Precession of conduction-electron spins near an interface between normal and magnetic metals

A current crossing the interface between a ferromagnetic layer F ₁ and a normal layer N induces a magnetization in the conduction-electron gas near the interface. This “spin-injection” manifests itself as a DC voltage between N and a second ferromagnetic layer F₂ deposited on N. We treat the case where the magnetizations of F₁ and F₂ are perpendicular. The spin <s&oarr;> of injected conduction electrons precesses around the exchange field present in F₂. As a result, the direction of the local conduction-electron spin density in F ₂ is a function of the distance from the N-F₂ interface