De-coupling of Exchange and Persistence Times in Atomistic Models of Glass Formers

TL;DR

This study uses molecular dynamics simulations to analyze local persistence and exchange times in glass-forming liquids, revealing de-coupling phenomena similar to lattice models, thus enhancing understanding of glassy dynamics.

Contribution

It demonstrates the de-coupling of exchange and persistence times in atomistic models, bridging the gap between lattice models and real glass-forming liquids.

Findings

De-coupling of exchange and persistence times observed.

Behavior consistent with kinetically constrained lattice models.

Implications for understanding glassy dynamics in real materials.

Abstract

With molecular dynamics simulations of a fluid mixture of classical particles interacting with pair-wise additive Weeks-Chandler-Andersen potentials, we consider the time series of particle displacements and thereby determine distributions for local persistence times and local exchange times. These basic characterizations of glassy dynamics are studied over a range of super-cooled conditions and shown to have behaviors, most notably de-coupling, similar to those found in kinetically constrained lattice models of structural glasses. Implications are noted.