Josephson effect in $CeCoIn_5$ microbridges as seen via quantum interferometry

TL;DR

This study demonstrates the Josephson effect in $CeCoIn_5$ microbridges using a SQUID, revealing vortex dynamics and phase-sensitive measurement potential for understanding the superconductor's order parameter.

Contribution

First observation of Josephson effects in $CeCoIn_5$ microbridges via quantum interferometry, linking vortex behavior to superconducting properties and phase-sensitive analysis.

Findings

Good quality SQUID voltage oscillations observed

Temperature dependence matches Ambegaokar-Baratoff relation

Vortex motion influences transport characteristics

Abstract

A superconducting quantum interference device (SQUID) was prepared on a micron-sized single crystal using a selected growth domain of a thin film of $CeCoIn_5$ grown by molecular beam epitaxy. SQUID voltage oscillations of good quality were obtained as well as interference effects stemming from the individual Josephson microbridges. The transport characteristics in the superconducting state exhibited several peculiarities which we ascribe to the periodic motion of vortices in the microbridges. The temperature dependence of the Josephson critical current shows good correspondence to the Ambegaokar-Baratoff relation, expected for the ideal Josephson junction. The results indicate a promising pathway to identify the type of order parameter in $CeCoIn_5$ by means of phase-sensitive measurements on microbridges.