Topological band theory for non-Hermitian systems from the Dirac equation
Topological band theory for non-Hermitian systems from the Dirac equation
复制标题
来自狄拉克方程的非厄米系统的拓扑能带理论
DOI：
10.1103/physrevb.100.054105
复制
发表时间：
2019-08-15
影响因子：
3.7
通讯作者：
Nori, Franco
中科院分区：
文献类型：
--
作者：
Ge, Zi-Yong;Zhang, Yu-Ran;Nori, Franco
我们确定和研究两类非厄米特系统，即，从量子场论的角度来看，一个是由洛伦兹对称破坏（LSV）引起的，另一个是由具有洛伦兹不变性的复质量（CM）引起的。阐明了这两类非厄米系统中体边界对应的破坏机制和恢复途径。具有LSV的非厄米特系统表现出非厄米特趋肤效应，其拓扑相位可以通过非紧U（1）规范变换映射到厄米特系统来表征。相反，对于非厄米系统，CM不存在非厄米集肤效应。此外，传统的体边界对应关系在该（CM）系统中成立。我们还考虑了一个一般的非厄米特系统的存在下，LSV和CM，我们推广了它的体边界对应。
We identify and investigate two classes of non-Hermitian systems, i.e., one resulting from Lorentz-symmetry violation (LSV) and the other from a complex mass (CM) with Lorentz invariance, from the perspective of quantum field theory. The mechanisms to break, and approaches to restore, the bulk-boundary correspondence in these two types of non-Hermitian systems are clarified. The non-Hermitian system with LSV shows a non-Hermitian skin effect, and its topological phase can be characterized by mapping it to the Hermitian system via a non-compact $U(1)$ gauge transformation. In contrast, there exists no non-Hermitian skin effect for the non-Hermitian system with CM. Moreover, the conventional bulk-boundary correspondence holds in this (CM) system. We also consider a general non-Hermitian system in the presence of both LSV and CM, and we generalize its bulk-boundary correspondence.