title: Energy barriers, entropy barriers, and non-Arrhenius behavior in a minimal glassy model.
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 that 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.
authors.affiliation: Department of Physics, Emory University, Atlanta, Georgia 30322, USA.
authors.forename: Xin
authors.initials: X
authors.lastname: Du
authors.affiliation: Department of Physics, Emory University, Atlanta, Georgia 30322, USA.
authors.forename: Eric R
authors.initials: ER
authors.lastname: Weeks