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arXiv:2408.15380 · npj Quantum Information

Single shot latched readout of a quantum dot qubit using barrier gate pulsing

Sanghyeok Park, Jared Benson, J. Corrigan, J. P. Dodson, S. N. Coppersmith, Mark G. Friesen, M. A. Eriksson

Published Sep 2, 2025• 3 citations
arXivHTMLPDF

Abstract

Qubit latching techniques require precise tuning of multiple tunnel rates, which can be challenging when a qubit is coupled to a single reservoir. Here, we present such a method for single-shot measurement, in which the barrier gate is pulsed to dynamically control qubit-to-reservoir tunnel rates. We use it to reduce the qubit reset time in measurements of coherent Larmor oscillations of a Si/SiGe quantum dot hybrid qubit. The method is also readily applicable to other types of spin-based qubits.

DOI
10.1038/s41534-025-01094-x

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Measuring electrical charge with single-electron resolution is essential for implementing spin qubits in semiconductor quantum dots. Applying quantum dot charge sensors in larger-scale quantum computing devices is being held back because these sensors are easily affected by environmental disturbances, and thus require elaborate tune-up. This study uses a feedback control circuit implemented on a field-programmable gate array to maintain sensor performance in the face of capacitive crosstalk and charge noise. The technique enables rapid tune-up of quantum dot devices and reliable single-shot electron or spin measurement, and will advance the development of large-scale spin-qubit devices.