Signatures of Dynamical Heterogeneity in the Structure of Glassy Free-energy Minima

TL;DR

This paper demonstrates that the spatial variation in local density peaks at glassy free-energy minima correlates with dynamical heterogeneity observed in simulations, linking structural features to dynamic behavior in glasses.

Contribution

It reveals a direct connection between the structure of glassy free-energy minima and dynamical heterogeneity through numerical and simulation analysis.

Findings

Large spatial variation in local density peaks at minima

Correlation between structural heterogeneity and dynamical heterogeneity

Validation through molecular dynamics simulations

Abstract

From numerical minimization of a model free energy functional for a system of hard spheres, we show that the width of the local peaks of the time-averaged density field at a glassy free-energy minimum exhibits large spatial variation, similar to that of the ``local Debye-Waller factor'' in simulations of dynamical heterogeneity. Molecular dynamics simulations starting from a particle configuration generated from the density distribution at a glassy free-energy minimum show similar spatial heterogeneity in the degree of localization, implying a direct connection between dynamical heterogeneity and the structure of glassy free energy minima.