Topological transport of GHz surface acoustic wave

Implementation of topological concept to phonon could have large impact on sound manipulation since novel features including low-dissipation, localization, and unidirectionality could be involved. Intensive studies have realized various topological acoustic waveguides, but most of the demonstrations are limited to kHz to MHz soundwaves. Here, we experimentally show GHz topological surface acoustic waves (SAW) using a nano-scaled phononic device and novel imaging technique. Our realization can be useful for superior SAW device for microwave communication.