The Gutzwiller theory for transition metals and their compounds
Dr. Jörg Bünemann (Universität Marburg)

The Gutzwiller theory has been developed in recent years to investigate realistic multi-band Hubbard models, which describe the electronic and magnetic properties of transition metals and their compounds. The Gutzwiller method allows the study of ground-state properties as well as single and two-particle excitations. It requires only a modest numerical effort for the investigation of complex multi-band systems as compared to, e.g., the dynamical mean field theory. Therefore, rather subtle effects can be studied. In the first part of my talk, I will give a thorough introduction into the Gutzwiller theory. In the second part, I present our results for the electronic and magnetic properties of ferromagnetic nickel and for the cobaltates Na_xCO_2.