报告人：吴洪 讲师（重庆邮电大学）

题目：Breakdown of Non-Bloch Bulk-Boundary Correspondence and Emergent Topology in Floquet Non-Hermitian Systems（周期驱动非厄密体系中非Bloch体边对应的失效和层展的拓扑）

时间：2025年12月18日（周四）下午14：30

腾讯会议ID：197-381-832

联系人：钟寅

报告摘要：

Topological edge states in non-Hermitian systems are generally believed to be robust due to non-Bloch topology. Here, we show that in the Floquet non-Hermitian Su–Schrieffer–Heeger model, infnitesimal symmetry-preserving perturbations can completely destroy edge states, revealing a breakdown of the non-Bloch bulk–boundary correspondence in fnite systems. We trace this fragility to instabilities in the quasienergy spectrum and establish a correspondence between stable zero mode singular states and topologically protected edge states of quasienergies in the thermodynamic limit. Our results formulate a bulk–boundary correspondence intrinsic to Floquet non-Hermitian systems, even in the absence of symmetries. Finally, the presented framework is extended to nonHermitian systems of arbitrary dimensionality and distinct topological classifcations, thereby enabling a general derivation of the bulk-boundary correspondence. It supplies a useful way to explore non-Hermitian Floquet topological phases.

非厄密体系中的拓扑边界态被广泛认为因非Bloch拓扑而显得稳定。我们对周期驱动的非厄密Su-Schrieffer-Heeger模型的研究表明无穷小的对称保留扰动能完全摧毁边界态，这表明有限体系中非Bloch体边对应的失效。我们发现这种易碎性来源于准能谱的不稳定性并建立稳定的零模奇异态和热力学极限下拓扑保护边界态的对应。我们的结果给出了周期驱动非厄密体系固有的体边对应。最后，当前的框架可以扩展到任意维度的非厄密体系以及不同的拓扑分类，有助于获得一般情况下的体边对应。

个人简介：

吴洪，2023年毕业于兰州大学，同年入职重庆邮电大学，讲师，目前主持国家自然科学基金一项，省部级项目两项。目前主要研究非厄米物态，在Communication physics、Physical Review B发表论文10余篇。