Abstract:
A new technique has been implemented for realistic electronic structure calculations of f-electron systems with moderately strong correlations. The technique is based on the dynamical mean field theory (DMFT) with a perturbative treatment of effective quantum impurity problem using a spin-polarized version of the T-matrix in combination with the fluctuating exchange approximation (SPTF). The present many-body approach properly includes effects of strong spin-orbit coupling. This technique has been applied to a number of actinide compounds, including the Pu delta phase, Pu and U monochalcogenides, the PuCoGa₅ and UGe₂ superconductors. We have obtained both magnetic and spectral properties of these compounds in good agreement with experiment. By taking into account dynamical correlations within the DMFT one is able to reproduce some characteristic many-body features in photoemission spectra of Pu-based compounds, namely the 'three-peak' structure observed in the non-magnetic δ-Pu and Pu monochalcogenides, as well as characteristic narrow peak at the Fermi level in PuCoGa₅.