Search for universal roughness distributions in a critical interface model

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^α noise. Periodic, free, “window,” and mixed boundary conditions are examined, with rather distinct results as regards quality of fits to 1∕f^α distributions.