Long-range strain correlations in 3D quiescent glass forming liquids

TL;DR

This study demonstrates that long-range strain correlations in 3D supercooled liquids and glasses decay as 1/r^3, with domain size increasing near the glass transition, supported by experiments, simulations, and theory.

Contribution

It provides the first quantitative analysis of 3D strain correlations in supercooled liquids and glasses, confirming long-range elastic-like behavior and theoretical predictions.

Findings

Strain correlations decay as 1/r^3 in 3D supercooled liquids and glasses.

The domain size of cooperative strain patterns grows near the glass transition.

Experimental and simulation results align with theoretical predictions.

Abstract

We present a quantitative study of strain correlations in quiescent supercooled liquids and glasses. Recent two-dimensional computer simulations and experiments indicate that even supercooled liquids exhibit long-lived, long-range strain correlations. Here we investigate this issue in three dimensions via experiments on hard sphere colloids and molecular dynamics simulations of a glass forming binary Lennard Jones mixture. Both in the glassy state and in the supercooled regime, strain correlations are found to decay with a $1/r^{3}$ power-law behavior, reminiscent of elastic fields around an inclusion. Moreover, theoretical predictions on the time dependence of the correlation amplitude are in line with the results obtained from experiments and simulations. It is argued that the size of the domain, which exhibits a "solid-like" cooperative strain pattern in a supercooled liquid, is determined by the product of the speed of sound with the structural relaxation time. While this length is of the order of nanometers in the normal liquid state, it grows to macroscale when approaching the glass transition.