Frequency Band-Controllable Acoustic Topological Insulators Based on Local Dimensional Coordination

The potential value of acoustic topological insulators is of wide interest because of their special topology-protected edge-state unidirectional transmission properties. In this article, a frequency band-controlled acoustic topological insulator based on local dimensional coordination is designed. It is capable of controlling the unidirectional transmission frequency range by controlling the position of the band gap within a certain range. The energy band structure and eigenmodes are analyzed by using the finite element method. The range of control of the band gap position by the local dimension length is derived. The control of the band gap over the unidirectional propagation frequency is experimentally verified. This work provides a way to precisely control the unidirectional transmission frequency of topology-protected edge states in a specific band, opening up new possibilities for their potential value.