Radio frequency charge sensing in InAs nanowire double quantum dots

TL;DR

This paper demonstrates radio frequency charge sensing in InAs nanowire double quantum dots, enabling charge detection in regimes where direct current measurement is challenging, with high sensitivity and fast detection times.

Contribution

The work introduces rf-reflectometry for charge sensing in InAs nanowire DQDs, allowing charge detection in the few-electron regime with improved speed and sensitivity.

Findings

Successful charge sensing via rf-reflectometry in InAs nanowire DQDs.

Achieved minimum charge detection times of 350 microseconds and 9 microseconds.

Observed clear single dot and DQD behavior in the resonator response.

Abstract

We demonstrate charge sensing of an InAs nanowire double quantum dot (DQD) coupled to a radio frequency (rf) circuit. We measure the rf signal reflected by the resonator using homodyne detection. Clear single dot and DQD behavior are observed in the resonator response. rf-reflectometry allows measurements of the DQD charge stability diagram in the few-electron regime even when the dc current through the device is too small to be measured. For a signal-to-noise ratio of one, we estimate a minimum charge detection time of 350 microseconds at interdot charge transitions and 9 microseconds for charge transitions with the leads.