Non-Hermitian band topology with generalized inversion symmetry
Non-Hermitian band topology with generalized inversion symmetry
复制标题
DOI：
10.1103/physrevb.103.205205
复制
发表时间：
2021-03
影响因子：
3.7
通讯作者：
R. Okugawa;R. Takahashi;Kazuki Yokomizo
中科院分区：
文献类型：
--
作者：
R. Okugawa;R. Takahashi;Kazuki Yokomizo
非厄米特皮肤效应和例外点是以整数缠绕数为特征的拓扑现象。在这项研究中，我们给出的方法，理论上检测皮肤效应和例外点，通过推广反演对称。反演对称性的推广是非厄米特系统所独有的。我们表明，奇偶的缠绕数可以确定从能量特征值的反转不变的动量广义反转对称时。给出的缠绕数的简单表达式使我们能够方便地分析非厄米特带中的表皮效应和例外点。我们还演示了（二阶）皮肤效应和例外点的方法，通过使用格模型。
Non-Hermitian skin effects and exceptional points are topological phenomena characterized by integer winding numbers. In this study, we give methods to theoretically detect skin effects and exceptional points by generalizing inversion symmetry. The generalization of inversion symmetry is unique to non-Hermitian systems. We show that parities of the winding numbers can be determined from energy eigenvalues on the inversion-invariant momenta when generalized inversion symmetry is present. The simple expressions for the winding numbers allow us to easily analyze skin effects and exceptional points in non-Hermitian bands. We also demonstrate the methods for (second-order) skin effects and exceptional points by using lattice models.