No abstract

When spin polarised electrons flow through a magnetic texture a transfer torque is generated. We examine the effect of this torque on skyrmions and skyrmion bags, skyrmionic structures of arbitrary integer topological degree, in thin ferromagnetic films. Using micromagnetic simulations and analysis from the well known Thiele equation we explore the potential for sorting or binning skyrmions of varying degrees mechanically. We investigate the applicability of the Thiele equation to problems of this nature and derive a theory of skyrmion deflection ordered by topological degree. We show that skyrmions and skyrmion bags have the potential to move in different directions under constant current which has significant potential for technical applications.

Skyrmion bags are spin textures of any integer topological degree, realized in micromagnetic simulations and experimentally in liquid crystals. They have been proposed as a promising new form of magnetic data storage due to their stability with respect to perturbations and the possibility of encoding different values in topologically distinct magnetization configurations. We simulate skyrmion bags in magnetic thin films having a range of physically realistic material parameters. The results give a range over which stable skyrmion bags may be found in experiment, and we extract a relationship to help guide the production of these potentially useful quasiparticles.