Berlin 2005 – wissenschaftliches Programm

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MA: Magnetismus

MA 12: Elektronentheorie

MA 12.6: Vortrag

Samstag, 5. März 2005, 10:15–10:30, TU EMH225

Accountig for many-body correlation effects in the calculations of the x-ray photoemission and magneto-optical properties of transition metals — •Stanislav Chadov, Jan Minar, Alexander Perlov, and Hubert Ebert — Department Chemie, University of Munich, Butenandstr. 5-13, D-81377 Munich, Germany

Calculations of valence band photoemission spectra on the basis of the LDA have been very succesfull in the past for many transition metal systems. However it is well known that correlation effects play for some materials a rather crucial role. Fortunately, it is often well justified to represent these by a local (site-diagonal) self-energy. In this case correlation effects can straightforwardly be incorporated within calculations based on the one-step model of photoemission. This applies in particular for its spin-polarised relativistic version that allows to deal with the Fano-effect and magnetic dichroism. Corresponding results will be presented for transition metal systems, for which the pure Fano-effect, that means the spin-polarisation of the photo-current due to spin-orbit coupling has been investigated. Results of investigations on the spontanous spin-polarisation in the ground-state by means of spin-resolved VB-XPS will be presented for the half-metallic ferromagnet NiMnSb. In addition, influence of correlation effects on the magneto-optical properties of Fe, Co and Ni will be presented. Within these investigations correlation effects are accounted for via the self-energy calculated by the recently proposed LDA+DMFT scheme (dynamical mean field theory). As it turns out, taking correlation effects into account the agreement between theory and experiment is significantly improved.