Identifying the pairing mechanism in Fe-As based superconductors: gaps and isotope effects

TL;DR

This paper investigates the pairing mechanism in Fe-As superconductors by analyzing gap temperature dependencies, predicting isotope effects, and comparing these predictions with experimental data to understand the role of phonons or polarons.

Contribution

It introduces a universal temperature scaling for coupled s-wave gaps and predicts isotope effects, providing insights into the pairing mechanism in Fe-As superconductors.

Findings

Universal temperature scaling observed for coupled s-wave gaps

Predicted isotope effects if phonons or polarons are involved

Comparison with experimental data supports the proposed mechanisms

Abstract

The temperature dependencies of the coupled superconducting gaps, observed in Fe-As based superconducting compounds is calculated and a universal temperature scaling observed which is only present if the coupled order parameters both have s-wave symmetry. Predictions for possible isotope effects on the transition temperature are made if phonons are involved in the pairing or polaronic effects are of importance. Comparison to experimental data is given where these are available.