Magnetised Foil as a Spin Filter

Abstract

The elastic transmission of low-energy spin-polarised electrons through thin ferromagnetic films is treated in terms of elastic forward scattering of electrons. General symmetry arguments are used to derive the interaction operator which governs the process. Experimental results reported to date rule out spin-exchange scattering of the projectile electrons as a mechanism for the spin filtering action. The analogy of the observed rotation of the spin component normal to the magnetisation and Faraday effect in magneto-optics is discussed.