Surface vs Bulk Coulomb Correlations in Perovskites

Ansgar Liebsch
Research Center Juelich, Germany

    Photoemission spectra of the perovskites SrVO3, SrRuO3 and LaVO3 indicate that Coulomb correlations at the surface are stronger than in the bulk. Using the multi-orbital dynamical mean field theory we show that the reduced coordination of surface atoms leads to a shift of spectral weight from the coherent peak near EF to the lower and upper Hubbard bands. The possibility of separate surface/bulk metal-insulator transitions in Ca,LaVO3 is discussed. No evidence is found for orbital-dependent metal-insulator transitions in the layer ruthenate Ca,Sr2RuO4.
 
Date:  
Tuesday, March 11, 2003
12:00 noon, room 260, Wright-Rieman Chemistry Laboratory
Lunch:  11:45 a.m.