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arXiv · 1511.09453

Energy barriers, entropy barriers, and non-Arrhenius behavior in a minimal glassy model

Xin Du·Eric R. Weeks
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Abstract

We study glassy dynamics using a simulation of three soft Brownian particles confined to a two-dimensional circular region. If the circular region is large, the disks freely rearrange, but rearrangements are rarer for smaller system sizes. We directly measure a one-dimensional free energy landscape characterizing the dynamics. This landscape has two local minima corresponding to the two distinct disk configurations, separated by a free energy barrier which governs the rearrangement rate. We study several different interaction potentials and demonstrate that the free energy barrier is composed of a potential energy barrier and an entropic barrier. The heights of both of these barriers depend on temperature and system size, demonstrating how non-Arrhenius behavior can arise close to the glass transition.

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Xin Du, Eric R. Weeks. 2016-04-21. Energy barriers, entropy barriers, and non-Arrhenius behavior in a minimal glassy model. https://doi.org/10.1103/physreve.93.062613

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