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arXiv · 2101.11864

Single-shot readout of a driven hybrid qubit in a GaAs double quantum dot

Wonjin Jang·Min-Kyun Cho·Hyeongyu Jang·Jehyun Kim·Jaemin Park·Gyeonghun Kim·Byoungwoo Kang·Hwanchul Jung·Vladimir Umansky·Dohun Kim
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Abstract

We report a single-shot-based projective readout of a semiconductor hybrid qubit formed by three electrons in a GaAs double quantum dot. Voltage-controlled adiabatic transitions between the qubit operations and readout conditions allow high-fidelity mapping of quantum states. We show that a large ratio both in relaxation time vs. tunneling time (~ 50) and singlet-triplet splitting vs. thermal energy (~ 20) allow energy-selective tunneling-based spin-to-charge conversion with readout visibility ~ 92.6%. Combined with ac driving, we demonstrate high visibility coherent Rabi and Ramsey oscillations of a hybrid qubit in GaAs. Further, we discuss the generality of the method for use in other materials, including silicon.

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Wonjin Jang, Min-Kyun Cho, Hyeongyu Jang, Jehyun Kim, Jaemin Park, Gyeonghun Kim, Byoungwoo Kang, Hwanchul Jung, Vladimir Umansky, Dohun Kim. 2021-01-28. Single-shot readout of a driven hybrid qubit in a GaAs double quantum dot. https://doi.org/10.1021/acs.nanolett.1c00783

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