1. Experimental Characterization of Three-Band Braid Relations in Non-Hermitian Acoustic Systems
- Author
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Zhang, Qicheng, Zhao, Luekai, Liu, Xun, Feng, Xiling, Xiong, Liwei, Wu, Wenquan, and Qiu, Chunyin
- Subjects
Condensed Matter - Mesoscale and Nanoscale Physics ,Mesoscale and Nanoscale Physics (cond-mat.mes-hall) ,FOS: Physical sciences ,Applied Physics (physics.app-ph) ,Physics - Applied Physics - Abstract
The nature of complex eigenenergy enables unique band topology to the non-Hermitian (NH) lattice systems. Recently, there has been a fast growing interest in the elusive winding and braiding topologies of the NH single and double bands, respectively. Here, we explore the even more intricate NH multi-band topology and present the first experimental characterization of the three-band braid relations by acoustic systems. Based on a concise tight-binding model, we design a ternary cavity-tube structure equipped with a highly controllable unidirectional coupler, through which the acoustic NH Bloch bands are experimentally reproduced in a synthetic dimension. We identify the NH three-band braid relations from both the perspectives of eigenvalues and eigenstates, including a noncommutative braid relation and a swappable braid relation. Our results could promote the understanding of NH Bloch band topology and pave the way toward designing new devices for manipulating acoustic states., 5 figures
- Published
- 2022