Multiorbital Hubbard model in infinite dimensions: Quantum Monte Carlo calculation

Using the quantum Monte Carlo technique we compute thermodynamics and spectra for the orbitally degenerate Hubbard model in infinite spatial dimensions. With increasing orbital degeneracy we find in the one-particle spectra broader Hubbard bands (consistent with increased kinetic energy), a narrowing Mott gap, and increasing quasiparticle spectral weight. Hund’s rule exchange coupling decreases the critical on-site Coulomb energy for the Mott transition. The metallic regime resistivity for twofold degeneracy is quadratic in temperature at low temperatures.