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arXiv · 2306.08923

Non-Hermitian skin effect enforced by nonsymmorphic symmetries

Yutaro Tanaka·Ryo Takahashi·Ryo Okugawa
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Abstract

Crystal symmetries play an essential role in band structures of non-Hermitian Hamiltonian. In this paper, we propose a non-Hermitian skin effect (NHSE) enforced by nonsymmorphic symmetries. We show that the NHSE inevitably occurs if a two-dimensional non-Hermitian system satisfies conditions derived from the nonsymmorphic symmetry of the doubled Hermitian Hamiltonian. This NHSE occurs in symmetry classes with and without time-reversal symmetry. The NHSE enforced by nonsymmorphic symmetries always occurs simultaneously with the closing of the point gap at zero energy. We also show that such a NHSE can occur in specific three-dimensional space groups with nonsymmorphic symmetries.

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Yutaro Tanaka, Ryo Takahashi, Ryo Okugawa. 2023-06-15. Non-Hermitian skin effect enforced by nonsymmorphic symmetries. https://doi.org/10.1103/physrevb.109.035131

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