Possible phase-sensitive tests of pairing symmetry in pnictide superconductors

TL;DR

This paper proposes phase-sensitive Josephson interferometry experiments to determine the pairing symmetry in pnictide superconductors, addressing ongoing debates about whether they exhibit s-wave, d-wave, or other exotic order parameters.

Contribution

It introduces specific experimental designs for phase-sensitive tests to clarify the pairing symmetry in pnictide superconductors, extending previous methods used for cuprates.

Findings

Proposed multiple Josephson interferometry experiments.

Potential to distinguish between s-wave and d-wave symmetries.

Addresses controversy over pairing symmetry in pnictides.

Abstract

The discovery of the new class of pnictide superconductors has engendered a controversy about their pairing symmetry, with proposals ranging from an extended s-wave or "s$_{\pm}$" symmetry to nodal or nodeless d-wave symmetry to still more exotic order parameters such as p-wave. In this paper, building on the earlier, similar work performed for the cuprates, we propose several phase-sensitive Josephson interferometry experiments, each of which may allow resolution of the issue.