Electronic structure of paramagnetic V₂O₃: Strongly correlated metallic and Mott insulating phase

The computation scheme merging the local density approximation and the dynamical mean-field theory (DMFT) is employed to calculate spectra both below and above the Fermi energy and spin and orbital occupations in the correlated paramagnetic metallic and Mott insulating phase of V₂O₃. The self-consistent DMFT equations are solved by quantum Monte Carlo simulations. Room-temperature calculations provide direct comparison with experiment. They show a significant increase of the quasiparticle height in comparison with the results at 1160 K. We also obtain new insights into the nature of the Mott-Hubbard transition in V₂O₃. Namely, it is found to be strikingly different from that in the one-band Hubbard model due to the orbital degrees of freedom. Furthermore, we resolve the puzzle of the unexpectedly small Mott gap in Cr-doped V₂O₃.