近日，中南大学罗文琛团队研究了缺陷与非厄米趋肤效应之间的相互作用。相关论文于2025年9月24日发表在《物理评论A》杂志上。

非厄米趋肤效应（NHSE）是一种有趣的现象，在这种现象中，大量的体特征态局域化在具有非互易跳变的非厄米系统的边界上。

研究组分析了这种效应与一维非互易晶格中的缺陷之间的相互作用。他们表明，NHSE和缺陷的相互作用是尺寸相关的。研究组证明了一类新的混合趋肤缺陷状态在有限尺寸的系统由皮肤和缺陷状态之间的耦合。接下来，他们基于非互易SSH构型，研究具有时间反演对称性的拓扑非平凡晶格中的单个缺陷。通过揭示拓扑非平凡缺陷态与非厄米性之间的竞争机制，研究组发现了从拓扑非平凡缺陷态向趋肤态的转变。此外，该研究表明降低缺陷强度可引发从平凡缺陷态到趋肤态的相变。该工作深化了人们对缺陷与非厄米趋肤效应相互作用机制的理解，尤其揭示了周期性边界条件下含缺陷系统能谱研究的重要性。

附：英文原文

Title: Interplay between defects and the non-Hermitian skin effect

Author: Yin Huang, Wenna Zhang, Yu Zhou, Yuecheng Shen, Georgios Veronis, Wenchen Luo

Issue&Volume: 2025/09/24

Abstract: The non-Hermitian skin effect (NHSE) is an intriguing phenomenon in which an extensive number of bulk eigenstates localize at the boundaries of a non-Hermitian system with nonreciprocal hoppings. Here, we study the interplay of this effect and a defect in nonreciprocal one-dimensional lattices. We show that the interplay of the NHSE and defects is size-dependent. We demonstrate a novel class of hybrid skin-defect states in finite-size systems resulting from the coupling between the skin and defect states. Next, we consider a single defect in a topologically nontrivial lattice with time-reversal symmetry based on the nonreciprocal Su-Schrieffer-Heeger configuration. We unveil how topologically nontrivial defect states and non-Hermiticity interplay by competing with each other, exhibiting a transition from topologically nontrivial defect states to skin states. In addition, we show that decreasing the defect strength can result in a transition from trivial defect states to skin states. Our work promotes the understanding of the interplay between defects and the NHSE and especially the importance of the energy spectra of the system with the defect under periodic boundary conditions.

DOI: 10.1103/622m-d2q6

Source: https://journals.aps.org/pra/abstract/10.1103/622m-d2q6