Thermal vestiges of avalanches in the driven random field Ising model

TL;DR

This study explores how avalanche phenomena in the 3D random field Ising model persist at finite temperatures, revealing differences from zero-temperature behavior and the influence of thermal activation.

Contribution

It provides the first detailed numerical analysis of avalanche behavior at finite temperature in the RFIM, highlighting thermal effects and scaling properties.

Findings

Avalanches persist over a range of finite temperatures.

Thermal avalanches show an excess of small events.

Activated dynamical scaling describes thermal avalanche behavior.

Abstract

We investigate the non-equilibrium behavior of the $3d$ random field Ising model at finite temperature, as an external field is increased through its coercive field. We show by numerical simulations that the phenomenology of avalanches -- which are sharply defined only at zero temperature -- also persists over a significant range of finite temperatures. We analyse the main differences between the thermal and zero-temperature systems, including an excess of small avalanches in the thermal case, whose behaviour is consistent with activated dynamical scaling. We also investigate the extent to which individual avalanches at finite temperature can be traced back to parent avalanches in the athermal system.