Temperature-dependent spin resonance energy in iron pnictides and multiband s\pm Eliashberg theory

TL;DR

This paper models the temperature-dependent spin resonance energy in iron pnictide superconductors using a three-band s extbackslash extpm wave Eliashberg theory, successfully fitting experimental data with minimal parameters.

Contribution

It introduces a multiband Eliashberg framework incorporating feedback effects to accurately describe superconductivity in iron pnictides.

Findings

Reproduces critical temperatures and gaps for four iron pnictide materials.

Achieves good agreement with experimental data in a moderate strong-coupling regime.

Demonstrates the importance of feedback effects in modeling superconductivity.

Abstract

The phenomenology of iron-pnictides superconductors can be explained in the framework of a three bands s\pm wave Eliashberg theory with only two free parameters plus a feedback effect i.e. the effect of the condensate on the antiferromagnetic spin fluctuactions responsible of the superconductivity in these compounds. I have examined the experimental data of four materials: LaFeAsO1-xFx, SmFeAsO1-xFx, Ba1-xKxFe2As2, and Ba(FexCo1-x)2As2 and I have found that it is possible to reproduce the experimental critical temperature and gap values in a moderate strong-coupling regime: ltot about 1.7-2.0.