Thursday's seminar

[CM ICTP - Trieste]

SEMINAR on   Disorder and strong electron correlations



Thursday, 19 February      -  11:00 a.m.



Seminar Room,  Leonardo Building - first floor



A. CHUDNOVSKIY    ( University of Hamburg )



"Spin-torque shot noice in   magnetic tunnel junctions"



Abstract



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.