Impurity induced density of states and residual transport in nonunitary superconductors

TL;DR

This paper derives general formulas for residual density of states and conductivities in non-unitary superconductors, applying them to PrOs4Sb12's B phase, revealing anisotropic conductivity signatures from off-axis nodes.

Contribution

It provides the first comprehensive expressions for impurity effects in non-unitary superconductors and applies them to a specific material with symmetry-based gap functions.

Findings

Conductivity tensor exhibits anisotropy due to off-axis nodes.

Residual density of states is explicitly calculated for impurity scattering.

Results are applicable to experimental detection of non-unitary superconducting states.

Abstract

We obtain general expressions for the residual density of states, electrical conductivity and thermal conductivity for non-unitary superconductors due to impurity scattering. We apply the results to the so-called `B phase' of PrOs4Sb12, which we describe using a non-unitary gap function derived from symmetry considerations. The conductivity tensor has inequivalent diagonal components due to off-axis nodal positions which may be detectable in experiments.