Effects of correlation in LiFeAs

TL;DR

This study investigates how electronic correlations, especially Hund's coupling, influence the electronic structure of LiFeAs, revealing it as a moderately correlated metal with Fermi surface modifications consistent with experimental observations.

Contribution

It demonstrates the impact of Hund's rule coupling on correlation strength and Fermi surface topology in LiFeAs using combined DFT and DMFT calculations.

Findings

LiFeAs is a moderately correlated metal.

Hund's coupling J controls correlation strength.

Fermi surface hole pockets change with correlations.

Abstract

We discuss the role of electronic correlations in the iron-based superconductor LiFeAs by studying the effects on band structure, mass enhancements, and Fermi surface in the framework of density functional theory combined with dynamical mean field theory calculations. We conclude that LiFeAs shows characteristics of a moderately correlated metal and that the strength of correlations is mainly controlled by the value of the Hund's rule coupling J. The hole pockets of the Fermi surface show a distinctive change in form and size with implications for the nesting properties. Our calculations are in good agreement with recent angle-resolved photoemission spectroscopy and de Haas-van Alphen experiments.