Evolution of spectral function in a doped Mott insulator : surface vs.   bulk contributions
  We study the evolution of the spectral function with progressive hole doping in a Mott insulator, $La_{1-x}Ca_xVO_3$ with $x$ = 0.0 - 0.5. The spectral features indicate a bulk-to-surface metal-insulator transition in this system. Doping dependent changes in the bulk electronic structure are shown to be incompatible with existing theoretical predictions. An empirical description based on the single parameter, $U/W$, is shown to describe consistently the spectral evolution. 
K. Maiti, Priya Mahadevan, and D.D. Sarma (Solid State and Structural   Chemistry Unit Indian Institute of Science, Bangalor...