Observation of an acoustic non-Hermitian topological Anderson insulator

• Main Authors: Gu, Zhongming, Gao, He, Xue, Haoran, Wang, Di, Guo, Jiamin, Su, Zhongqing, Zhang, Baile, Zhu, Jie
• Other Authors: School of Physical and Mathematical Sciences
• Format: Article
• Language: English
• Published: 2023
• Subjects: Science::Physics; Topological Anderson Insulator; Topological Edge States
• Online Access: https://hdl.handle.net/10356/171408
• Institution: Nanyang Technological University

The interaction of band topology and disorder can give rise to intriguing phenomena. One paradigmatic example is the topological Anderson insulator, whose nontrivial topology is induced in a trivial system by disorders. In this study, we investigate the effect of purely non-Hermitian disorders on topological systems using a one-dimensional acoustic lattice with coupled resonators. Specifically, we construct a theoretical framework to describe the non-Hermitian topological Anderson insulator phase solely driven by disordered loss modulation. Then, the complete evolution of non-Hermitian disorder-induced topological phase transitions, from an initial trivial phase to a topological Anderson phase and finally to a trivial Anderson phase, is revealed experimentally using both bulk and edge spectra. Interestingly, topological modes induced by non-Hermitian disorders to be immune to both weak Hermitian and non-Hermitian disorders. These findings pave the way for future research on disordered non-Hermitian systems for novel wave manipulation.