Abstract

We consider persistent precessions of an itinerant single domain nano-magnet driven by a thermally induced spin-transfer torque current. In [1] it was found that, far from equilibrium, stationary adjustments of the electronic distribution functions can render electrically driven persistent precessions unstable. In contrast, as we now show, stable persistent precessions can be maintained by thermal driving even far from equilibrium. Interestingly, to obtain consistent results for the stability, we have to include dynamic adjustments of the distribution function to the trajectory of the magnetization. On the technical level, we follow the approach of [1], i.e., we derive an effective action of the Ambegaokar-Eckern-Schön type for the magnetization. To determine the stability, we have to extend the calculations of [1] and include higher orders terms.

[1] T. Ludwig, I. S. Burmistrov, Y. Gefen, A. Shnirman Phys. Rev. B 95, 075425 (2017)