Can the dynamics of an atomic glass-forming system be described as a continuous time random walk?

TL;DR

This paper demonstrates that the complex dynamics of supercooled liquids can be effectively modeled as a continuous time random walk by mapping transitions between metabasins, providing a new framework for understanding glassy dynamics.

Contribution

It introduces a novel approach of describing atomic glass-forming system dynamics using CTRW based on metabasins, validated through quantitative tests.

Findings

Wave vector dependence of relaxation time explained by CTRW

Degree of non-exponentiality characterized by waiting time moments

Validation of CTRW conditions for supercooled liquids

Abstract

We show that the dynamics of supercooled liquids, analyzed from computer simulations of the binary mixture Lennard-Jones system, can be described in terms of a continuous time random walk (CTRW). The required discretization comes from mapping the dynamics on transitions between metabasins. This comparison involves verifying the conditions of the CTRW as well as a quantitative test of the predictions. In particular it is possible to express the wave vector-dependence of the relaxation time as well as the degree of non-exponentiality in terms of the first three moments of the waiting time distribution.