Coulomb Correlations in Multi-Orbital Materials:

Na_xCoO_2 and Ca_xSr_2-xRuO_4

 

Ansgar Liebsch

Research Center Juelich, Germany

 

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.