基于手性声子晶体的谷拓扑声输运

Valley topological acoustic transport based on chiral sonic crystals

研究手性风车形散射体构建的谷拓扑声波导。具有右手与左手手性风车形散射体的声子晶体具有截然不同的声谷拓扑特性。当两种手性风车形散射体从-60°旋转到60°时,其所构建的声子晶体均出现2次偶然简并的狄拉克点与谷霍尔相变。基于两种具有相反谷霍尔相的手性声子晶体构建的谷拓扑声波导,在其重叠体带隙内存在一对局域在波导分界面处的谷态边缘态。实验研究表明,该边缘态可以很好的支持谷拓扑声输运,且对弯曲与无序两种缺陷具有一定的鲁棒性.

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.