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.