Electrically tunable topological interface states in one-dimensional nanomechanical lattices

Abstract

In optics, combining one-dimensional (1D) topological systems with lasers and nonlinear optics has promoted their rapid development. A 1D acoustic topological system can only achieve single-frequency acoustic waves localization, limiting its practicality. The implementation of tunable and integrated 1D topological systems will improve this situation. Here, we propose an electrically tunable and integrable 1D topological nanoelectromechanical phononic crystal. Different strong and weak couplings are formed by changing the overlapping degree of adjacent suspended circular membranes, accompanied by different topological properties for the phononic bandgaps. Topologically protected interface states exist at their interface, and these states are stable even after introducing various degrees of distortion. Narrow band-pass filters based on these interface states can be implemented, with adjusted operating frequency by different grid voltage. Our proposed electrically tunable and integrable structure holds potential for smart filtering and may facilitate the development of integrated electromechanical circuits.