题目：Observation of individual macroscopic quantum tunneling eventsin superconducting nanowires
地点： 英杰交流中心 阳光大厅
摘要：In quasi-one-dimensional nanowires, superconductivity is destroyed by phase slip events. Phase slips can be caused by thermal activation over a free energy barrier or by quantum tunneling through the barrier. Quantum phase slip (QPS) is an example of macroscopic quantum tunneling. Here, we report the observation of QPS experimentally separated from interference of thermally activated phase slips (TAPS) in aluminum nanowires. This separation between the low temperature QPS and the high temperature TAPS regions is made possible by a phase slip free superconducting region stabilized by the dissipative environment viz. the normal electrodes. Individual QPSs are detected by means of a single-shot voltage measurement protocol, in which they appear as stochastic switching events from the superconducting to the normal state.
主讲人简历：MOSES HUNG-WAI CHAN (陳鴻渭) was born in Xi’an and grew up in Hong Kong. He received his scientific training at Bridgewater College, Virginia (B.A., 1967), Cornell University (Ph.D., 1974) and Duke University (post-doc, 1973-1976). He held teaching positions at the University of Hong Kong (1969–1970) and the University of Toledo (1976–1979) before joining the faculty at the Pennsylvania State University in 1979. He currently holds the title of Evan Pugh Professor of Physics.
Chan’s research centers on low temperature phase transition studies of quantum fluids and solids, superconductivity of nanowires in the one dimensional limit. He has trained 20 Ph.D. and 8 master’s students and sponsored 17 postdoctoral research associates.
He was a recipient of the Guggenheim Fellowship (1986) and the Fritz London Memorial Prize (1996). He is a fellow of the American Physical Society (1987), a member of the National Academy of Sciences (2000), and a fellow of the American Academy of Arts and Sciences (2004) and the American Association for the Advancement of Science (2007).