Preserving qubit coherence and maintaining high-fidelity qubit control under complex noise environment is an enduring challenge for scalable quantum computing. Here we demonstrate an addressable fault-tolerant single spin qubit with an average control fidelity of 99.12% via randomized benchmarking on a silicon quantum dot device with an integrated micromagnet. Its dephasing time T2* is 1.025 us and can be enlarged to 264 us by using the Hahn echo technique, reflecting strong low-frequency noise in our system. To break through the noise limitation, we introduce geometric quantum computing to obtain high control fidelity by exploiting its noise-resilient feature. However, the control fidelities of the geometric quantum gates are lower than 99%. According to our simulation, the noise-resilient feature of geometric quantum gates is masked by the heating effect. With further optimization to alleviate the heating effect, geometric quantum computing can be a potential approach to reproducibly achieving high-fidelity qubit control in a complex noise environment.
@article{arxiv.2310.06569,
title = {Single spin qubit geometric gate in a silicon quantum dot},
author = {Rong-Long Ma and Ao-Ran Li and Chu Wang and Zhen-Zhen Kong and Wei-Zhu Liao and Ming Ni and Sheng-Kai Zhu and Ning Chu and Cheng-Xian Zhang and Di Liu and Gang Cao and Gui-Lei Wang and Hai-Ou Li and Guo-Ping Guo},
journal= {arXiv preprint arXiv:2310.06569},
year = {2024}
}