Fig. 5

The schematic diagrams of electric current induced by spin diffusion and spin drift. a and c are schematic diagrams of electric current induced by spin diffusion corresponding to 1hh-1e and 1lh-1e, respectively. b and d are schematic diagrams of electric current induced by spin drift corresponding to 1hh-1e and 1lh-1e, respectively. In these four figures, the bigger black (white) dots with a black arrow denote spin-polarized electrons (holes), the red arrows denote the spin currents, the blue arrows denote the electric fields, and the green arrows denote the electric currents