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

• URL: http://arxiv.org/abs/2005.13205v2
• Date: Wed, 10 Jun 2020 01:23:48 GMT
• Title: Topological Anderson insulators in two-dimensional non-Hermitian disordered systems
• Authors: Ling-Zhi Tang, Ling-Feng Zhang, Guo-Qing Zhang and Dan-Wei Zhang
• Abstract summary: We study the interplay in a non-Hermitian disordered Chern-insulator model with two typical kinds of non-Hermiticities. The nonreciprocal hopping (the gain-and-loss effect) can enlarge (reduce) the topological regions. The topological Anderson insulators induced by disorders can exist under both kinds of non-Hermiticities.
• Score: 1.8057851545459673
• License: http://arxiv.org/licenses/nonexclusive-distrib/1.0/
• 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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