Multiphase Superconductivity in Skutterudite PrOs_4Sb_12

TL;DR

This paper presents a model for the nodal order parameters in the superconducting phases of PrOs_4Sb_12, explaining experimental thermal conductivity data and highlighting the effects of impurities on the hybrid gap structure.

Contribution

The paper introduces a hybrid s- and g-wave gap model for PrOs_4Sb_12 that aligns with experimental thermal conductivity observations and explores impurity effects on the superconducting gap.

Findings

The hybrid gap model explains angular-dependent thermal conductivity data.

Impurity scattering induces a gap opening, leading to exponential low-temperature behavior.

The model accounts for the distinct properties of the A and B superconducting phases.

Abstract

We propose a model of nodal order parameters for the superconducting A and B - phase of skutterudite PrOs_4Sb_{12} and discuss the associated angular dependent magnetothermal conductivity at low temperatures. The model for the hybrid gap functions \De(k) containing an s- and g- wave parts is consistent with recent thermal conductivity experiments in PrOs_4Sb_12. In particular the model accounts for the data on polar an azimuthal field angle dependence of \kappa_zz(\theta,\phi). The low temperature behaviour of thermodynamic properties in zero field is also presented. We show that the effect of impurity scattering on a nodal hybrid gap function immediately leads the opening of a gap and related exponential behaviour of low temperature specific heat and thermal conductivity which is very different from d- wave superconductors.