Spin filtering and magnetoresistance in ballistic tunnel junctions - art. no. 195319

We theoretically investigate magnetoresistance (MR) effects in connection w ith spin filtering in quantum-coherent transport through tunnel junctions b ased on nonmagnetic/semimagnetic heterostructures. We find that spin filter ing in conjunction with the suppression/enhancement of the spin-dependent F ermi seas in semimagnetic contacts gives rise to (i) spin-split kinks in th e MR of single barriers and (ii) a robust beating pattern in the MR of doub le barriers with a semimagnetic well. We believe these are unique signature s for quantum filtering.