Theoretical description of the Fano effect in the angle-integrated valence-band photoemission of paramagnetic solids

A theoretical description of the Fano effect in the angle-integrated valence-band photoemission of paramagnetic solids is presented that is based on the one-step model of photoemission and relativistic multiple-scattering theory. Applications to fcc-Cu led to a very satisfying agreement with recent experimental data that show the Fano effect, i.e., a finite spin-polarization for the spectra is found for excitation with circularly polarized radiation. As can be demonstrated by model calculations. this finding is caused by the presence of spin-orbit coupling. To allow for a more detailed discussion of the spectra a simplified description of the Fano effect is presented that treats spin-orbit coupling as a perturbation