Magnetization switching due to nonlocal spin injection

This chapter discusses and presents a schematic illustration of nonlocal spin injection. In this case, the spin-polarized electrons are injected from the ferromagnet and are extracted from the left-hand side of the nonmagnet. This results in the accumulation of nonequilibrium spins in the vicinity of the F/N junctions. Since the electrochemical potential on the left-hand side is lower than that underneath the F/N junction, the electron flows by the electric field. On the right-hand side, although there is no electric field, the diffusion process from the nonequilibrium into the equilibrium state induces the motion of the electrons. Since the excess up-spin electrons exist underneath the F/N junction, the up-spin electrons diffuse into the right-hand side. On the other hand, the deficiency of the down-spin electrons induces the incoming flow of the down-spin electrons opposite to the motion of the up-spin electron.