二维蜂窝弹性材料拓扑态的研究

将谷拓扑态的概念引入弹性材料,设计了一种二维蜂窝弹性声子晶体,当系统受反演对称性保护时,在K(K′)点处出现3个线性简并的狄拉克点,分布在不同的频段.通过调整其几何结构参数,破坏体系的空间对称性,使得在K(K′)点处的狄拉克点打开,形成能谷.这种多频段的能谷之间存在连接上、下体带的边缘态,在弹性材料中利用边缘态实现拓扑输运,可以设计出有良好性能的声学器件,具有一定的研究价值.

Topological States of Two-Dimensional Honeycomb Elastic Materials

We introduce the concept of valley states to elastic materials and design a two-dimensional honeycomb elastic phonon crystal.When the system is protected by inverse symmetry,three pairs of Dirac points appear at the K and K′ point,distributed in different frequency bands.The spatial symmetry of the system is broken by adjusting its geometrical structure parameters so that the Dirac points open and form valley at the K and K′ point.In this multi-band valley exists edge states connecting the upper and lower body bands,which is used in elastic materials can be used to achieve edge transport and design acoustic devices with good performance.