论文标题
非铁皮皮肤效应边缘
Non-Hermitian skin effect edge
论文作者
论文摘要
在过去的几年中，非铁皮皮肤效应（NHSE）是一种在非热式系统中进行深入研究的独特现象。在这项工作中，我们通过在一维晶格中引入最近的邻居跳跃，讨论NHSE的能量依赖性。在开放边界条件（OBC）下，NHSE的方向逆转为系统的特征力，横扫某些临界能量。为了表征这种现象，我们介绍了非铁皮皮肤效应边缘的概念，该概念将OBC光谱中晶格的相对端的特征状态分开。我们发现皮肤效应边缘由周期性边界条件（PBC）的频谱中的自我交流确定，这是拓扑数，因为PBC频谱的绕组数在越过时会改变符号。此外，当自身交流通过调整系统参数合并为单点时，NHSE边缘将消失。我们的工作揭示了NHSE和非型型跳动在非富米系统中的复杂相互作用。
Non-Hermitian skin effect (NHSE) is a unique phenomenon studied intensively in non-Hermitian systems during the past few years. In this work, we discuss the energy dependence of NHSE by introducing nonreciprocity beyond the nearest-neighboring hopping in the one-dimensional lattices. The direction of NHSE reverses as the eigenenergy of the system under open boundary conditions (OBCs) sweeps across some critical energies. To characterize such a phenomenon, we introduce the concept of non-Hermitian skin effect edges, which separate the eigenstates localized at opposite ends of the lattice in the OBC spectrum. We find the skin effect edges are determined by the self-intersections in the spectrum under periodic boundary conditions (PBCs), which are topological as the winding number of the PBC spectrum changes sign when crossing them. Moreover, the NHSE edges will disappear when the self-intersections merge into a single point by tuning the system parameters. Our work reveals the intricate interplay between NHSE and nonreciprocal hopping in non-Hermitian systems.
