High-resolution photoemission study of V2-yO3

High-resolution photoemission spectroscopy (HRPES) was performed on V2-yO3 (y=0.00, 0.03, and 0.04), which lias been considered as the prototype of the Mott-Hubbard model for the metal-insulator transition (MIT). The density of states at the Fermi level (E-F) observed by HRPES is one order of magnitude smaller than that of the band calculation based on the local-density approximation. We observed no distinguishable sharp structure at E-F for hole-doped V1.96O3 at 15 K as well as negligible temperature-dependence of the HRPES spectrum of V2O3 between 200 and 300 K. The analysis of the V 3d spectrum with a local self-energy gives a too large quasiparticle effective mass compared to the specific-heat measurement, which implies the importance of spatial fluctuations near the MIT. All these facts strongly question the applicability of the dynamical mean-field theory of the Hubbard model to the V2-yO3 system.