Ab initiomagneto-optical properties of bccNi∕Ni(100)

Abstract

The inter- and intralayer contributions to the layer-resolved complex optical conductivity tensor for semi-infinite layered systems are calculated in terms of the Luttinger formula within the spin-polarized relativistic screened Korringa-Kohn-Rostoker method. Ab initio Kerr angles are then obtained for arbitrary geometry and incidence via a $2\ifmmode\times\else\texttimes\fi{}2$ matrix technique including all multiple reflections and all optical interferences. Applied to in-plane single-domain magnetized bcc $\mathrm{Ni}∕\mathrm{Ni}(100)$, it is proven that the assumed appropriate formula of Kerr angles widely used to explain magneto-optical Kerr effect with rotating magnetic field measurements fully agrees with our ab initio Kerr data. From the experimental Kerr data of Tian et al. [Phys. Rev. Lett. 94, 137210 (2005)], however, it cannot be concluded that the deduced magnetic properties apply for bulk Ni, since about 75% of the contributions to the Kerr rotation angle arise from the surface.