Topological disclination states for surface acoustic waves

Abstract

Surface acoustic waves (SAWs) are widely involved in today's communication and sensing networks. Recent exploration of topological SAWs has provided promising prospects for developing future hybrid SAW devices. In this paper, by designing tight-binding phononic crystals on a semi-infinite substrate, we revealed topological disclination states, i.e., a kind of bound state in topologically condensed matters, for the SAWs. Numerical simulations show that the bound states induced by disclination in the SAW system are more diverse than in previous electromagnetic and mechanical systems. SAW resonances in the disclinations can be efficiently excited by appropriate mechanical stimulation with decent qualities. These states are robust and flexible for design, providing options for future multifunctional and interdisciplinary SAW manipulators, processors, sensors, and other on-chip integrated components.