Motile topological defects hinder dynamical arrest in dense liquids of active ellipsoids

TL;DR

This study investigates how motile topological defects in dense active ellipsoid liquids influence their glassy dynamics, revealing that high activity levels cause intermittent jamming and unjamming behaviors.

Contribution

It uncovers the role of motile topological defects in active ellipsoid liquids and their impact on dynamical arrest at high densities.

Findings

Motile topological defects hinder dynamical arrest in dense active liquids.

High activity induces intermittent jamming and unjamming of defects.

Reentrant dynamics observed in both translational and orientational degrees of freedom.

Abstract

Recent numerical studies have identified the persistence time of active motion as a critical parameter governing glassy dynamics in dense active matter. Here we studied dynamics in liquids of granular active ellipsoids with tunable persistence and velocity. We show that increasing the persistence time at moderate supercooling is equivalent to increasing the strength of attraction in equilibrium liquids and results in reentrant dynamics not just in the translational degrees of freedom, as anticipated, but also in the orientational ones. However, at high densities, motile topological defects, unique to active liquids of elongated particles, hindered dynamical arrest. Most remarkably, for the highest activity, we observed intermittent dynamics due to the jamming-unjamming of these defects for the first time.