Fig. 1: Sketch of the MTJ. The barrier (3 monolayers MgO) is sandwiched by two ferromagnetic layers (FexCo1-x) and connected to semi-infinite Cu leads, which are in the bcc-Fe structure. One ferromagnetic layer is the fixed layer (10 monolayers), whereas the other is the free layer (5 monolayers). The relavite angle between the two magnetizations ML and MR of the two layers is given by Θ. The torque acting on the magnetization of the free layer can be decomposed into an in-plane and out-of-plane component.