Finite-Frequency Topological Maxwell Modes in Mechanical Self-Dual Kagome Lattices
Finite-Frequency Topological Maxwell Modes in Mechanical Self-Dual Kagome Lattices
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DOI：
10.1103/physrevlett.129.204302
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发表时间：
2022-11-10
影响因子：
8.6
通讯作者：
Tol, Serife
中科院分区：
文献类型：
--
作者：
Danawe, Hrishikesh;Li, Heqiu;Tol, Serife
本文研究了一种具有临界扭角的弹性扭曲kagome晶格，即自对偶kagome晶格，在满足一定条件时呈现出特殊的有限频率拓扑模式。这些态在拓扑上与麦克斯韦晶格的零能量（软盘）模式相似，但它们以有限频率出现在自对偶kagome晶格的带隙中。因此，我们提出了一类全新的拓扑模式，它们与麦克斯韦晶格中的零频率软盘模式和拓扑绝缘体中的有限能量隙内模式有相似之处。我们设想所提出的数学和数值框架对于许多与波现象有关的技术进步是无价的，例如可重构波导设计。
In this Letter, an elastic twisted kagome lattice at a critical twist angle, called self-dual kagome lattice, is shown to exhibit peculiar finite-frequency topological modes which emerge when certain conditions are satisfied. These states are topologically reminiscent of the zero energy (floppy) modes of Maxwell lattices, but they occur at a finite frequency in the band gap of the self-dual kagome lattice. Thus, we present a completely new class of topological modes that share similarities with both the zero frequency floppy modes in Maxwell lattices and the finite energy in-gap modes in topological insulators. We envision the presented mathematical and numerical framework to be invaluable for many technological advances pertaining to wave phenomena, such as reconfigurable waveguide designs.