Spin-Polarized Electronic Transport Properties of Tunneling Junctions

Yun Li and Patrick Bruno

Giant magnetoresistance(GMR) in magnetic multilayers has continuously attracted much attention since its discovery. Due to the high field sensitivity, there are growing experimental and theoretical interests in the study of electronic transport properties and tunneling through magnetic junctions, in which two ferromagnets are separated by a thin insulator (semiconductor) layer. Recent progress in tunneling magnetoresistance (TMR) has demonstrated that tunnel junctions are very promising from the point of view of applications as nonvolatile magnetic random access memories with high impedance and low interlayer coupling.

Our research is currently focused on the effects of disorder and spin-relaxation on the transport properties due to magnetic impurities and spin-orbit scattering. The calculations are based on Keldysh formalism together with the recursion method for calculating the real-space Green's function within the tight-binding model. This model is capable of taking into account realistic electronic structures and dealing with more complicated junctions.