Radio frequency reflectometry in silicon-based quantum dots

TL;DR

This paper demonstrates improved radio frequency reflectometry techniques for silicon quantum dots, overcoming parasitic capacitance challenges to achieve high-fidelity charge readout in quantum computing applications.

Contribution

It introduces two methods for mitigating parasitic capacitance effects in RF reflectometry for silicon quantum dots, enhancing measurement speed and accuracy.

Findings

Achieved 99.9% fidelity in charge readout

Demonstrated methods for parasitic capacitance mitigation

Enabled high-performance RF reflectometry in silicon quantum dots

Abstract

RF reflectometry offers a fast and sensitive method for charge sensing and spin readout in gated quantum dots. We focus in this work on the implementation of RF readout in accumulation-mode gate-defined quantum dots, where the large parasitic capacitance poses a challenge. We describe and test two methods for mitigating the effect of the parasitic capacitance, one by on-chip modifications and a second by off-chip changes. We demonstrate that these methods enable high-performance charge readout in Si/SiGe quantum dots, achieving a fidelity of 99.9% for a measurement time of 1 $\mu$s.