Spin-dependent electron transport at the ferromagnet/semiconductor interface

A search for spin-dependent electron transport at the ferromagnet/semiconductor interface has been made by measuring the bias dependence of a photon excited current through the interface. A circularly polarized laser beam was used to excite electrons with a spin polarization perpendicular to the film plane. In samples of the form 3 nm Au/5 nm Ni80Fe20/GaAs (110), a significant transport current was detected with a magnitude dependent on the relative orientation of the spin polarization and the magnetization vector. At perpendicular saturation, the bias dependence of the photocurrent is observed to change in the range 0.7-0.8 eV when the helicity is reversed. (C) 1999 American Institute of Physics. [S0021-8979(99)26508-5].