Superconducting charge sensor coupled to an electron layer in silicon

TL;DR

This paper demonstrates a superconducting charge sensor coupled to a silicon electron layer, capable of detecting single-electron transfers with high reliability and tunability, relevant for quantum metrology and error detection.

Contribution

It introduces a flexible superconducting charge sensor integrated with silicon electron islands, enabling tunable coupling and effective error detection in electron transfer experiments.

Findings

Charge detection bandwidth of 5.87 kHz with SNR of 1 at 300 mK

Device configuration affects sensor reliability and operation modes

Sensor's tunability enhances error detection in electron pumping

Abstract

Schemes aimed at transferring individual electrons in semiconductor devices and detecting possible transfer errors have increasing importance for metrological applications. We study the coupling of a superconducting Josephson-junction-based charge detector to an electron island defined by field-effect in silicon. The flexibility of our device allows one to tune the coupling using the detector as an additional gate electrode. We study the reliability of the electron sensor in different device configurations and the suitability of various operation modes for error detection in electron pumping experiments. As a result, we obtain a charge detection bandwidth of 5.87 kHz with unity signal to noise ratio at 300 mK bath temperature.