Exact Solutions Disentangle Higher-Order Topology in 2D Non-Hermitian Lattices

Fuente: arXiv
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Main Authors: Li, Lingfang, Wei, Yating, Wu, Gangzhou, Ruan, Yang, Chen, Shihua, Lee, Ching Hua, Ni, Zhenhua
Format: Preprint
Published: 2024
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_version_ 1866915190379905024
author Li, Lingfang
Wei, Yating
Wu, Gangzhou
Ruan, Yang
Chen, Shihua
Lee, Ching Hua
Ni, Zhenhua
author_facet Li, Lingfang
Wei, Yating
Wu, Gangzhou
Ruan, Yang
Chen, Shihua
Lee, Ching Hua
Ni, Zhenhua
contents We report the exact closed-form solutions for higher-order topological states as well as explicit energy-spectrum relationships in two-dimensional (2D) non-Hermitian multi-orbital lattices with generalized boundary conditions. These analytical solutions unequivocally confirm that topological edge states in a 2D non-Hermitian system which feature point-gap topology must undergo the non-Hermitian skin effect along the edge. Under double open boundary conditions, the occurrence of the non-Hermitian skin effect for either topological edge states or bulk states can be accurately predicted by our proposed winding numbers. We unveil that the zero-energy topological corner state only manifests itself on a corner where two nearby gapped edge states intersect, and thus can either disappear completely or strengthen drastically due to the non-Hermitian skin effect of gapped topological edge states. Our analytical results offer direct insight into the non-Bloch band topology in two or higher dimensions and trigger experimental investigations into related phenomena such as quadrupole topological insulators and topological lasing.
format Preprint
id arxiv_https___arxiv_org_abs_2410_15763
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Exact Solutions Disentangle Higher-Order Topology in 2D Non-Hermitian Lattices
Li, Lingfang
Wei, Yating
Wu, Gangzhou
Ruan, Yang
Chen, Shihua
Lee, Ching Hua
Ni, Zhenhua
Optics
Other Condensed Matter
We report the exact closed-form solutions for higher-order topological states as well as explicit energy-spectrum relationships in two-dimensional (2D) non-Hermitian multi-orbital lattices with generalized boundary conditions. These analytical solutions unequivocally confirm that topological edge states in a 2D non-Hermitian system which feature point-gap topology must undergo the non-Hermitian skin effect along the edge. Under double open boundary conditions, the occurrence of the non-Hermitian skin effect for either topological edge states or bulk states can be accurately predicted by our proposed winding numbers. We unveil that the zero-energy topological corner state only manifests itself on a corner where two nearby gapped edge states intersect, and thus can either disappear completely or strengthen drastically due to the non-Hermitian skin effect of gapped topological edge states. Our analytical results offer direct insight into the non-Bloch band topology in two or higher dimensions and trigger experimental investigations into related phenomena such as quadrupole topological insulators and topological lasing.
title Exact Solutions Disentangle Higher-Order Topology in 2D Non-Hermitian Lattices
topic Optics
Other Condensed Matter
url https://arxiv.org/abs/2410.15763