Superconducting proximity effect and long-ranged triplets in dirty metallic antiferromagnets

TL;DR

This paper explains how impurities in dirty metallic antiferromagnets induce magnetic effects that suppress superconductivity and generate both short- and long-ranged triplet correlations, clarifying their role in proximity effects.

Contribution

It demonstrates that impurities in antiferromagnets create effective magnetic components, leading to superconductivity suppression and the emergence of long-range triplet correlations, a novel insight into antiferromagnetic proximity effects.

Findings

Impurities induce an effective magnetic component in antiferromagnets.

Superconductivity suppression is linked to impurity effects.

Long-range triplet correlations are generated in dirty antiferromagnets.

Abstract

Antiferromagnets have no net spin-splitting on the scale of the superconducting coherence length. Despite this, antiferromagnets have been observed to suppress superconductivity in a similar way as ferromagnets, a phenomenon that still lacks a clear understanding. We find that this effect can be explained by the role of impurities in antiferromagnets. Using quasiclassical Green's functions, we study the proximity effect and critical temperature in diffusive superconductor-metallic antiferromagnet bilayers. The non-magnetic impurities acquire an effective magnetic component in the antiferromagnet. This not only reduces the critical temperature but also separates the superconducting correlations into short-ranged and long-ranged components, similar to ferromagnetic proximity systems.