Poster Specular to Diffusive Scattering in Fe/MgO/Fe Magnetic Tunnel Junctions

Nanoelectronic device properties are usually influenced rather strongly by impurities and atomistic disorder. Examples are electron scattering by dopants in semiconductor nano-wires, spin scattering by disorder in magnetic tunnel junctions, and spin polarized current in dilute magnetic semiconductors. Theoretically, any calculated transport quantity must be averaged over the ensemble of possible impurity configurations. There has been no theoretical formalism and computational tool that can effectively carried out disorder averaging for nonequilibrium quantum transport problems. In this poster presentation, we report our recently developed formalism and numerical implementation of the non-equilibrium vertex correction (NVC) theory which is a first principles solution of the nonequilibrium impurity average problem for quantum transport. We apply this theory to investigate effects due to oxygen vacancy to spin polarized quantum transport in magnetic tunneling junction (MTJ) Fe/MgO/Fe.