Coulomb Correlations in Multi-Orbital Materials:
Na_xCoO_2 and Ca_xSr_2-xRuO_4
ABSTRACT: The dynamical mean field theory is used to describe Coulomb interactions in strongly correlated transition metal oxides. In particular, we discuss the modification of the Fermi Surface of Na_xCoO_2 caused by inter-orbital charge transfer and the nature of the Mott transition in Ca_xSr_2-xRuO_4. The theoretical results are compared with recent angle-resolved photoemission measurements on these systems.