Orbital-selective Mott transitions in two-band Hubbard models

Nils Blümer, Carsten Knecht, Krunoslav Požgajčić, Peter G.J. van Dongen
2007 Journal of Magnetism and Magnetic Materials  
The anisotropic two-orbital Hubbard model is investigated at low temperatures using high-precision quantum Monte Carlo (QMC) simulations within dynamical mean-field theory (DMFT). We demonstrate that two distinct orbital-selective Mott transitions (OSMTs) occur for a bandwidth ratio of 2 even without spin-flip contributions to the Hund exchange, and we quantify numerical errors in earlier QMC data which had obscured the second transition. The limit of small inter-orbital coupling is introduced
more » ... ia a new generalized Hamiltonian and studied using QMC and Potthoff's self-energy functional method, yielding insight into the nature of the OSMTs and the non-Fermi-liquid OSM phase and opening the possibility for a new quantum-critical point.
doi:10.1016/j.jmmm.2006.10.525 fatcat:2tav2blpfrb7pitrddqzlyjttq