Time evolution of dynamic propensity in a model glass former. The interplay between structure and dynamics

TL;DR

This study investigates how the spatial distribution of particle mobility in a glass-forming system evolves over time, revealing that significant changes occur during collective relaxation events called d-clusters, which de-correlate local structural influences.

Contribution

It demonstrates the link between relaxation events (d-clusters) and changes in the dynamic propensity distribution in a model glass former.

Findings

Spatial propensity distribution remains stable until d-clusters occur.

D-clusters cause a significant de-correlation of particle propensity.

Particles involved in d-clusters show high changes in their propensity.

Abstract

By means of the isoconfigurational method we calculate the change in the propensity for motion that the structure of a glass-forming system experiences during its relaxation dynamics. The relaxation of such a system has been demonstrated to evolve by means of rapid crossings between metabasins of its potential energy surface (a metabasin being a group of mutually similar, closely related structures which differ markedly from other metabasins), as collectively relaxing units (d-clusters) take place. We now show that the spatial distribution of propensity in the system does not change significantly until one of these d-clusters takes place. However, the occurrence of a d-cluster clearly de-correlates the propensity of the particles, thus ending up with the dynamical influence of the structural features proper of the local metabasin. We also show an important match between particles that participate in d-clusters and that which show high changes in their propensity.