Scattering theory of magnetic/superconducting junctions with spin active   interfaces
  We formulate a generalized scattering field theory a la Buttiker describing particles transport in magnetic/superconducting heterostructures. The proposed formalism, characterized by a four- component spinorial wavefunction of the Bogoliubov de Gennes theory, allows to describe the spin flipping phenomena induced by noncollinear magnetizations in the scattering region. As a specific application of the theory, we analyze the conductance, the magnetoresistance and the generation of spin-torque produced by an applied voltage in a spin-valve system. Quantum size effects and quantum beating patterns both in the conductance and in the spin-torque are carefully described. 
F. Romeo and R. Citro
cond-mat.mes-hall cond-mat.supr-con