Non-Hermitian pseudo mobility edge in a coupled chain system

Fuente: arXiv
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Main Authors: Mu, Sen, Zhou, Longwen, Li, Linhu, Gong, Jiangbin
Format: Preprint
Published: 2021
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_version_ 1866913073469587456
author Mu, Sen
Zhou, Longwen
Li, Linhu
Gong, Jiangbin
author_facet Mu, Sen
Zhou, Longwen
Li, Linhu
Gong, Jiangbin
contents In this work, we explore interesting consequences arising from the coupling between a clean non-Hermitian chain with skin localization and a delocalized chain of the same length under various boundary conditions (BCs). We reveal that in the ladder with weak rung coupling, the nonHermitian skin localization could induce a pseudo mobility edge in the complex energy plane, which separates states with extended and localized profiles yet allowing unidirectional transport of signals. We also demonstrate the gradual takeover of the non-Hermitian skin effect in the entire system with the increase of the rung coupling under conventional open BC. When taking open BC for the nonHermitian chain and periodic BC for the other, it is discovered that a quantized winding number defined under periodic BC could characterize the transition from the pseudo mobility edge to the trivial extended phases, establishing a "bulk-defect correspondence" in our quasi-1D non-Hermitian system. This work hence unveils more subtle properties of non-Hermitian skin effects and sheds light on the topological nature of the non-Hermitian localized modes in the proximity to systems with dissimilar localization properties.
format Preprint
id arxiv_https___arxiv_org_abs_2111_11914
institution arXiv
publishDate 2021
record_format arxiv
spellingShingle Non-Hermitian pseudo mobility edge in a coupled chain system
Mu, Sen
Zhou, Longwen
Li, Linhu
Gong, Jiangbin
Mesoscale and Nanoscale Physics
Statistical Mechanics
Quantum Physics
In this work, we explore interesting consequences arising from the coupling between a clean non-Hermitian chain with skin localization and a delocalized chain of the same length under various boundary conditions (BCs). We reveal that in the ladder with weak rung coupling, the nonHermitian skin localization could induce a pseudo mobility edge in the complex energy plane, which separates states with extended and localized profiles yet allowing unidirectional transport of signals. We also demonstrate the gradual takeover of the non-Hermitian skin effect in the entire system with the increase of the rung coupling under conventional open BC. When taking open BC for the nonHermitian chain and periodic BC for the other, it is discovered that a quantized winding number defined under periodic BC could characterize the transition from the pseudo mobility edge to the trivial extended phases, establishing a "bulk-defect correspondence" in our quasi-1D non-Hermitian system. This work hence unveils more subtle properties of non-Hermitian skin effects and sheds light on the topological nature of the non-Hermitian localized modes in the proximity to systems with dissimilar localization properties.
title Non-Hermitian pseudo mobility edge in a coupled chain system
topic Mesoscale and Nanoscale Physics
Statistical Mechanics
Quantum Physics
url https://arxiv.org/abs/2111.11914