Joule spectroscopy of hybrid superconductor-semiconductor nanodevices

TL;DR

This paper introduces Joule spectroscopy as a novel method to characterize hybrid superconductor-semiconductor nanodevices, revealing detailed device properties and emphasizing the role of heating effects often overlooked in such systems.

Contribution

The study demonstrates that Joule heating measurements can serve as a powerful spectroscopic tool to analyze hybrid superconductor-semiconductor devices, providing detailed insights into their microscopic properties.

Findings

Identified differences in superconducting coherence lengths of leads.

Revealed inhomogeneous shell coverage and inverse proximity effects.

Highlighted the significance of heating effects in device behavior.

Abstract

Hybrid superconductor-semiconductor devices offer highly tunable platforms, potentially suitable for quantum technology applications, that have been intensively studied in the past decade. Here we establish that measurements of the superconductor-to-normal transition originating from Joule heating provide a powerful spectroscopical tool to characterize such hybrid devices. Concretely, we apply this technique to junctions in full-shell Al-InAs nanowires in the Little-Parks regime and obtain detailed information of each lead independently and in a single measurement, including differences in the superconducting coherence lengths of the leads, inhomogeneous covering of the epitaxial shell, and the inverse superconducting proximity effect; all-in-all constituting a unique fingerprint of each device and highlighting the large variability present in these systems. Besides the practical uses, our work also underscores the importance of heating in hybrid devices, an effect that is often overlooked.