Current-driven and field-driven domain walls at nonzero temperature

We present a model for the dynamics of current-driven and field-driven domain-wall lines at nonzero temperature. We compute thermally averaged drift velocities from the Fokker-Planck equation that describes the nonzero-temperature dynamics of the domain wall. As special limits of this general description, we describe rigid domain walls as well as vortex domain walls. In these limits, we also determine depinning times of the domain wall from an extrinsic pinning potential. We compare our theory with previous theoretical and experimental works.