Vortex core magnetization dynamics induced by thermal excitation

We investigate the effect of temperature on the dynamic properties of magnetic vortices in small disks. Our calculations use a stochastic version of the Landau-Lifshitz-Gilbert equation valid for finite temperatures well below the Curie critical temperature. We show that a finite temperature induces a vortex precession around the center of the disk, even in the absence of other excitation sources. We discuss the origin and implications of the appearance of such dynamics. We also show that a temperature gradient plays a role similar to that of a small constant magnetic field.