Implementation of a nonequilibrium Green’s function method to calculate spin-transfer torque

Abstract
We present an implementation of the steady state Keldysh approach in a Green’s functionmultiple scattering scheme to calculate the nonequilibrium spin density. This density is used to obtain the spin-transfer torque in junctions showing the magnetoresistance effect. We use our implementation to study the spin-transfer torque in metallic Co ∕ Cu ∕ Co junctions.