Intrinsic anomalous scaling in a ferromagnetic thin film model

Abstract

Recently, the interest on theoretical and experimental studies of dynamic properties of the magnetic domain wall (MDW) of ferromagnetic thin films with disorder placed in an external magnetic field has increased. In order to study global and local measurable observables, we consider the (1 + 1)-dimensional model introduced by Buceta and Muraca [Physica A 390, 4192 (2011)], based on rules of evolution that describe the MDW avalanches. From the values of the roughness exponents, global ζ, local Cioc, and spectral ζs, obtained from the global interface width, height-difference correlation function and structure function, respectively, recent works have concluded that the universality classes should be analyzed in the context of the anomalous scaling theory. We show that the model is included in the group of systems with intrinsic anomalous scaling (ζ ~ 1.5, ζioc = Cs — 0.5), and that the surface of the MDW is multi-affine. With these results, we hope to establish in short term the scaling relations that verify the critical exponents of the model, including the dynamic exponent z, the exponents of the distributions of avalanche-size τ and -duration 𝛼, among others.