Evidence for strong Coulomb correlations in metallic phase of vanadium dioxide

TL;DR

This study demonstrates that the metallic rutile phase of vanadium dioxide exhibits strong Coulomb correlations, leading to a correlated metallic state with magnetic and spectral properties consistent with experimental observations.

Contribution

The paper provides the first detailed LDA+DMFT analysis showing strong Coulomb correlations and local magnetic moments in the metallic phase of VO2, aligning theory with experimental data.

Findings

Effective mass renormalization m*/m ≈ 2

Magnetic susceptibility follows Curie-Weiss law with p_eff ≈ 1.54 μ_B

Spectral function shows Hubbard bands matching photoemission spectra

Abstract

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, $p_{eff}^{theor} = 1.54 \mu_B$, in a good agreement with the experimental value $p_{eff}^{exp} = 1.53 \mu_B$ 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 observabale in the recent experimental photoemission spectra. We conclude that VO2 in rutile phase is strongly correlated metal with local magnetic moments formed by vanadium $d$-electrons.