EVOLUTION OF SPECTRAL-FUNCTION IN A DOPED MOTT INSULATOR - SURFACE VSBULK CONTRIBUTIONS

We study the evolution of the spectral function with progressive hole doping in a Mott insulator, La1-xCaxVO3 with x = 0.0-0.5. The spectral features indicate a bulk-to-surface metal-insulator transition in thi s system. Doping dependent changes in the bulk electronic structure ar e shown to be incompatible with existing theoretical predictions. An e mpirical description based on the single parameter U/W is shown to des cribe consistently the spectral evolution.