We investigate the effects of crystal field splitting in a doped two-band Hubbard model with different bandwidths within dynamical mean-field theory (DMFT), using a quantum Monte Carlo impurity solver. In addition to an orbital-selective Mott phase (OSMP) of the narrow band, which is adiabatically connected with the well-studied OSMP in the half-filled case without crystal field splitting, we find, for sufficiently strong interaction and a suitable crystal field, also an OSMP of the wide band. We establish the phase diagram (in the absence of magnetic or orbital order) at moderate doping as a function of interaction strength and crystal field splitting and show that also the wide-band OSMP is associated with non-Fermi-liquid behavior in the case of Ising type Hund rule couplings. Our numerical results are supplemented by analytical strong-coupling studies of spin order and spectral functions at integer filling.
@article{arxiv.1301.7252,
title = {Orbital-selective Mott transitions in a doped two-band Hubbard model with crystal field splitting},
author = {E. Jakobi and N. Blümer and P. G. J. van Dongen},
journal= {arXiv preprint arXiv:1301.7252},
year = {2013}
}
Comments
9 pages, 4 figures; version accepted for Phys. Rev. B