Measurement of the current-phase relation of superconducting atomic contacts

TL;DR

This paper measures the current-phase relation of superconducting atomic contacts within a superconducting loop, confirming theoretical models with experimental data.

Contribution

It provides the first quantitative experimental validation of the current-phase relation in atomic contacts using independently measured conduction channels.

Findings

Measurements agree with resistively shunted SQUID model

Current-phase relation matches theoretical predictions

Demonstrates precise control and understanding of atomic-scale superconducting contacts

Abstract

We have probed the current-phase relation of an atomic contact placed with a tunnel junction in a small superconducting loop. The measurements are in quantitative agreement with the predictions of a resistively shunted SQUID model in which the Josephson coupling of the contact is calculated using the independently determined transmissions of its conduction channels.