Superconducting proximity effect in the presence of strong spin scattering

TL;DR

This study investigates how superconducting proximity effects influence resistance in gold wires with magnetic impurities, revealing persistence of proximity effects despite strong spin scattering.

Contribution

It demonstrates that superconducting proximity effects can persist in the presence of strong spin scattering due to magnetic impurities.

Findings

Resistance initially decreases below superconducting transition

Resistance increases at lower temperatures above normal state resistance

Proximity effect remains significant despite magnetic impurities

Abstract

We report measurements of the four terminal temperature dependent resistance of narrow Au wires implanted with ~100 ppm Fe impurities in proximity to superconducting Al films. The wires show an initial decrease in resistance as the temperature is lowered through the superconducting transition of the Al films, but then show an increase in resistance as the temperature is lowered further. In contrast to the case of pure Au wires in contact with a superconducting film, the resistance at the lowest temperatures rises above the normal state resistance. Analysis of the data shows that, in addition to contributions from magnetic scattering and electron-electron interactions, the temperature dependent resistivity shows a substantial contribution from the superconducting proximity effect, which exists even in the presence of strong spin scattering.