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Dirac cones and chiral selection of elastic waves in a soft strip.

ABSTRACT: We study the propagation of in-plane elastic waves in a soft thin strip, a specific geometrical and mechanical hybrid framework which we expect to exhibit a Dirac-like cone. We separate the low frequencies guided modes (typically 100 Hz for a 1-cm-wide strip) and obtain experimentally the full dispersion diagram. Dirac cones are evidenced together with other remarkable wave phenomena such as negative wave velocity or pseudo-zero group velocity (ZGV). Our measurements are convincingly supported by a model (and numerical simulation) for both Neumann and Dirichlet boundary conditions. Finally, we perform one-way chiral selection by carefully setting the source position and polarization. Therefore, we show that soft materials support atypical wave-based phenomena, which is all of the more interesting as they make most of the biological tissues.

SUBMITTER: Lanoy M

PROVIDER: S-EPMC7720205 | biostudies-literature | 2020 Dec

REPOSITORIES: biostudies-literature

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Dirac cones and chiral selection of elastic waves in a soft strip.

Lanoy Maxime M Lemoult Fabrice F Eddi Antonin A Prada Claire C

Proceedings of the National Academy of Sciences of the United States of America 20201118 48

We study the propagation of in-plane elastic waves in a soft thin strip, a specific geometrical and mechanical hybrid framework which we expect to exhibit a Dirac-like cone. We separate the low frequencies guided modes (typically 100 Hz for a 1-cm-wide strip) and obtain experimentally the full dispersion diagram. Dirac cones are evidenced together with other remarkable wave phenomena such as negative wave velocity or pseudo-zero group velocity (ZGV). Our measurements are convincingly supported b ...[more]

PMID: 33208536

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