Spin-dependent transport in trilayer junctions of doped manganites

Trilayer junctions of doped manganites provide a model system for the study of spin-polarized transport across a half metallic interface. Novel phenomena observed in these systems include a large low-field magnetoresistance (MR), with nearly an order of magnitude change in junction resistance in 100 Oe at 14 K, and a strong temperature and bias dependence of the junction MR. They also enabled the first demonstration of a spin-angular momentum transfer-induced reversal of a magnetic moment. Systems containing both manganite and transition metal ferromagnetic electrodes demonstrate a complex interface structure between the perovskite oxide such as SrTiO3 and the transition metal electrode such as Co or Fe. It reveals the important effect this interface has on the magnetotransport property of the junction.