Titre :

Polarization-dependent and Valley-protected Lamb Waves in Asymmetric Pillared Phononic Crystals

Auteur(s) :

Wang, Wei [Auteur]
Sorbonne Université [SU]
Bonello, Bernard [Auteur]
Acoustique pour les nanosciences [INSP-E3]
Djafari-Rouhani, Bahram [Auteur]
Physique - IEMN [PHYSIQUE - IEMN]
Institut d’Électronique, de Microélectronique et de Nanotechnologie - UMR 8520 [IEMN]
Pennec, Yan [Auteur]
Physique - IEMN [PHYSIQUE - IEMN]
Institut d’Électronique, de Microélectronique et de Nanotechnologie - UMR 8520 [IEMN]

Titre de la revue :

Journal of Physics D: Applied Physics

Pagination :

505302

Éditeur :

IOP Publishing

Date de publication :

2019

ISSN :

0022-3727

Discipline(s) HAL :

Physique [physics]

Résumé en anglais : [en]

We present the realization of the topological valley-protected zero-order antisymmetric (A 0) or symmetric (S 0) and zero-order shear-horizontal (SH 0) Lamb waves at different domain walls based on topologically distinct ...
Lire la suite >We present the realization of the topological valley-protected zero-order antisymmetric (A 0) or symmetric (S 0) and zero-order shear-horizontal (SH 0) Lamb waves at different domain walls based on topologically distinct asymmetric double-sided pillared phononic crystals. The elastic periodic structures have either the triangular or the honeycomb symmetry and give rise to a double-negative branch in the dispersion curves. By artificially folding the doubly negative branch, a degenerate Dirac cone is achieved. Different polarization-dependent propagation along the same primary direction along the constituent branches are presented. Moreover, divergent polarization-dependent phenomena along different primary directions along a given branch are also reported. By imposing two large space-inversion symmetry (SIS) breaking perturbations the topological phase transition is obtained. We show that the Berry curvature becomes strongly anisotropic when the wave vector gets away from the valleys. Further, we demonstrate the unidirectional transport of A 0 , S 0 , and SH 0 Lamb waves at different domain walls in straight or Z-shape wave guides. In the large SIS breaking case, we show negligible reflection at the zigzag outlet of the straight wave guide and occurrence of weak inter-valley scattering at the bending corners of the Z-shape wave guide. For a larger strength of SIS breaking, the edge states are gapped and strong reflection at the zigzag outlet and bending corners is observed. The topological protection cannot be guaranteed any more in that case.Lire moins >

Langue :

Anglais

Vulgarisation :

Non

Collections :

• Institut d'Électronique, de Microélectronique et de Nanotechnologie (IEMN) - UMR 8520

Source :

Harvested from HAL