Experimental demonstration of topologically protected efficient sound propagation in an acoustic waveguide network

摘要

Acoustic topological states support sound propagation along the boundary in a one-way direction with inherentrobustness against defects and disorders, leading to the revolution of the manipulation on acoustic waves. Avariety of acoustic topological states relying on circulating fluid, chiral coupling, or temporal modulation havebeen proposed theoretically. However, experimental demonstration has so far remained a significant challenge,due to the critical limitations such as structural complexity and high losses. Here, we experimentally demonstratean acoustic anomalous Floquet topological insulator in a waveguide network. The acoustic gapless edge statescan be found in the band gap when the waveguides are strongly coupled. The scheme features simple structureand high-energy throughput, leading to the experimental demonstration of efficient and robust topologicallyprotected sound propagation along the boundary. The proposal may offer a unique, promising application fordesign of acoustic devices in acoustic guiding, switching, isolating, filtering, etc.