Willis Metamaterial on a Structured Beam
LIU, Yongquan
Department of Physics [Hong Kong University of Science and Technology]
School of Physics and Astronomy [Birmingham]
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Department of Physics [Hong Kong University of Science and Technology]
School of Physics and Astronomy [Birmingham]
LIU, Yongquan
Department of Physics [Hong Kong University of Science and Technology]
School of Physics and Astronomy [Birmingham]
Department of Physics [Hong Kong University of Science and Technology]
School of Physics and Astronomy [Birmingham]
XIA, Lingbo
School of Physics and Astronomy [Birmingham]
Photonics Initiative, Advanced Science Research Center
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School of Physics and Astronomy [Birmingham]
Photonics Initiative, Advanced Science Research Center
Langue
en
Article de revue
Ce document a été publié dans
Physical Review X. 2019-02, vol. 9, n° 1, p. 1-12
American Physical Society
Résumé en anglais
Bianisotropy is common in electromagnetism whenever a cross-coupling between electric and magnetic responses exists. However, the analogous concept for elastic waves in solids, termed as Willis coupling, is more challenging ...Lire la suite >
Bianisotropy is common in electromagnetism whenever a cross-coupling between electric and magnetic responses exists. However, the analogous concept for elastic waves in solids, termed as Willis coupling, is more challenging to observe. It requires coupling between stress and velocity or momentum and strain fields, which is difficult to induce in non-negligible levels, even when using metamaterial structures. Here, we report the experimental realization of a Willis metamaterial for flexural waves. Based on a cantileverbending resonance, we demonstrate asymmetric reflection amplitudes and phases due to Willis coupling. We also show that, by introducing loss in the metamaterial, the asymmetric amplitudes can be controlled and can be used to approach an exceptional point of the non-Hermitian system, at which unidirectional zero reflection occurs. The present work extends conventional propagation theory in plates and beams to includeWillis coupling and provides new avenues to tailor flexural waves using artificial structures.< Réduire
Mots clés en anglais
Metamaterials
Acoustics
Origine
Importé de halUnités de recherche