Dynamics of spin proximity polarization in a hybrid ferromagnet/semiconductor structure

Abstract

We study theoretically dynamics of spin proximity polarization of semiconductor electrons in a hybrid ferromagnet/semiconductor (F/S) structure. When the hybrid structure comes into equilibrium after a photoexcitation a spin current flowing through the interface produces a spin polarization of semiconductor electrons. In turn, a spin backflow arising in the thin semiconductor layer affects the interface spin current. We analyze the interplay of these processes by using the spin diffusion equation with appropriate boundary conditions at the F/S interface and show that the decay of the proximity polarization with time depends on the temporal behavior of the spin current emitted by the interface.