Local Plastic Response and Slow Heterogeneous Dynamics of Supercooled Liquids

TL;DR

This paper uses numerical simulations to link the relaxation dynamics of supercooled liquids to a plastic length scale that measures particle response to localized perturbations, revealing its temperature dependence and relation to particle displacements.

Contribution

It introduces a plastic length scale as a key factor controlling supercooled liquid dynamics and demonstrates its correlation with relaxation times and particle displacements.

Findings

Plastic length scale vanishes linearly with temperature.

Plastic length scale controls super-Arrhenius relaxation behavior.

Plastic length scale correlates with particle displacements at relaxation time.

Abstract

We demonstrate, via numerical simulations, that the relaxation dynamics of supercooled liquids correlates well with a plastic length scale measuring a particle's response to impulsive localized perturbations and weakly to measures of local elasticity. We find that the particle averaged plastic length scale vanishes linearly in temperature and controls the super-Arrhenius temperature dependence of the relaxation time. Furthermore, we show that the plastic length scale of individual particles correlates with their typical displacement at the relaxation time. In contrast, the local elastic response only correlates with the dynamics on the vibrational time scale.