Strong non-equilibrium effects in spin torque systems

Abstract

We consider a problem of persistent magnetization precession in a single domain ferromagnetic nano particle under the driving by the spin-transfer torque. We find that the adjustment of the electronic distribution function in the particle renders this state unstable. Instead, abrupt switching of the spin orientation is predicted upon increase of the spin-transfer torque current. On the technical level, we derive an effective action of the type of Ambegaokar-Eckern-Schön action for the coupled dynamics of magnetization (gauge group $SU(2)$) and voltage (gauge group $U(1)$).

14 pages, 3 figures

References in corpus (6)

• Spin-torque switching: Fokker-Planck rate calculation
• Spin-torque shot noise in magnetic tunnel junctions
• Tunnel-barrier-enhanced dc voltage signals induced by magnetization dynamics in magnetic tunnel junctions
• Geometric Quantum Noise of Spin
• Tunnelling density of states at Coulomb blockade peaks
• Stochastic dynamics of magnetization in a ferromagnetic nanoparticle out of equilibrium