Charge avalanches and depinning in the Coulomb glass: The role of long-range interactions

TL;DR

This study investigates how long-range Coulomb interactions influence the nonequilibrium charge dynamics and depinning transition in a three-dimensional Coulomb glass, revealing a critical electric field where scale-free avalanches occur.

Contribution

It demonstrates the crucial role of long-range interactions in the depinning transition and charge avalanches, contrasting with short-range models.

Findings

Sharp depinning transition at a critical electric field

Scale-free avalanches only at the critical point

Long-range interactions fundamentally alter nonequilibrium dynamics

Abstract

We explore the stability of far-from-equilibrium metastable states of a three-dimensional Coulomb glass at zero temperature by studying charge avalanches triggered by a slowly varying external electric field. Surprisingly, we identify a sharply defined dynamical ("depinning") phase transition from stationary to nonstationary charge displacement at a critical value of the external electric field. Using particle-conserving dynamics, scale-free system-spanning avalanches are observed only at the critical field. We show that the qualitative features of this depinning transition are completely different for an equivalent short-range model, highlighting the key importance of long-range interactions for nonequilibrium dynamics of Coulomb glasses.