Impurity effects on electronic transport in ferropnictide superconductors

TL;DR

This paper theoretically investigates how impurities affect electronic transport in iron pnictide superconductors, revealing threshold effects in conductivity and thermoelectric properties at high impurity concentrations.

Contribution

It introduces a new theoretical framework for understanding impurity-induced narrow bands within the superconducting gap in iron pnictides.

Findings

Impurities induce narrow conducting quasiparticle bands within the superconducting gap.

Threshold effects are predicted in optical and thermal conductivities at high impurity levels.

Potential applications in thermoelectric devices are suggested.

Abstract

Effects of impurities and disorder on transport properties by electronic quasiparticles in superconducting iron pnictides are theoretically considered. The most prominent new features compared to the case of pure material should appear at high enough impurity concentration when a specific narrow band of conducting quasiparticle states can develop within the superconducting gap, around the position of localized impurity level by a single impurity center. The predicted specific threshold effects in the frequency dependent optical conductivity and temperature dependent thermal conductivity and also in Seebeck and Peltier coefficients can have interesting potentialities for practical applications.