  Ca1-xSrxVO3 is a Mott-Hubbard-type correlated electron system whose bandwidth
can be varied by the V-O-V bond angle, but the actual effect of bandwidth
control on the electronic structure has been controversial in previous
photoemission experiments. In this work, band dispersions and Fermi surfaces of
SrVO3 and CaVO3 are studied by angle-resolved photoemission spectroscopy. Near
the Fermi level (EF), three bands forming cylindricalFermi surfaces derived
from the three V 3d t2g orbitals have been observed. The observed band widths
for both compounds are almost half of those predicted by
local-density-approximation band-structure calculation, confirming mass
renormalization caused by electron correlation. It has been clearly
demonstrated that the width of the d band in CaVO3 is narrower than that in
SrVO3, qualitatively consistent with the result of band-structure calculation.
Roles of the orthorhombic lattice distortion and electron correlation in the
observed band narrowing are discussed.
