Nematic spectral signatures of the Hund's metal

TL;DR

This study uses dynamical mean-field theory to connect nematic order signatures in iron-based superconductors with Hund's metal correlations, revealing spectral weight redistribution and orbital-selective coherence effects.

Contribution

It demonstrates that nematic spectral signatures are intrinsically linked to Hund's physics and cannot be explained by simple quasiparticle models.

Findings

Nematic order causes spectral weight redistribution, not energy shifts.

Nematic ordering induces orbital-selective coherence.

Results align with experimental observations.

Abstract

We show, by means of dynamical mean-field theory calculations, that the experimental fingerprints of the nematic order in iron-based superconductors are intrinsically connected with the electronic correlations in the Hund's correlated metallic state and they can not be accessed via a renormalized quasiparticle picture. In particular, our results show that: (i) in a metal in which correlations are dominated by the Hund's coupling the nematic ordering does not produce a rigid energy shift in the photoemission spectra, but a much richer spectral weight redistribution which mirrors the experimental results; (ii) the nematic ordering is characterized by an orbital-selective coherence induced by the Hund's physics in agreement with the experimental picture.