Feedback-tuned noise-resilient gates for encoded spin qubits

Understand

Two level quantum mechanical systems like spin 1/2 particles lend themselves as a natural qubit implementation.

• However, encoding a single qubit in several spins reduces the resources necessary for qubit control and can protect from decoherence channels.
• While several varieties of such encoded spin qubits have been implemented, accurate control remains challenging, and leakage out of the subspace of valid qubit states is a potential issue.
• Here, we realize high-fidelity single qubit operations for a qubit encoded in two electron spins in GaAs quantum dots by iterative tuning of the all-electrical control pulses.