Realization of Gapped and Ungapped Photonic Topological Anderson Insulators.
Realization of Gapped and Ungapped Photonic Topological Anderson Insulators.
复制标题
DOI：
10.1103/physrevlett.132.066602
复制
发表时间：
2024-02
影响因子：
8.6
通讯作者：
Mina Ren;Ye Yu;Bintao Wu;Xin Qi;Yiwei Wang;Xiaogang Yao;Jie Ren;Zhiwei Guo;Haitao Jiang;Hong Chen;Xiong-Jun Liu;Zhigang Chen;Yong Sun
中科院分区：
文献类型：
--
作者：
Mina Ren;Ye Yu;Bintao Wu;Xin Qi;Yiwei Wang;Xiaogang Yao;Jie Ren;Zhiwei Guo;Haitao Jiang;Hong Chen;Xiong-Jun Liu;Zhigang Chen;Yong Sun
人们普遍认为，拓扑非平凡的一维系统在零能量下支持边缘态而不是体态。在这项工作中，我们发现了一个意想不到的情况下，拓扑安德森绝缘体（TAI）相，其中两个体模是退化的零能量，除了退化的边缘模式。我们称之为“无缺口TAI”，以区别于以前已知的缺口TAI。我们的实验实现的间隙和unapped TAIs依赖于耦合的光子谐振器，其中耦合的无序是明智的工程通过调整谐振器之间的间距。通过测量在体和边缘的局部态密度，我们证明了这两种类型的TAI的存在，一起形成一个TAI平台的相图。我们的实验结果得到了理论分析的支持。在无间隙的TAI阶段，我们观察到拓扑边缘状态和本地化的体状态在零能量的稳定共存，突出TAI和传统的拓扑绝缘体之间的区别。
It is commonly believed that topologically nontrivial one-dimensional systems support edge states rather than bulk states at zero energy. In this work, we find an unanticipated case of topological Anderson insulator (TAI) phase where two bulk modes are degenerate at zero energy, in addition to degenerate edge modes. We term this "ungapped TAI" to distinguish it from the previously known gapped TAIs. Our experimental realization of both gapped and ungapped TAIs relies on coupled photonic resonators, in which the disorder in coupling is judiciously engineered by adjusting the spacing between the resonators. By measuring the local density of states both in the bulk and at the edges, we demonstrate the existence of these two types of TAIs, together forming a TAI plateau in the phase diagram. Our experimental findings are well supported by theoretical analysis. In the ungapped TAI phase, we observe stable coexistence of topological edge states and localized bulk states at zero energy, highlighting the distinction between TAIs and traditional topological insulators.