Critical Non-Hermitian Edge Modes

Fuente: arXiv
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Main Authors: Zhou, Kunling, Yang, Zihe, Zeng, Bowen, Hu, Yong
Format: Preprint
Published: 2025
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_version_ 1866911272531918848
author Zhou, Kunling
Yang, Zihe
Zeng, Bowen
Hu, Yong
author_facet Zhou, Kunling
Yang, Zihe
Zeng, Bowen
Hu, Yong
contents We unveil a unique critical phenomenon of topological edge modes in non-Hermitian systems, dubbed the critical non-Hermitian edge modes (CNHEM). Specifically, in the thermodynamic limit, the eigenvectors of edge modes jump discontinuously under infinitesimal on-site staggered perturbations. The CNHEM arises from the competition between the introduced on-site staggered potentials and size-dependent non-reciprocal coupling between edge modes, and are closely connected to the exceptional point (EP). As the system size increases, the coupling between edge modes decreases while the non-reciprocity is enhanced, causing the eigenvectors to gradually collapse toward the EP. However, when the on-site potentials dominate, this weakened coupling assists the eigenvectors to stay away from the EP. Such a critical phenomenon is absent in Hermitian systems, where the coupling between edge modes is reciprocal.
format Preprint
id arxiv_https___arxiv_org_abs_2504_18926
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Critical Non-Hermitian Edge Modes
Zhou, Kunling
Yang, Zihe
Zeng, Bowen
Hu, Yong
Mesoscale and Nanoscale Physics
Quantum Physics
We unveil a unique critical phenomenon of topological edge modes in non-Hermitian systems, dubbed the critical non-Hermitian edge modes (CNHEM). Specifically, in the thermodynamic limit, the eigenvectors of edge modes jump discontinuously under infinitesimal on-site staggered perturbations. The CNHEM arises from the competition between the introduced on-site staggered potentials and size-dependent non-reciprocal coupling between edge modes, and are closely connected to the exceptional point (EP). As the system size increases, the coupling between edge modes decreases while the non-reciprocity is enhanced, causing the eigenvectors to gradually collapse toward the EP. However, when the on-site potentials dominate, this weakened coupling assists the eigenvectors to stay away from the EP. Such a critical phenomenon is absent in Hermitian systems, where the coupling between edge modes is reciprocal.
title Critical Non-Hermitian Edge Modes
topic Mesoscale and Nanoscale Physics
Quantum Physics
url https://arxiv.org/abs/2504.18926