Valley topological acoustic transport based on chiral sonic crystals

A valley topological acoustic waveguide based on chiral windmill scatterers is studied.The sonic crystals composed of right-handed and left-handed chiral scatterers have different valley topology property.When the two kinds of chiral windmill scatterers rotate from-60°to 60°,the corresponding sonic crystals both exhibit two accidental degenerated Dirac points and valley Hall phase transition.Two chiral sonic crystals with opposite valley Hall phase are selected to construct an acoustic waveguide.We find that there exist a pair of valley edge states localized at the interface of the waveguide in the overlapping band gap.The experimental results show that the edge states can support valley topological acoustic transport well.Moreover,it has a certain robustness to the defects of bending and disorder in the waveguide.