Identifying the Pairing Mechanism in Fe–As Based Superconductors: Gaps and Isotope Effects

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 superconducting transition temperature T c 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.