Orbital-selective Mott phase from a dehybridization in a multiorbital Hubbard model

In multi-orbital systems, certain orbitals can become Mott localized, leading to an orbital-selective Mott phase (OSMP) that is of considerable current interest in the field of iron-based superconductors. Here, we consider the OSMP in the presence of an inter-orbital hopping term. The stability of the OSMP against an interorbital has been demonstrated using an auxiliary spin method [1,2,3], but has yet to be shown in methods based on the dynamical mean field theory [4].

In this work, we use the extended-DMFT (EDMFT) method so that inter-unit-cell correlation effects are taken into consideration. We solve the EDMFT equations with a continuous time quantum Monte Carlo method. An OSMP develops in the presence of the inter-unit-cell spin correlation, through a mechanism suggested by a recent renormalization-group analysis [5]. Implications of our results for the overall physics of iron-based superconductors are discussed.