Second-order topological non-Hermitian skin effects
Abstract
Higher-order topology realizes topologically robust corner modes as a manifestation of nontriviality. We theoretically propose non-Hermitian skin effects which stem from second-order topology of chiral-symmetric Hermitian systems. It is found that the skin modes are localized at the corners. We demonstrate two types of second-order topological skin effects by two-dimensional intrinsic and extrinsic second-order topology. The intrinsic second-order topological skin effect is characterized topologically by bulk inversion symmetry as well as chiral symmetry. Meanwhile, the extrinsic second-order topological skin effect occurs from the topological correspondence between the edges and corners. We show that the non-Hermitian skin modes emerge by using a relationship between second-order and conventional first-order topology.
Cite
@article{arxiv.2008.03721,
title = {Second-order topological non-Hermitian skin effects},
author = {Ryo Okugawa and Ryo Takahashi and Kazuki Yokomizo},
journal= {arXiv preprint arXiv:2008.03721},
year = {2021}
}
Comments
11 pages, 3 figures (including Supplemental Material). Discussion added, and figures and typos corrected