Ultra-wideband valley transmission on elastic topological phononic crystals

The Valley Hall effect and topological chiral boundary states play a crucial role in investigating elastic wave transmission properties. In this study, to construct the phononic crystal plate structure, periodic scatterer structures are arranged on the bottom plate at a certain thickness. Simulation analysis reveal that modulating the edge states of the designed elastic phononic crystal plate achieves greater degrees of freedom and enhanced backscattering suppression capabilities. Straight boundary, right-angle turning boundary, and valley topological transport with defect and disordered boundary are achieved by utilizing edge states. Experimental validation confirm the robustness against immunodeficiency and holes. The relative width of the topological band gap in the elastic wave system examined in this study exceeds 60%, offering significant advantages and potential for practical applications. This research contributes new insights for engineering applications of ultra-wideband acoustic antennas, acoustic logic control, and other devices.