English

Effect of non-local correlations on the electronic structure of LiFeAs

Strongly Correlated Electrons 2020-10-26 v3 Superconductivity

Abstract

We investigate the role of non-local correlations in LiFeAs by exploring an ab-initio-derived multi-orbital Hubbard model for LiFeAs via the Two-Particle Self-Consistent (TPSC) approach. The multi-orbital formulation of TPSC approximates the irreducible interaction vertex to be an orbital-dependent constant, which is self-consistently determined from local spin and charge sum rules. Within this approach, we disentangle the contribution of local and non-local correlations in LiFeAs and show that in the local approximation one recovers the dynamical-mean field theory (DMFT) result. The comparison of our theoretical results to most recent angular-resolved photoemission spectroscopy (ARPES) and de-Haas van Alphen (dHvA) data shows that non-local correlations in LiFeAs are decisive to describe the measured spectral function A(k,ω)A(\vec k,\omega), Fermi surface and scattering rates. These findings underline the importance of non-local correlations and benchmark different theoretical approaches for iron-based superconductors.

Keywords

Cite

@article{arxiv.1906.11853,
  title  = {Effect of non-local correlations on the electronic structure of LiFeAs},
  author = {Karim Zantout and Steffen Backes and Roser Valentí},
  journal= {arXiv preprint arXiv:1906.11853},
  year   = {2020}
}

Comments

6+6 pages, 3+4 figures