Solid-like mean-square displacement in glass-forming liquids

Thomas B. Schrøder; Jeppe C. Dyre

doi:10.1063/5.0004093

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arXiv · 1905.11514

Solid-like mean-square displacement in glass-forming liquids

Thomas B. Schrøder·Jeppe C. Dyre

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Abstract

It was recently shown that the real part of the frequency-dependent fluidity for several glass-forming liquids of different chemistry conforms to the prediction of the random barrier model (RBM) devised for ac electrical conduction in disordered solids [S. P. Bierwirth \textit{et al.}, Phys. Rev. Lett. {\bf 119}, 248001 (2017)]. Inspired by these results we introduce a crystallization-resistant modification of the Kob-Andersen binary Lennard-Jones mixture for which the results of extensive graphics-processing unit (GPU)-based molecular-dynamics simulations are presented. We find that the low-temperature mean-square displacement is fitted well by the RBM prediction, which involves no shape parameters. This finding highlights the challenge of explaining why a simple model based on hopping of non-interacting particles in a fixed random energy landscape can reproduce the complex and highly cooperative dynamics of glass-forming liquids.

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Thomas B. Schrøder, Jeppe C. Dyre. 2020-03-07. Solid-like mean-square displacement in glass-forming liquids. https://doi.org/10.1063/5.0004093

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