Spin Torque Effects in Magnetic Systems

This chapter focuses on the spin-transfer-torque (STT) phenomenon which refers to a novel method to actively control and manipulate magnetic moments, or spins, using an electrical current. It discusses a variety of STT devices from point contacts to nanopillars and nanowires. Giant magnetoresistance originates from the spin-dependent scattering that occurs when electrons move across the multilayer film. STT phenomenon currently attracts a great deal of attention because it combines interesting fundamental science with the promise of applications in a broad range of technologies. Nanoscale electrical contacts are convenient tools for the realization of local injection and detection of conduction electrons in experimental studies of electron kinetics in metals. In addition to being inexpensive and simple to control, the mechanical system provides a unique means to produce a contact of only a few nanometers in size and to change the contact within a single experimental run by simple rotation of the room-temperature control knob.