Seminar on Disorder and strong electron correlations: "Spin-torque shot noise in magnetic tunnel junctions"
Starts 19 Feb 2009 11:00
Ends 19 Feb 2009 20:00
Central European Time
Leonardo da Vinci Building Seminar Room
Strada Costiera, 11
I - 34151 Trieste (Italy)
A spin polarized current may transfer angular momentum to a ferromagnet, resulting in a spin-torque phenomenon. At the same time the shot noise, associated with the current, leads to a nonequilibrium stochastic force acting on the ferromagnet. We derive a stochastic version of the Landau-Lifshitz-Gilbert equation for a magnetization of a "free" ferromagnetic layer in contact with a "fixed" ferromagnet. We solve the corresponding Fokker-Planck equation and show that the nonequilibrium noise yields to a nonmonotonic dependence of the precession spectrum linewidth on the current.