Interactions between a magnetic skyrmion and anisotropy walls

摘要

The magnetic skyrmion is a topologically protected spin texture. We have previously reported thesimulation results for the motion of skyrmions in magnetic nanowires patterned by the magnetic anisotropyundulation . Our study was focused on the forces induced by the anisotropy gradient and the anisotropywalls. In this study, we simulate the motion of skyrmions interacting with the anisotropy walls more precisely,and give an analytical explanation to the obtained results.The micromagnetic simulator MuMax_3 has been used for calculating the skyrmion motion in the nanowirewith the anisotropy gradient. The force by anisotropy gradient is determined in terms of skyrmion’s velocity.In Fig. 1, we show schematically the gradient force Fg and the (Magnus) gyrocoupling force G×v . Therepulsive forces from the walls are in balance with these 2 forces. We have found that the reactions from thewall for both Fg and G×v depend only on the distance from the wall X besides the skyrmion’s radius andshape and the functions are identical. It can be described in terms of a potential.