Thermally driven spin transfer torque system far from equilibrium: Enhancement of thermoelectric current via pumping current

摘要

We consider a small itinerant ferromagnet exposed to an external magnetic field and strongly driven by a thermally induced spin current. For this model, we derive the quasiclassical equations of motion for the magnetization where the effects of a dynamical nonequilibrium distribution function are taken into account self-consistently. We obtain the Landau-Lifshitz-Gilbert equation supplemented by a spin-transfer torque term of Slonczewski form. We identify a regime of persistent precessions in which we find an enhancement of the thermoelectric current by the pumping current.