Quantum control of solid-state spin qubits typically involves pulses in the microwave domain, drawing from the well-developed toolbox of magnetic resonance spectroscopy. Driving a solid-state spin by optical means offers a high-speed alternative, which in the presence of limited spin coherence makes it the preferred approach for high-fidelity quantum control. Bringing the full versatility of magnetic spin resonance to the optical domain requires full phase and amplitude control of the optical fields. Here, we imprint a programmable microwave sequence onto a laser field and perform electron spin resonance in a semiconductor quantum dot via a two-photon Raman process. We show that this approach yields full SU(2) spin control with over 98% pi-rotation fidelity. We then demonstrate its versatility by implementing a particular multi-axis control sequence, known as spin locking. Combined with electron-nuclear Hartmann-Hahn resonances which we also report in this work, this sequence will enable efficient coherent transfer of a quantum state from the electron spin to the mesoscopic nuclear ensemble.
@article{arxiv.1906.00427,
title = {Optical spin locking of a solid-state qubit},
author = {J. H. Bodey and R. Stockill and E. V. Denning and D. A. Gangloff and G. Ethier-Majcher and D. M. Jackson and E. Clarke and M. Hugues and C. Le Gall and M. Atature},
journal= {arXiv preprint arXiv:1906.00427},
year = {2020}
}