Spin injection and spin transport in hybrid nanostructures

This chapter describes the basics of spin injection and spin transport in magnetic nanohybrid structures. Particular emphasis is placed on the nonlocal spin transport in a spin injection and detection device of F1/N/F2 structure, where F1 is a spin injector, N is a nonmagnetic metal or semiconductor, and F2 is a spin detector. The spin-dependent transport equations for the electrochemical potentials of up and down spins are solved, and the efficient spin injection, spin accumulation, spin current, spin transfer, and spin detection are examined in the structure of arbitrary junction resistance, its source ranging from a metallic contact to a tunneling regime. It is demonstrated that discussion concerning the nonlocal spin-injection devices provide opportunities to relate novel phenomena, such as pure spin-current injection and manipulation, spin injection into superconductors or semiconductors, and spin Hall effect in nanohybrid stuctures.