畴壁系统中的非厄米趋肤效应  

Non-Hermitian skin effect in a domain-wall system

作　　者：邓天舒 Deng Tian-Shu(Institute for Advanced Study,Tsinghua University,Beijing 100084,China)

机构地区：[1]清华大学高等研究院,北京100084

出　　处：《物理学报》2022年第17期18-31,共14页Acta Physica Sinica

摘　　要：非厄米趋肤效应是近几年非厄米物理研究领域中的热点问题,它揭示了非厄米系统中体态波函数和能谱计算会敏感依赖于边界条件的新奇现象.人们提出广义布里渊区的概念用以刻画非厄米系统中的体态波函数和能带性质.基于广义布里渊区计算的非布洛赫拓扑数可以重新构建非厄米拓扑体边对应关系.然而,过去关于非厄米趋肤效应的讨论主要针对开放边界条件,如果采用畴壁边界条件,广义布里渊区和非布洛赫拓扑数的计算都需要重新考虑.本文综述了近几年关于畴壁边界条件下非厄米趋肤效应的若干研究工作,首先从一般的一维非厄米单带模型出发,推导广义布里渊区方程的一般形式;然后回顾了非厄米SSH(Su-Schieffer-Heeger)模型中广义布里渊区和非布洛赫拓扑数的计算;最后在一维光量子行走的系统中,介绍了实验上非厄米趋肤效应的实现和非厄米拓扑边缘态的探测.The non-Hermitian skin effect is one of the most striking features in non-Hermitian physics.It reveals a novel phenomenon in a non-Hermitian system that the bulk wave function and energy spectrum are sensitively dependent on the boundary conditions.The concept of generalized Brillouin zones has been proposed to characterize bulk wave functions in such systems.Based on generalized Brillouin zones,non-Bloch topological invariants can reconstruct the non-Hermitian bulk-edge correspondence.Previous discussion of the non-Hermitian skin effect mainly focused on open boundary conditions,and the calculation of generalized Brillouin zones needs to be reconsidered under domain-wall boundary conditions.The paper introduces the related researches of the non-Hermitian skin effect in domain-wall systems,including the general form of the generalized Brillouin zone equation in a one-dimensional single-band model,non-Bloch topological invariants in non-Hermitian SSH(Su-Schieffer-Heeger)model,and the experimental realization of the non-Hermitian skin effect in one-dimensional quantum walk system.

关 键 词：畴壁边界条件 非厄米趋肤效应 非布洛赫能带理论 非厄米拓扑体边对应关系 

分 类 号：O469[理学—凝聚态物理]