Confirmation of Anomalous Dynamical Arrest in attractive colloids: a molecular dynamics study

TL;DR

This study uses molecular dynamics simulations to confirm complex dynamical arrest phenomena in attractive colloids, including reentrance, logarithmic singularities, and coexistence of glasses, providing direct evidence for these theoretical predictions.

Contribution

The paper provides the first direct simulation evidence of the coexistence of attractive and repulsive glasses in dense colloidal systems.

Findings

Confirmed re-entrance in dynamical arrest curve

Observed logarithmic singularity in density correlation functions

Provided direct evidence of coexisting glasses

Abstract

Previous theoretical, along with early simulation and experimental, studies have indicated that particles with a short-ranged attraction exhibit a range of new dynamical arrest phenomena. These include very pronounced reentrance in the dynamical arrest curve, a logarithmic singularity in the density correlation functions, and the existence of `attractive' and `repulsive' glasses. Here we carry out extensive molecular dynamics calculations on dense systems interacting via a square-well potential. This is one of the simplest systems with the required properties, and may be regarded as canonical for interpreting the phase diagram, and now also the dynamical arrest. We confirm the theoretical predictions for re-entrance, logarithmic singularity, and give the first direct evidence of the coexistence, independent of theory, of the two coexisting glasses. We now regard the previous predictions of these phenomena as having been established.