ABSTRACT
This chapter discusses noise in metallic spintronic devices, paying
main attention on spin valves (SVs) which are common for high
current and relatively high dissipation spintronic applications.
Noise in some other metallic structures such as exchange-coupled
multilayerswill also be discussed. Themain advantage ofmetallic SV
is their robustness respect the possible external damage (radiation,
current peaks, etc.)
Soon after GMR effect was discovered in the antiferromagnetically
coupled multilayers, Hardner et al. considered the applicability
of FDT to these early stage spintronic devices (Hardner et al.,
1993b). The goal was to investigate link between fluctuations of the
magneticmoment of the electrodes (linked through FDT to the out of
equilibrium characteristic known as imaginary contribution to the
magnetic susceptibility) and fluctuations of the device resistance.
The simplest form of such relation could be written as (Hardner
et al., 1993b)
