Double-banded Topology Valley Transport

The advent of topology theory has facilitated the emergence of unique physical properties in engineered structures, garnering significant interest and investigation. This paper presents a phonon crystal design approach predicated on the Valley Hall effect, capable of achieving energy band inversion and topological valley transport across various frequency ranges. By merely rotating the scatterer, multiple coexisting linear Dirac points at the Brillouin zone K point can be disrupted, giving rise to bandgaps exhibiting distinct topological characteristics. Reversing the rotation direction simultaneously alters the vortex chirality. This inherent property lays the foundation for topological valley transport. Furthermore, this paper examines the two-band valley transport attributes of phonon crystals with diverse transmission routes. To explore the applicability of the designed phonon crystal in topological acoustics, a two-band acoustic splitter is employed to investigate topological transport behavior. Simulation outcomes demonstrate exceptional transport performance. This study offers novel insights for sound wave control design and bears potential applicability to multifunctional acoustic devices such as acoustic sensors, acoustic signal processing, and acoustic communication.