Orbital-selective Mott transitions in the 2-band J_z-model: a high-precision quantum Monte Carlo study

Abstract

Using high-precision quantum Monte Carlo (QMC) simulations within the framework of dynamical mean field theory (DMFT), we show that the anisotropic degenerate two-orbital Hubbard model contains two consecutive orbital-selective Mott transitions (OSMTs) even in the absence of spin-flip terms and pair-hopping processes. In order to reveal the second transition we carefully analyze the low-frequency part of the self-energy and the local spectral functions. This paper extends our previous work to lower temperatures. We discuss the nature - in particular the order - of both Mott transitions and list various possible extensions.