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.