As indicated above, Quantum Monte Carlo (QMC) simulations constitute the most important numerical method we employ. Within the group, Professor Nils Blümer and his collaborators are to a large extent specialized on high-precision applications of this method. With the use of the Quantum Monte Carlo technique (possibly in combination with the Maximum Entropy method) we have in the past been successful in determining static and dynamic properties of single band Hubbard models. Recently, most Quantum Monte Carlo simulations performed by the group were for multiband models.
Two examples are the article Knecht et al., in which it was shown numerically for a half-filled two-band model with spin dependent kinetic energy that two separate, consecutive metal-insulator transitions occur in the two orbitals of this model. As an extension, it was shown in Jakobi et al. that this phenomenon also occurs for doped systems (i.e., away from half-filling):
Orbital-selective Mott transitions in the anisotropic two-band Hubbard model at finite temperatures
C. Knecht, N. Blümer, and P. G. J. van Dongen
Phys. Rev. B 72, 081103(R) (2005)
Orbital-selective Mott transitions in a doped two-band Hubbard model
E. Jakobi, N. Blümer and P.G.J. van Dongen
Physical Review B, vol. 80, Issue 11, id. 115109 (2009)
Orbital-selective Mott transitions in a doped two-band Hubbard model with crystal field splitting
E. Jakobi, N. Blümer, and P. G. J. van Dongen
Phys. Rev. B 87, 205135 (2013)