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arXiv · 2405.01878

Aubry transition with small distortions

O. Cépas·P. Quémerais
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Abstract

We show that when the Aubry transition occurs in incommensurately distorted structures, the amplitude of the distortions is not necessarily large as suggested by the standard Frenkel-Kontorova mechanical model. By modifying the shape of the potential in such a way that the mechanical force is locally stronger (i.e. increasing the nonlinearities), the transition may occur at a small amplitude of the potential with small distortions. A "phason" gap then opens, while the phonon spectrum resembles a standard undistorted spectrum at higher energies. This may explain the existence of pinned phases with small distortions as experimentally observed in charge-density waves.

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O. Cépas, P. Quémerais. 2024-05-03. Aubry transition with small distortions. https://doi.org/10.1103/physreve.110.044206

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