Decorrelation of the static and dynamic length scales in hard-sphere glass-formers

TL;DR

This study demonstrates that in three-dimensional hard-sphere glass-formers, static and dynamic length scales decouple as density increases, indicating multiple relaxation mechanisms without a direct link to relaxation time.

Contribution

It provides the first clear evidence of decorrelation between static and dynamic length scales in hard-sphere glasses within accessible simulation ranges.

Findings

Static length scales grow slower than dynamic ones with increasing density.

No direct correlation between relaxation time and point-to-set length.

Multiple relaxation mechanisms coexist in the studied regime.

Abstract

We show that in the equilibrium phase of glass-forming hard-sphere fluids in three dimensions, the static length scales tentatively associated with the dynamical slowdown and the dynamical length characterizing spatial heterogeneities in the dynamics unambiguously decorrelate. The former grow at a much slower rate than the latter when density increases. This observation is valid for the dynamical range that is accessible to computer simulations, which roughly corresponds to that of colloidal experiments. We also find that in this same range, no one-to-one correspondence between relaxation time and point-to-set correlation length exists. These results point to the coexistence of several relaxation mechanisms in the accessible dynamical regime of three-dimensional hard-sphere glass formers.