Dynamics of magnetic vortices in the field of local inhomogeneity of a ferromagnet

Abstract

The rotation of a magnetic vortex in a ferromagnet with a local smooth change in the exchange interaction is considered. The frequency of this precession is found for all distances of the vortex from defect center. The rotation velocity of the vortex nonmonotonically depends on the distance to the center, reaching a maximum at a distance of the order of the characteristic dimension of the defect. The decrease in velocity at large distances agrees with the data known in the literature. Accounting of attenuation leads to the vortex escape the defect or falling onto it along a logarithmic spiral.