Tuning of Higher-Order Topological Corner States in a Honeycomb Elastic Plate

Abstract

Different from the traditional bulk-edge correspondence principle, the discovery of higher-order topological states has generated widespread interest. In a second-order, two-dimensional elastic wave topological insulator, the fluctuation information can be confined to the corners, with the state being topologically protected. To better apply the topological corner states, a cleverly designed mechanical structure is used to achieve the adjustment of the topological corner states on a two-dimensional elastic plate. The energy-band inversion can be achieved by switching the material of the inner and outer brackets of the unit cell of the honeycomb elastic plate. The topological corner states can be observed at the boundary of two different topological phase structures in the finite lattice using finite-element software. The robustness of the topological corner state is verified by setting up defective control groups at the corner. In addition, the topological corner states of this honeycomb elastic plate are discussed in terms of positional tunability. The honeycomb elastic plate can provide a reference for the design of devices for the local control of elastic waves and energy harvesting due to the possibility of modulation of topological corner states, which is beneficial for the application of topological corner states in practice.