Observation of topological locally resonate and Bragg edge modes in a two-dimensional slit-typed sonic crystal

摘要

We present the design, analysis, fabrication and testing of the two topological edge states in a sub-wavelength two-dimensional sonic crystal (SC) system based on the mechanism of local resonance and Bragg scattering. The slit-typed SC consists of artificial meta-molecules embedded in the air with a triangle lattice, which is designed by introducing three coupled Helmholtz resonators. Frequency-tunable edge modes are obtained by adjusting the slit of the structure. Experimental results agree well with the theoretical calculations. Our works may enrich the designing of acoustic topological insulators in a sub-wavelength region and have potential applications in acoustic wave manipulation in general. (C) 2019 The Japan Society of Applied Physics