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arXiv · 2407.07136

Non-Hermitian $\mathbb{Z}_4$ skin effect protected by glide symmetry

Sho Ishikawa·Tsuneya Yoshida
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Abstract

Although nonsymmorphic symmetry protects $\mathbb{Z}_4$ topology for Hermitian systems, non-Hermitian topological phenomena induced by such a unique topological structure remain elusive. In this paper, we elucidate that systems with glide symmetry exhibit non-Hermitian skin effects (NHSE) characterized by $\mathbb{Z}_4$ topology. Specifically, numerically analyzing a two-dimensional toy model, we demonstrate that the $\mathbb{Z}_4$ topology induces the NHSE when the topological invariant takes $\nu=1,2$. Furthermore, our numerical analysis demonstrates that the NHSE is destroyed by perturbations preserving the relevant symmetry when the $\mathbb{Z}_4$-invariant takes $\nu=4$.

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Sho Ishikawa, Tsuneya Yoshida. 2024-07-09. Non-Hermitian $\mathbb{Z}_4$ skin effect protected by glide symmetry. https://doi.org/10.1103/physrevb.110.115301

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