How to Study a Persistent Active Glassy System?

TL;DR

This paper introduces a new simulation scheme for studying the long-time dynamics of dense active glasses with large persistence times, enabling detailed analysis of plastic events.

Contribution

The paper presents an activity-driven dynamics scheme that accurately captures the behavior of active glasses in the large persistence time limit, overcoming previous computational challenges.

Findings

The scheme reproduces all relevant dynamical quantities as tau_p approaches infinity.

It enables detailed statistical analysis of Eshelby-like plastic events.

The approach is validated through comparison with established dynamics.

Abstract

We explore glassy dynamics of dense assemblies of soft particles that are self-propelled by active forces. These forces have a fixed amplitude and a propulsion direction that varies on a timescale tau_p, the persistence timescale. Numerical simulations of such active glasses are computationally challenging when the dynamics is governed by large persistence times. We describe in detail a recently proposed scheme that allows one to study directly the dynamics in the large persistence time limit, on timecales around and well above the persistence time. We discuss the idea behind the proposed scheme, which we call activity-driven dynamics, as well as its numerical implementation. We establish that our prescription faithfully reproduces all dynamical quantities in the appropriate limit tau_p goes to infinity. We deploy the approach to explore in detail the statistics of Eshelby-like plastic events in the steady state dynamics of a dense and intermittent active glass.