Universality classes and crossover scaling of Barkhausen noise in thin films

TL;DR

This paper investigates the critical behavior of Barkhausen noise in ferromagnetic thin films, revealing a crossover between two roughness regimes with distinct scaling laws, supported by experimental data.

Contribution

It identifies and characterizes a crossover in domain wall morphology and avalanche dynamics in thin films, linking theoretical predictions with experimental observations.

Findings

Two distinct roughness regimes with different critical exponents

Quantitative agreement with experimental measurements on MnAs thin films

Crossover driven by competition between surface tension and dipolar interactions

Abstract

We study the dynamics of head-to-head domain walls separating in-plane domains in a disordered ferromagnetic thin film. The competition between the domain wall surface tension and dipolar interactions induces a crossover between a rough domain wall phase at short length-scales and a large-scale phase where the walls display a zigzag morphology. The two phases are characterized by different critical exponents for Barkhausen avalanche dynamics that are in quantitative agreement with experimental measurements on MnAs thin films.