A >99.9%-fidelity quantum-dot spin qubit with coherence limited by charge noise

Understand

Recent advances towards spin-based quantum computation have been primarily fuelled by elaborate isolation from noise sources, such as surrounding nuclear spins and spin-electric susceptibility, to extend spin coherence.

• In the meanwhile, addressable single-spin and spin-spin manipulations in multiple-qubit systems will necessitate sizable spin-electric coupling.
• Given background charge fluctuation in nanostructures, however, its compatibility with enhanced coherence should be crucially questioned.
• Here we realise a single-electron spin qubit with isotopically-enriched phase coherence time (20 microseconds) and fast electrical control speed (up to 30 MHz) mediated by extrinsic spin-electric coupling.