TUNNELING MAGNETORESISTANCE IN FERROMAGNETIC SEMICONDUCTOR TUNNEL JUNCTIONS

Abstract

Taking into account the basic physics of diluted ferromagnetic semiconductors (DMS), we use the tunneling Hamiltonian approach to studying the spin-polarized transport in GaMnAs / AlAs / GaMnAs DMS tunnel junctions. It is found that the splitting, Fermi energies, and the hole concentration for a fixed Mn impurity density vary with temperature, which exert a great influence on the spin-polarized transport of the DMS. We have also shown that there exists a spin-flip tunneling process arising from the impurity Mn scattering in the barrier, and the variation of normalized conductance difference ΔG with temperature is consistent with that of experiment.