Magnetic circular dichroism in photoemission by linear polarized light

For light in a general state of polarization incident in a general direction on a ferromagnetic cubic (001) surface, magnetic dichroism and spin polarization in valence-band photoemission normal to the surface are investigated analytically and numerically, taking into account the optical response of the solid in the classical Fresnel approximation. Evaluation of relativistic dipole matrix elements leads to explicit expressions which reveal details of the underlying physical mechanisms and provide general semiquantitative results. Using a fully relativistic Green function method, numerical results have been obtained for fct Ni(001) with magnetization perpendicular and parallel to the surface. For perpendicular magnetization and linearly polarized light with the electric field vector rotated out of the incidence plane, the optical response leads to substantial magnetic dichroism, the spectral shape of which is the same as in the case of circular polarization of the incident light.