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.
@article{arxiv.2101.11864,
title = {Single-shot readout of a driven hybrid qubit in a GaAs double quantum dot},
author = {Wonjin Jang and Min-Kyun Cho and Hyeongyu Jang and Jehyun Kim and Jaemin Park and Gyeonghun Kim and Byoungwoo Kang and Hwanchul Jung and Vladimir Umansky and Dohun Kim},
journal= {arXiv preprint arXiv:2101.11864},
year = {2021}
}