Current noise generated by spin imbalance in presence of spin relaxation
V. S. Khrapai+*, K. E. Nagaev+×
+Institute of Solid State Physics RAS, 142432 Chernogolovka, Russia
*Moscow Institute of Physics and Technology, 141700 Dolgoprudny, Russia
×Kotelnikov Institute of Radioengineering and Electronics, 125009 Moscow, Russia
Abstract
We calculate current (shot) noise in a metallic
diffusive conductor generated by spin imbalance in the absence of a net
electric current. This situation is modeled in an idealized
three-terminal setup with two biased ferromagnetic leads (F-leads)
and one normal lead (N-lead). Parallel magnetization of the
F-leads gives rise in spin-imbalance and finite shot noise at
the N-lead. Finite spin relaxation results in an increase of the
shot noise, which depends on the ratio of the length of the
conductor (L) and the spin relaxation length (ls). For
the shot noise increases by a factor of two and
coincides with the case of the anti-parallel magnetization
of the F-leads.