A possibility of increasing spin injection efficiency in magnetic   junctions
  Nonequilibrium electron spin polarization is calculated under spin injection from one ferromagnet to another in magnetic junction. It is shown that the nonequilibrium spin polarization can be comparable with equilibrium one if the material parameters are chosen appropriately. This leads to lowering the threshold current density necessary for the junction switching and opens a perspective to creating THz laser based on the spin-polarized current injection. 
E. M. Epshtein, Yu. V. Gulyaev, P. E. Zilberman, A. I. Krikunov