论文标题

非铁人SSH模型的特性:PT对称的作用

Properties of the non-Hermitian SSH model: role of PT-symmetry

论文作者

Halder, Dipendu, Ganguly, Sudin, Basu, Saurabh

论文摘要

目前的工作介绍了非苏米特式Su-Schrieffer-Heeger(SSH)模型PT对称和非PPT对称方案的拓扑特性之间的区别。非PPT对称情况在间和细胞内跳跃振幅中以非循环性表示,而具有PT对称性的振幅则由复杂的现场交错电势来建模。特别是,我们研究了特殊点的基因座,绕组数,带状结构,并探索散装 - 边界对应关系(BBC)的崩溃。我们进一步研究了这些情况下可观察到的二聚化强度的相互作用。非PPT对称案例表示一个更熟悉的情况,其中绕组的数字突然通过一半授课而通过调整非重生参数而变化,并证明了BBC的完全分解,从而显示了非甲状化皮肤效应。 PT对称情况的拓扑性质似乎紧随其遗传学类似物,只是它显示出具有复杂(纯粹的)能量谱的不间断(破碎的)区域,而绕组数的另一种变体则表现出连续的行为,这是电势强度的函数,而传统的BBC则保留了电位。

The present work addresses the distinction between the topological properties of PT symmetric and non-PT symmetric scenarios for the non-Hermitian Su-Schrieffer-Heeger (SSH) model. The non-PT symmetric case is represented by non-reciprocity in both the inter- and the intra-cell hopping amplitudes, while the one with PT symmetry is modeled by a complex on-site staggered potential. In particular, we study the loci of the exceptional points, the winding numbers, band structures, and explore the breakdown of bulk-boundary correspondence (BBC). We further study the interplay of the dimerization strengths on the observables for these cases. The non-PT symmetric case denotes a more familiar situation, where the winding number abruptly changes by a half-integer through tuning of the non-reciprocity parameters, and demonstrates a complete breakdown of BBC, thereby showing the non-Hermitian skin effect. The topological nature of the PT symmetric case appears to follow closely to its Hermitian analogue, except that it shows unbroken (broken) regions with complex (purely real) energy spectra, while another variant of the winding number exhibits a continuous behavior as a function of the strength of the potential, while the conventional BBC is preserved.

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