Influence of electronic correlations on orbital polarizations in the parent and doped iron pnictides

TL;DR

This study investigates how electronic correlations influence orbital polarization in iron pnictides, revealing a wide doping range of magnetic phases and polarization reversal driven by Coulomb interactions.

Contribution

It provides a systematic analysis of orbital polarization across different correlation strengths using the KRSB approach, highlighting the effects of doping and crystal field splitting.

Findings

Orbital polarization persists over a wide doping range.

Reversal of orbital polarization occurs at intermediate correlations.

Small crystal field splitting enhances orbital density wave order.

Abstract

Orbital polarization and electronic correlation are two essential aspects in understanding the normal state and superconducting properties of multiorbital FeAs-based superconductors. In this Letter, we present a systematical study on the orbital polarization of iron pnictides from weak to strong Coulomb correlations within the KRSB approach. The magnetic phase diagram of the two-orbital model for LaFeAsO clearly shows that the striped antiferromagnetic metallic phase with considerable orbital polarization exists over a wide doping range. The reversal of the orbital polarization occurs in the intermediate correlation regime.A small crystal field splitting enhances the orbital density wave order.