Magnetization noise in magnetoelectronic nanostructures.
By scattering theory we show that spin current noise in normal electric conductors in contact with nanoscale ferromagnets increases the magnetization noise by means of a fluctuating spin-transfer torque. Johnson-Nyquist noise in the spin current is related to the increased Gilbert damping due to spin pumping, in accordance with the fluctuation-dissipation theorem. Spin current shot noise in the presence of an applied bias is the dominant contribution to the magnetization noise at low temperatures.
Foros
Jørn
J
Department of Physics, Norwegian University of Science and Technology, 7491 Trondheim, Norway.
Brataas
Arne
A
Tserkovnyak
Yaroslav
Y
Bauer
Gerrit E W
GE