报告题目：Locally-Hermicity: Hermitian chiral boundary states in non-Hermitian topological insulators

报告人：汪晨 副教授（量子交叉研究中心）

报告时间：2021 年 9 月 2 日（周四）15：30

报告地点：线上报告（腾讯会议：736 113 841）

报告摘要：

       While Hermicity is a basic assumption for closed quantum systems, more and more research interests have been focused on non-Hermitian systems for two main reasons: Firstly, non-Hermicity is ubiquitous, and all detectable systems should be non-Hermitian. More importantly, non-Hermicity leads to many unique phenomena absent in Hermitian systems, such as the invalidity of the conventional bulk-boundary correspondence for topological phases, the new energy level statistics, the non-Hermitian skin effect, and the enhanced sensitivity, to name a few. 

      Generally speaking, eigenstates of a non-Hermitian Hamiltonian are non-orthogonal, and their energy spectrum is complex. A pearl of common wisdom is that the real-energy spectrum could emerge if an exceptional point exists. This always happens in non-Hermitian systems with parity-time symmetry. However, such a belief does not work in our recent study. This talk aims to show that a large family of non-Hermitian topological insulators under certain conditions could support Hermitian chiral boundary states of the real-energy spectrum without any exceptional points. Such non-Hermitian topological insulators include two-dimensional Chern insulators, three-dimensional second-order topological insulators, and topological Anderson insulators. 

报告人简介：

       汪晨博士2011年毕业于武汉大学物理科学与技术学院，2016年获得香港科技大学物理学博士。2016年-2019年在电子科技大学电子科学与工程学院从事博士后研究，于2019年加入量子交叉研究中心, 获聘为副教授。主要的研究方向包括：拓扑非平凡系统中的拓扑相变；安德森无序相变；自旋电子学、热激发自旋电子学和拓扑非平凡磁性孤子；以及非线性动力学和混沌等。