Dynamic criticality in driven disordered systems: Role of depinning and driving rate in Barkhausen noise

TL;DR

This paper investigates Barkhausen noise in a 2D Ising model, revealing how disorder and driving rate influence scaling behavior and critical dynamics in driven disordered systems.

Contribution

It introduces a detailed analysis of Barkhausen noise scaling in different disorder regimes and links low-disorder behavior to a universal critical dynamic class.

Findings

Two distinct scaling regimes identified: low and high disorder.

Universal scaling at low disorder linked to a fixed point of a stochastic transport equation.

Effects of nonmagnetic ion concentration and driving rate on scaling exponents analyzed.

Abstract

We study Barkhausen noise in a diluted two-dimensional Ising model with the extended domain wall and weak random fields occurring due to coarse graining. We report two types of scaling behavior corresponding to (a) low disorder regime where a single domain wall slips through a series of positions when the external field is increased, and (b) large disorder regime, which is characterized with nucleation of many domains. The effects of finite concentration of nonmagnetic ions and variable driving rate on the scaling exponents is discussed in both regimes. The universal scaling behavior at low disorder is shown to belong to a class of critical dynamic systems, which are described by a fixed point of the stochastic transport equation with self-consistent disorder correlations.