Evidence for strong Coulomb correlations in metallic phase of vanadium dioxide

The influence of Coulomb correlation on magnetic and spectral properties in metallic rutile phase of vanadium dioxide is studied by state of the art LDA+DMFT method. Calculation results in strongly correlated metallic state with an effective mass renormalization $m^*/m\approx2$. Uniform magnetic susceptibility shows Curie-Weiss temperature dependence with effective magnetic moment, $p_{\rm eff}^{\rm theor}=1.54\mu_B$, in a good agreement with the experimental value $p_{\rm eff}^{\exp}=1.53\mu_B$ that is close to ideal value for V$^{4+}$ ion with the spin $S=1/2$, $p_{eff} = 1.73 \mu_B$. Calculated spectral function shows well developed Hubbard bands observable in the recent experimental photoemission spectra. We conclude that VO$_2$ in rutile phase is strongly correlated metal with local magnetic moments formed by vanadium $d$-electrons.