Valley transport via dual-band elastic topological edge states in local-resonant phononic crystal plate

Most previously reported Dirac valley degeneracies in continuous phononic crystal plates originate from Bragg scattering of the structures and generally have only single-band elastic-wave topological edge states. In the present work, a pair of triangular prisms is used in the construction of hexagon...

Full description

Saved in:
Bibliographic Details
Published in:Journal of applied physics 2023-03, Vol.133 (9)
Main Authors: Xu, Gang-Gang, Sun, Xiao-Wei, Wen, Xiao-Dong, Liu, Xi-Xuan, Song, Ting, Liu, Zi-Jiang
Format: Article
Language:English
Subjects:
Backscattering
Crystal defects
Crystal lattices
Elastic plates
Elastic waves
Energy bands
Energy gap
Finite element method
Hall effect
Lattice vibration
Prisms
Topology
Valleys
Waveguides
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Most previously reported Dirac valley degeneracies in continuous phononic crystal plates originate from Bragg scattering of the structures and generally have only single-band elastic-wave topological edge states. In the present work, a pair of triangular prisms is used in the construction of hexagonal-lattice phononic crystal plates to mimic the dual-band elastic valley Hall effect. Based on the spatial inversion symmetry conditions, which are related to the intrinsic frequencies of the resonators, the valley degeneracies, topological nontrivial bandgaps, and energy band inversion characteristics of multiple resonance modes are investigated by using the finite element method. Edge passbands combining distinct topology phases exist in each of the two nontrivial bandgaps of the ribbon configuration. The full-field simulations for flexural waves in the waveguide structure are demonstrated to support topologically valley-protected edge transmission in both bands, which immunizes the transport against backscattering from large corners and defects in the route. This work provides a reference for valley edge protection in subwavelength continuous elastic plate media and for the manipulation of the elastic waves at multiple frequencies.
ISSN:0021-8979
1089-7550
DOI:10.1063/5.0136890