons between them. Today’s lecture discusses how the concept of infinity helps us to understand the intricate structure of the vacuum and what may cause the vacuum to break down.

报告人简介：After receiving a Bachelor’s of Science from Nankai University, Dr. Q. Charles Su went to the University of Rochester (USA) for his graduate studies through the CUSPEA scholarship program coordinated by Nobel Laureate T.D. Lee of Columbia University. He worked in the field of theoretical Quantum Optics under the guidance of Andrew Carnegie Professor J.H. Eberly and received his PhD in 1991. He performed his postdoctoral research at the Max-Planck Institute for Quantum Optics in Munich, Germany. Dr. Su began his career in Illinois State’s Physics Department in 1994, has held the University Professor honor since 2011 and the Distinguished Professor honor since 2016. He shared the American Physical Society Prize for Faculty Research in an Undergraduate Institution in 2006 with his colleague (Dr. R. Grobe). As a Cotrell Science Scholar, Dr. Su was awarded the Singular Exceptional Endeavor of Discovery Grant by Research Corporation in 2017. He has been PI or Co-PI on research grants issued by the National Science Foundation, the US Department of Energy, Research Corporation and the National Science Foundation-China with a total of grant funding that exceeds 2.5 million dollars. Dr. Su has published more than 170 research articles, and has been invited to present at numerous conferences and research institutions. He was elected a Fellow of the American Physical Society in 2012.