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

TL;DR

This study uses high-precision quantum Monte Carlo simulations within dynamical mean field theory to reveal two consecutive orbital-selective Mott transitions in an anisotropic two-orbital Hubbard model, even without spin-flip or pair-hopping terms.

Contribution

It demonstrates the existence of two orbital-selective Mott transitions in the model without spin-flip or pair-hopping, extending previous work to lower temperatures.

Findings

Identification of two consecutive OSMTs in the model

Analysis of self-energy and spectral functions to detect transitions

Discussion of the nature and order of the Mott transitions

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.