Mott-Hubbard Metal-Insulator Transition in ParamagneticV2O3: AnLDA+DMFT(QMC)Study

Abstract

The electronic properties of paramagnetic ${\mathrm{V}}_{2}{\mathrm{O}}_{3}$ are investigated by the computational scheme $\mathrm{LDA}+\mathrm{DMFT}(\mathrm{QMC})$. This approach merges the local density approximation (LDA) with dynamical mean-field theory (DMFT) and uses quantum Monte Carlo simulations (QMC) to solve the effective Anderson impurity model of DMFT. Starting with the crystal structure of metallic ${\mathrm{V}}_{2}{\mathrm{O}}_{3}$ and insulating $({\mathrm{V}}_{0.962}{\mathrm{Cr}}_{0.038}{)}_{2}{\mathrm{O}}_{3}$ we find a Mott-Hubbard transition at a Coulomb interaction $U\ensuremath{\approx}5\mathrm{eV}$. The calculated spectrum is in very good agreement with experiment. Furthermore, the orbital occupation and the spin state $S\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}1$ determined by us agree with recent polarization dependent x-ray-absorption experiments.