Comparing tunneling spectroscopy and charge sensing of Andreev bound states in a semiconductor-superconductor hybrid nanowire structure

TL;DR

This paper compares traditional transport spectroscopy and non-invasive charge sensing methods for studying Andreev bound states in hybrid nanowires, demonstrating charge sensing's accuracy and simplicity.

Contribution

It introduces and validates a charge sensing approach as an effective alternative to transport measurements for ABS spectroscopy in hybrid nanostructures.

Findings

Charge sensing provides accurate ABS measurements.

Charge sensing avoids complexities of transport measurements.

Methods are consistent and complementary.

Abstract

Transport studies of Andreev bound states (ABSs) are complicated by the interplay of charging effects and superconductivity. Here, we compare transport approaches to ABS spectroscopy in a semiconductor-superconductor island to a charge-sensing approach based on an integrated radio-frequency single-electron transistor. Consistency of the methods demonstrates that fast, non-invasive charge sensing allows accurate quantitative measurement of ABSs while eluding some complexities of transport.