At the invitation of the school of physical science and technology, Prof. Ying Liu of Pennsylvania State University came to our school for academic exchange, and delivered an academic report titled "Superconductivity in bulk and mesoscopic Sr2RuO4" in the conference room 437 of Xingjian building at 10 AM on June 5, 2019. Teachers and students in related fields attended the academic report.
Ying Liu, professor of physics at Pennsylvania State University and Hongwen Professor of Physics at Shanghai Jiao Tong University (part-time), received his BS degree from Peking University in 1982. He earned a MS degree, under the direction of Professor Zhao-Qing Zhang at Institute of Physics, Chinese Academy of Sciences, Beijing in 1984. Prof. Liu did his Ph. D. thesis research under the direction of Professor Allen M. Goldman at University of Minnesota, and received his Ph.D. degree in 1991. After three-year postdoctoral research at University of Colorado, Boulder, Prof. Liu joined the faculty of Department of Physics of the Pennsylvania State University in 1994, becoming tenured full professor in 2005. His research has focused on the study of low-dimensional and unconventional superconductors, in particular, odd-parity, spin-triplet superconductor Sr2RuO4. He also worked on graphene, topological insulators, 2D crystals of transition metal oxides and chalcogenides, as well as strongly correlated electronic systems. Professor Liu received an NSF Career Award in 1997 and was selected as a fellow of the American Physical Society in 2006. He was awarded an Outstanding Young Investigator (Type B) award from National Science Foundation of China and a Chang Jiang Lecturer Professorship from Chinese Ministry of Education.
In this report, professor Liu first introduced the research status of the superconductor Sr2RuO4. He points out that although there are theoretical predictions that the superconductor Sr2RuO4 is an odd-parity, spin-triplet superconductor, the precise pairing state realized in Sr2RuO4 is yet to be resolved. His work has focused on the transport and tunneling measurements on Sr2RuO4, in particular, the Josephson effect and related phase-sensitive measurements detecting the symmetry of the orbital part of the Cooper pair wave function. In particular, his work on doubly connected mesoscopic cylinders of Sr2RuO4 prepared by a combination of conventional and unconventional nanofabrication techniques is very interesting. His work was aimed at detecting evidence for the half-flux-quantum state using a different set of measurements and clarifying the effect of the in-plane magnetic field that was shown to be necessary.
After the end of the report, teachers and students responded very warmly, and raised a lot of questions about the superconductor Sr2RuO4. Professor Liu carried out a detailed solution and discussion, and welcomed students to further contact and exchange.