Revealing topological attributes of stiff plates by Dirac factorization of their 2D elastic wave equation
Revealing topological attributes of stiff plates by Dirac factorization of their 2D elastic wave equation
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DOI：
10.1063/5.0086559
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发表时间：
2022-02
影响因子：
4
通讯作者：
P. Deymier;K. Runge
中科院分区：
文献类型：
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作者：
P. Deymier;K. Runge
耦合到刚性基底的二维刚性板的弹性波方程的狄拉克分解揭示了该系统中弹性波可能的拓扑特性。这些波可能具有与带隙结构相关的类自旋自由度，让人想起自旋霍尔效应。在具有零位移边缘的半无限板或带中，狄拉克因子弹性波方程显示了边缘模式沿相反方向移动的可能性。条带的有限尺寸导致边缘模式之间重叠，从而在其光谱中打开一个间隙，从而消除了类自旋霍尔效应。狄拉克分解告诉我们，如果我们能够打破某些对称性，弹性波方程的解将会是什么。狄拉克分解不会破坏对称性，而只是揭示了对称性破坏结构或外部扰动可能导致弹性波的拓扑性质。
Dirac factorization of the elastic wave equation of two-dimension stiff plates coupled to a rigid substrate reveals the possible topological properties of elastic waves in this system. These waves may possess spin-like degrees of freedom associated with a gapped band structure reminiscent of the spin Hall effect. In semi-infinite plates or strips with zero displacement edges, the Dirac-factored elastic wave equation shows the possibility of edge modes moving in opposite directions. The finite size of strips leads to overlap between edge modes consequently opening a gap in their spectrum eliminating the spin Hall-like effects. This Dirac factorization tells us what solutions of the elastic wave equation would be if we could break some symmetry. Dirac factorization does not break symmetry but simply exposes what topological properties of elastic waves may result from symmetry breaking structural or external perturbations.