Dynamic Rearrangements of a Three-Dimensional Topological Structure of a Moving Domain Wall in Magnetic Film in the Presence of Random Perturbations

Abstract

Using three-dimensional micromagnetic simulation, the dynamic processes occurring in a domain wall (DW) that moves under the influence of a constant magnetic field in a magnetically soft uniaxial film with planar anisotropy are studied. It is shown that the general picture of the dynamics of topological transformations taking place in DWs can significantly vary with the introduction of perturbing factors that randomly depend on the coordinates or time (spatially heterogeneous anisotropy; a magnetic field fluctuating in time). Moreover, the characteristic configurations of a vector magnetization field near the intrafilm vortex cores and singular (Bloch) points preserve their shape. The dependences of the energy and DW shifts on the time are determined for a wide range of film thickness values, temperatures, and magnetic field intensities. Imaging techniques based on calculating two types of topological charges are used when analyzing magnetization configurations.