Search for universal roughness distributions in a critical interface model

TL;DR

This study analyzes interface roughness distributions in a model for Barkhausen noise, showing it belongs to the Edwards-Wilkinson universality class and exploring boundary condition effects on roughness distributions.

Contribution

It demonstrates the irrelevance of a demagnetization mechanism and investigates the fit of roughness data to 1/f^α noise distributions across various boundary conditions.

Findings

Model belongs to Edwards-Wilkinson universality class.

Demagnetization mechanism is irrelevant for universality.

Boundary conditions significantly affect roughness distribution fits.

Abstract

We study the probability distributions of interface roughness, sampled among successive equilibrium configurations of a single-interface model used for the description of Barkhausen noise in disordered magnets, in space dimensionalities $d=2$ and 3. The influence of a self-regulating (demagnetization) mechanism is investigated, and evidence is given to show that it is irrelevant, which implies that the model belongs to the Edwards-Wilkinson universality class. We attempt to fit our data to the class of roughness distributions associated to $1/f^\alpha$ noise. Periodic, free, ``window'', and mixed boundary conditions are examined, with rather distinct results as regards quality of fits to $1/f^\alpha$ distributions.