Time: 14:00pm, Nov. 29 (Fri.), 2019

Venue: Rm. S401 Kavli ITS meeting room, UCAS Teaching Building [View Map]

Speaker: Wei-Qiang Chen (SUSTC)

Abstract:

Topological phases in non-Hermitian systems have become a fascinating subject recently. In this paper, we attempt to classify topological phases in 1D interacting non-Hermitian systems. We begin with the non-Hermitian generalization of Su-Schrieffer-Heeger(SSH) model and discuss its many body topological Berry phase, which is well defined for any interacting quasi-Hermitian systems(non-Hermitian systems that have real energy spectrum). We then demonstrate that the classifications of topological phases for quasi-Hermitian systems are exactly the same as their Hermitian counterparts. Moreover, we find that unitarity can even emerge for fixed point partition function describing topological phases in 1D non-Hermitian systems with local interactions. Thus we conjecture that for generic 1D interacting non-Hermitian systems, the classification of topological phases are exactly the same as Hermitian systems.

About the speaker: 

陈伟强，2000年本科毕业于清华大学物理系，2006年博士毕业于清华大学高等研究院。2006-2008年在香港大学做博士后研究，2008-2011年在香港大学任职研究助理教授。2011年起任南方科技大学副教授，2012年入选中组部第二批青年千人。主要从事凝聚态理论特别是强关联系统的理论研究，主要研究方向包括，非常规超导电性，拓扑物态（包括拓扑序，对称保护拓扑序等等），拓扑相变，以及利用张量网络方法模拟强关联系统。