Effects of disorder in magnetic tunnel junctions

Summary form only given. The influences of barrier random disorder on tunnel conductance (TC) and magnetoresistance (TMR) in ferromagnet (FM)/insulator(semiconductor) (I(S))/FM junctions are investigated theoretically taking into account spin-orbit (SO) coupling. The TMR decreases significantly due to the spin-flip (SF) scattering caused by the SO coupling. We have found that the SF scattering is much stronger for antiparallel configuration of magnetization due to the reversal of the spin dependence of the final DOS in the spin-flip processes and the TMR can even be inversed when the SF scattering is beyond some critical point. The numerical calculations are performed within the single-orbital tight-binding model using the recursive Green´s function method based on the extended Landauer-Buttiker formula.