Valley Hall elastic topological insulator with large Chern numbers

Abstract

We present a reconfigurable electro-elastic topological insulator that produces a new valley phase with a large Chern number. This piezoelectric metamaterial comprises a hexagon-like honeycomb structure and periodic bonded piezoelectric beams. The composite piezoelectric Mindlin plate formulation in the isogeometric analysis is employed to calculate the band structure. A Dirac cone can emerge at the K point due to the C3v symmetry of the primitive element. Nontrivial topologically protected bandgaps develop after breaking mirror symmetry with the adding-on negative capacitance circuit. Additionally, we demonstrate that the topological quantity in this system arises in a large valley Chern number of one. The domain wall will exhibit two edge states between different topological microstructures according to the bulk-edge correspondence principle. The shielded transport of flexural waves is highly resistant to structural disturbances such as sharp corners or cavity flaws in the proposed metamaterial, resulting in a novel strategy for the reconfigurable electro-elastic topological insulator.