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

Xin Du, Eric R. Weeks
2016 Physical review. E  
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
more » ... y 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.
doi:10.1103/physreve.93.062613 pmid:27415326 fatcat:74idpsj3j5cndakbhxz6rno2ha