Nonequilibrium Glass Transition in Mixtures of Active-Passive Particles

TL;DR

This paper develops a mode coupling theory to analyze how adding active particles to passive systems affects the glass transition, revealing shifts, reentrance behavior, and different mechanisms at various activity levels.

Contribution

It introduces a theoretical framework for understanding the nonequilibrium glass transition in active-passive mixtures, highlighting non-monotonic effects of activity on glass formation.

Findings

Glass transition shifts to higher volume fractions with active doping.

Reentrant glass transition behavior depending on activity level.

Different mechanisms (caging and clustering) dominate at low and high activity.

Abstract

We develop a mode coupling theory(MCT) to study the nonequilibrium glass transition behavior of a mono-disperse mixture of active-passive hard-sphere particles. The MCT equations clearly demonstrate that the glass transition is shifted to higher values of total volume fraction when doping a passive system with active particles. Interestingly, we find that the glass transition point may show a non-monotonic dependence on the effective diffusivity of the active component, indicating a nontrivial type of activity induced reentrance behavior. Analysis based on the nonergodic parameters suggest that the glassy state at small activity is due to the caging effect, while that at high activity could result from activity induced dynamic clustering.