Spin-polarized transport in diluted GaMnAs/AlAs/GaMnAs ferromagnetic semiconductor tunnel junctions

Taking into account the basic physics of diluted ferromagnetic semiconductors (DMS), in which the variation of the splitting energy with temperature is included, we apply a quantum-mechanical approach to studying the spin-polarized transport in GaMnAs/AlAs/GaMnAs DMS tunnel junctions. It is shown that tunneling magnetoresistance first rapidly increases and then decreases with increasing barrier thickness, exhibiting a peak at an optimum value of barrier thickness. We also find that the normalized conductance difference decreases with the enhancement of temperature. The theoretical results can reproduce the main feature of the experiments. (C) 2004 American Institute of Physics.