Avalanches in active glasses with finite persistence

TL;DR

This study explores how activity and external shear influence avalanche behavior in active glasses, revealing conditions for power-law stress drops and universal avalanche structures across different activity regimes.

Contribution

It uncovers the interplay between activity persistence and shear in avalanche statistics, extending understanding beyond the infinite-persistence limit.

Findings

Power-law stress drops occur with sufficient activity correlations.

Avalanche structure and scaling are universal across activity regimes.

Activity increases the size of regions involved in avalanches.

Abstract

We numerically investigate the statistics of avalanches in glassy systems of active particles with finite persistence, with and without an externally applied shear. In departing from the infinite-persistence limit and exploring the interplay of internal activity and external driving, we uncover when and why active and passive systems display similar avalanche statistics and where these analogies fail. We find that power-law distributed stress drops emerge only when activity builds long enough correlations, controlled by the persistence length, with exponents that vary from the purely strain-driven case, to the purely activity-driven case, in a smooth fashion. The local structure and scaling of avalanches of plastic rearrangements remains universal across both limit cases, supporting an interpretation of activity as increasing the typical size of the regions involved in a given avalanche. Our results bridge quasistatic shear strain and finite-persistence active yielding, showing that avalanches driven by self-propulsion retain the characteristic fingerprints of long-range stress propagation.