  We study non-local correlations in a three-orbital Hubbard model defined on
an extended one-dimensional chain using determinant quantum Monte Carlo and
density matrix renormalization group methods. We focus on a parameter with
robust Hund's coupling, which produces an orbital selective Mott phase (OSMP)
at intermediate values of the Hubbard U, as well as an orbitally ordered
ferromagnetic insulating state at stronger coupling. An examination of the
orbital and spin-correlation functions indicates that the orbital ordering
occurs before the onset of magnetic correlations in this parameter regime as a
function of temperature. In the OSMP, we find that the self-energy for the
itinerant electrons is momentum dependent, indicating a degree of non-local
correlations while the localized electrons have largely momentum independent
self-energies. These non-local correlations also produce relative shifts of the
hole-like and electron-like bands within our model. The overall momentum
dependence of these quantities is strongly suppressed in the orbitally-ordered
insulating phase.
