Halder Dipendu, Basu Saurabh
Department of Physics, Indian Institute of Technology Guwahati, Guwahati 781039, Assam, India.
J Phys Condens Matter. 2024 May 22;36(33). doi: 10.1088/1361-648X/ad4940.
This work comprehensively investigates the non-Hermitian skin effect (NHSE) in a spinless Bernevig-Hughes-Zhang -like model in one dimension. It is generally believed that a system with non-reciprocal hopping amplitudes demonstrates NHSE. However, we show that there are exceptions, and more in-depth analyses are required to decode the presence of NHSE or its variants in a system. The fascinating aspects of our findings, depending on the inclusion of non-reciprocity in the inter-orbital hopping terms, concede the existence of conventional NHSE or NHSE at both edges and even a surprising absence of NHSE. The topological properties and the (bi-orthogonal) bulk-boundary correspondence, enumerated via computation of the (complex) Berry phase and spatial localization of the edge modes, highlight the topological phase transitions occurring therein. Further, to facilitate a structured discussion of the non-Hermitian model, we split the results intoPTsymmetric and non-PTsymmetric cases with a view to comparing the two.
这项工作全面研究了一维无自旋类Bernevig-Hughes-Zhang模型中的非厄米趋肤效应（NHSE）。人们普遍认为，具有非互易跳跃幅度的系统会表现出NHSE。然而，我们表明存在例外情况，需要更深入的分析来解读系统中NHSE或其变体的存在。我们的研究结果中引人入胜的方面，取决于轨道间跳跃项中是否包含非互易性，包括传统NHSE的存在、两边都存在NHSE，甚至令人惊讶地不存在NHSE。通过计算（复）贝里相位和边缘模式的空间局域化来列举的拓扑性质和（双正交）体边对应关系，突出了其中发生的拓扑相变。此外，为了便于对非厄米模型进行有条理的讨论，我们将结果分为PT对称和非PT对称两种情况，以便对两者进行比较。
