Pure skin effect obeying power partition in directed graphs

Fuente: arXiv
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Main Authors: Liu, Wenwen, You, Oubo, Min, Bumki, Zhang, Shuang
Format: Preprint
Published: 2024
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_version_ 1866909178325368832
author Liu, Wenwen
You, Oubo
Min, Bumki
Zhang, Shuang
author_facet Liu, Wenwen
You, Oubo
Min, Bumki
Zhang, Shuang
contents Non-Hermitian physics has received great attention recently. In particular, band structures in non-Hermitian systems can be engineered to exhibit various topological effects. Among them, one of the most intriguing phenomena is the non-Hermitian skin effect (NHSE). Here, we investigate NHSE in systems featuring directed chains or directed graphs, where the arrows denote the directions of the non-reciprocal hopping between neighbouring nodes. We show that the systems exhibit pure skin modes with non-oscillatory wavefunctions, in contrast to previously studied NHSE. Interestingly, the sum of the decay constants along different directions for each skin mode obeys a power partition rule, i.e. their sum is a fixed value and the value of each constant only depends on the ratio between the non-reciprocal hopping parameters and is independent of detailed graph configurations. Such Pure Skin Effect (PSE) can be explained by using a generalized method for solving the Generalized Brillouin-zone with multiple bulk states.
format Preprint
id arxiv_https___arxiv_org_abs_2404_14727
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Pure skin effect obeying power partition in directed graphs
Liu, Wenwen
You, Oubo
Min, Bumki
Zhang, Shuang
Quantum Physics
Applied Physics
Optics
Non-Hermitian physics has received great attention recently. In particular, band structures in non-Hermitian systems can be engineered to exhibit various topological effects. Among them, one of the most intriguing phenomena is the non-Hermitian skin effect (NHSE). Here, we investigate NHSE in systems featuring directed chains or directed graphs, where the arrows denote the directions of the non-reciprocal hopping between neighbouring nodes. We show that the systems exhibit pure skin modes with non-oscillatory wavefunctions, in contrast to previously studied NHSE. Interestingly, the sum of the decay constants along different directions for each skin mode obeys a power partition rule, i.e. their sum is a fixed value and the value of each constant only depends on the ratio between the non-reciprocal hopping parameters and is independent of detailed graph configurations. Such Pure Skin Effect (PSE) can be explained by using a generalized method for solving the Generalized Brillouin-zone with multiple bulk states.
title Pure skin effect obeying power partition in directed graphs
topic Quantum Physics
Applied Physics
Optics
url https://arxiv.org/abs/2404.14727