Relaxation dynamics in magnetic skyrmions with quenched disorder*

Magnetic skyrmions are topologically protected spin textures of nanometer size found in certain chiral magnets. Skyrmions can be moved by very low current densities which makes them ideal for applications in spintronics such as data storage devices and logic gates. A thorough understanding of the relaxation processes for systems of interacting skyrmions far from equilibrium could prove invaluable in real world applications. We use a particle based model derived from Thiele's approach to study the relaxation dynamics of two-dimensional skyrmions subject to quenched disorder and a time-dependent Gaussian noise. The particle model differs most notably from similar models which describe vortices in type-II superconductors by the addition of the Magnus force which always acts perpendicular to the forces in the plane. Previously, it was shown that the interplay between the Magnus force, repulsive skyrmion-skyrmion interaction and Gaussian noise yields different regimes during non-equilibrium relaxation. In this work, we focus on the effects of randomly distributed attractive defects on the relaxation process.