Microscopic Theory of the Inverse Edelstein Effect

We provide a precise microscopic definition of the recently observed inverse Edelstein effect in which a nonequilibrium spin accumulation in the plane of a two-dimensional (interfacial) electron gas drives an electric current perpendicular to its own direction. The drift-diffusion equations that govern the effect are presented and applied to the interpretation of the experiments.

Figure 1

Schematic description of the Rashba model and of the generation of a spin current from injected spin in the $y$ direction. The thick arrows denote the Rashba field around which the spin (thin arrow) precesses. The two insets (a) and (b) zoom in on the dynamics of the spin near points (0, $k_F$) and (0, $-k_F$) in momentum space. In the first case the spin, initially pointing in the $y$ direction, acquires a positive $z$ component and travels in the $+y$ direction. In the second case, the spin acquires a negative $z$ component and travels in the $-y$ direction.