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 via 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.
@article{arxiv.cond-mat/0609758,
title = {Orbital-selective Mott transitions in two-band Hubbard models},
author = {N. Blümer and C. Knecht and K. Pozgajcic and P. G. J. van Dongen},
journal= {arXiv preprint arXiv:cond-mat/0609758},
year = {2015}
}
Comments
2 pages, 4 figures, presented at ICM2006 and accepted for JMMM