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arXiv · 1801.07942

Experimental Realization of Acoustic Chern Insulator

Yifan Zhu·Yugui Peng·Xudong Fan·Jing Yang·Bin Liang·Xuefeng Zhu·Jianchun Cheng
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Abstract

Topological insulators are new states of matter in which the topological phase originates from symmetry breaking. Recently, time-reversal invariant topological insulators were demonstrated for classical wave systems, such as acoustic systems, but limited by inter-pseudo-spin or inter-valley backscattering. This challenge can be effectively overcome via breaking the time-reversal symmetry. Here, we report the first experimental realization of acoustic topological insulators with nonzero Chern numbers, viz., acoustic Chern insulator (ACI), by introducing an angular-momentum-biased resonator array with broken Lorentz reciprocity. High Q-factor resonance is leveraged to reduce the required speed of rotation. Experimental results show that the ACI featured with a stable and uniform metafluid flow bias supports one-way nonreciprocal transport of sound at the boundaries, which is topologically immune to the defect-induced scatterings. Our work opens up opportunities for exploring unique observable topological phases and developing practical nonreciprocal devices in acoustics.

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Yifan Zhu, Yugui Peng, Xudong Fan, Jing Yang, Bin Liang, Xuefeng Zhu, Jianchun Cheng. 2018-01-24. Experimental Realization of Acoustic Chern Insulator. https://doi.org/10.1103/physrevlett.122.014302

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