演讲人： Xiong-Jun Liu Peking University
时间： 2019-05-20 11:00-2019-05-20 12:00
地点：FIT 1-222
内容：

Topological phase of matter is a main stream of research in condensed matter physics, with the characterization having been mainly developed based on equilibrium theory. In comparison, non-equilibrium dynamics induced by quenching a quantum system may carry information of both the initial phase and post-quench target phase. In this talk I will introduce how to characterize topological quantum phases by far-from-equilibrium quantum dynamics induced by quench, and further explore dynamically both the topology and symmetry-breaking order in correlated topological system. In free-fermion topological phases, we show a dynamical bulk-surface correspondence relates the dD bulk topology to dynamical topological pattern emerging in the (d-1)D band-inversion surfaces (BISs) in momentum space, similar to the well-known bulk-boundary correspondence in the real space. In the interacting regime, the quantum pseudospin dynamics is shown to follow a microscopic Landau-Lifshitz-Gilbert equation and exhibit robust universal behaviors on the BISs, from which the nontrivial topology and magnetic orders can be extracted. In particular, the topology can be characterized by an emergent topological pattern of quench dynamics on BISs, which is robust against dephasing and heating induced by interactions; the pre-quench symmetry-breaking orders can be read out from a universal scaling behavior of the quench dynamics emerging on the BIS. These results may show insights into the exploration of novel correlation physics with nontrivial topology by quench dynamics.

个人简介:

刘雄军教授2011年博士毕业于德州A&M大学物理系。2011至2014年分别在马里兰大学凝聚态物理中心和联合量子研究所，香港科大高等研究院和麻省理工学院从事博士后研究。他于2014年9月加入北京大学量子材料科学中心任研究员。2018年7月获得终身长聘职位，同年8月获得国家杰青资助，2019年1月晋升为正教授。刘雄军教授长期在拓扑物相和超冷原子量子模拟领域开展研究。他在人工规范场量子模拟，拓扑超导领域做出系列工作；尤其推动近些年人工自旋轨道耦合、拓扑量子模拟方向的理论和实验发展。研究工作多以通讯作者或一作发表在Science，Science子刊，Nature子刊，PRL，PRX等期刊上。他目前的主要研究兴趣集中在拓扑超导，人工规范场量子模拟，非平衡拓扑量子系统，强关联拓扑物相等方面。