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arXiv · 2005.13205

Topological Anderson insulators in two-dimensional non-Hermitian disordered systems

Ling-Zhi Tang·Ling-Feng Zhang·Guo-Qing Zhang·Dan-Wei Zhang
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Abstract

The interplay among topology, disorder, and non-Hermiticity can induce some exotic topological and localization phenomena. Here we investigate this interplay in a two-dimensional non-Hermitian disordered Chern-insulator model with two typical kinds of non-Hermiticities, the nonreciprocal hopping and on-site gain-and-loss effects. The topological phase diagrams are obtained by numerically calculating two topological invariants in the real space, which are the disorder-averaged open-bulk Chern number and the generalized Bott index, respectively. We reveal that the nonreciprocal hopping (the gain-and-loss effect) can enlarge (reduce) the topological regions and the topological Anderson insulators induced by disorders can exist under both kinds of non-Hermiticities. Furthermore, we study the localization properties of the system in the topologically nontrivial and trivial regions by using the inverse participation ratio and the expansion of single particle density distribution.

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Ling-Zhi Tang, Ling-Feng Zhang, Guo-Qing Zhang, Dan-Wei Zhang. 2020-05-27. Topological Anderson insulators in two-dimensional non-Hermitian disordered systems. https://doi.org/10.1103/physreva.101.063612

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