Bulk--boundary correspondence in a non-Hermitian quantum spin-Hall insulator

Chihiro Ishii; Yositake Takane

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arXiv · 2311.13142

Bulk--boundary correspondence in a non-Hermitian quantum spin-Hall insulator

Chihiro Ishii·Yositake Takane

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Abstract

We focus on a scenario of non-Hermitian bulk--boundary correspondence that uses a topological invariant defined in a bulk geometry under a modified periodic boundary condition. Although this has succeeded in describing the topological nature of various one-dimensional non-Hermitian systems, its application to two-dimensional systems has been limited to a non-Hermitian Chern insulator. Here, we adapt the scenario to a non-Hermitian quantum spin-Hall insulator to extend its applicability. We show that it properly describes the bulk--boundary correspondence in the non-Hermitian quantum spin-Hall insulator. A phase diagram derived from the bulk--boundary correspondence is shown to be consistent with spectra of the system under an open boundary condition.

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Chihiro Ishii, Yositake Takane. 2023-11-22. Bulk--boundary correspondence in a non-Hermitian quantum spin-Hall insulator. https://arxiv.org/abs/2311.13142

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