Nonabelian Ginzburg-Landau Theory for Ferroelectrics
Speaker
Prof. You-Quan Li
Zhejiang University
Abstract

The Ginzburg-Landau theory was introduced to phenomenologically describe the destruction of superconductivity by a magnetic field at the beginning, has brought up much more knowledge beyond the original one as a mean-field theory of thermodynamics states.There the complex order parameter plays an important role. Here we propose a macroscopic theory, by introducing a two-component complex order parameter, to describe the features of ferroelectrics. It is conceptually nonabelian and provides more freedom to reflect interplays between different measurables. Within this theoretical framework, some recently discovered empirical static and time-independent phenomena, such as vortex, anti-vortex, sprial orders  can be obtained as solutions for different gauge potentials.It is expected to bring in a new angle of view with more elucidation than the traditional one that takes the polarization as order parameter.



About the Speaker

Dr. You-Quan Li, (Ph.D.-Physics), now is a distinguished Professor of Physics in the ZIMP and Department of Physics at Zhejiang University. He got his B Sc in physics in 1983, M Sc in theoretical physics in 1986 and Ph. D. in theoretical physics in 1989 at Lanzhou University. Main academic experiences: 1996.06-96.09 Visiting Associate Member, ICTP, Trieste Italy; 1997.02-97.11 Professeur invite, ETH-Lausanne, Switzerland; 1997.12-1998.3 Visiting Scientist, Univ. of Cincinnati, USA; 1999.5-2001.8 AvH-fellow, Inst. Physik, Augsburg Univ., Germany;  2002.1-4 Visiting Scientist, Chinese University of Hong Kong. Research areas: 1986-1996: Quantum group and Yang-Baxter equation, low-dimensional quantum field theory related and classical integrable systems; 1995-2006: Quantum theory for mesoscopic circuits and physics of mesoscopic systems, low-dimensional models in condensed matter physics; quantum process, quantum entanglement and quantum phase transition; 2002-2012: Quantum phenomena in cold atoms; 2007-present: quantum manipulation and fundamentals for quantronics. Currently, Prof. You-Quan Li’s researches focus on novel phenomena in condensed system and their potential applications; quantum simulation and quantum sensing. 



Date&Time
2021-10-12 10:30 AM
Location
Room: A303 Meeting Room
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