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arXiv · 2009.04963

Thermally activated flow in models of amorphous solids

Marko Popović·Tom W. J. de Geus·Wencheng Ji·Matthieu Wyart
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Abstract

Amorphous solids yield at a critical value $\Sigma_c$ of the imposed stress $\Sigma$ through a dynamical phase transition. While sharp in athermal systems, the presence of thermal fluctuations leads to the rounding of the transition and thermally activated flow even below $\Sigma_c$. Here, we study the steady state thermal flow of amorphous solids using a mesoscopic elasto-plastic model. In the Hebraud-Lequex (HL) model we provide an analytical solution of the thermally activated flow at low temperature. We then propose a general scaling law that also describes the transition rounding. Finally, we find that the scaling law holds in numerical simulations of the HL model, a 2D elasto-plastic model, and in previously published molecular dynamics simulations of 2D Lennard-Jones glass.

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Marko Popović, Tom W. J. de Geus, Wencheng Ji, Matthieu Wyart. 2020-09-10. Thermally activated flow in models of amorphous solids. https://doi.org/10.1103/physreve.104.025010

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