标题： 临界非厄米边缘模式 显示英文标题

标题： Critical Non-Hermitian Edge Modes

摘要： 我们揭示了非厄米体系中一种独特的拓扑边缘模式临界现象，称为临界非厄米边缘模式（CNHEM）。具体而言，在热力学极限下，边缘模式的特征向量在无穷小的 onsite 错位扰动下发生不连续跳跃。CNHEM 的出现源于引入的 onsite 错位势与边缘模式之间依赖于系统大小的非互易耦合之间的竞争，并且与例外点（EP）密切相关。随着系统尺寸的增加，边缘模式之间的耦合减弱，而非互易性增强，导致特征向量逐渐趋向 EP。然而，当 onsite 势占主导时，这种减弱的耦合作用有助于特征向量远离 EP。这种临界现象在厄米体系中不存在，因为厄米体系中边缘模式之间的耦合是互易的。 显示英文摘要

摘要： 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.