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arXiv · 1908.01172

Non-Hermitian Topological Anderson Insulators

Dan-Wei Zhang·Ling-Zhi Tang·Li-Jun Lang·Hui Yan·Shi-Liang Zhu
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Abstract

Non-Hermitian systems can exhibit unique topological and localization properties. Here we elucidate the non-Hermitian effects on disordered topological systems by studying a non-Hermitian disordered Su-Schrieffer-Heeger model with nonreciprocal hoppings. We show that the non-Hermiticity can enhance the topological phase against disorders by increasing energy gaps. Moreover, we uncover a topological phase which emerges only under both moderate non-Hermiticity and disorders, and is characterized by localized insulating bulk states with a disorder-averaged winding number and zero-energy edge modes. Such topological phases induced by the combination of non-Hermiticity and disorders are dubbed non-Hermitian topological Anderson insulators. We also find that the system has non-monotonous localization behaviour and the topological transition is accompanied by an Anderson transition. These properties are general in other non-Hermitian models.

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Dan-Wei Zhang, Ling-Zhi Tang, Li-Jun Lang, Hui Yan, Shi-Liang Zhu. 2019-08-03. Non-Hermitian Topological Anderson Insulators. https://doi.org/10.1007/s11433-020-1521-9

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