Google's Willow chip cuts magic-state errors 40-fold but rejects 92% of attempts

Google demonstrated magic-state cultivation on its 105-qubit Willow processor, reducing error rates of accepted states roughly 40-fold. The technique discarded about 92% of attempts, and accuracy remains far from the 1-in-a-million target needed for molecular simulation.

• Experiment used 54 of Willow's 105 physical qubits
• Error rate of accepted magic states dropped about 40-fold
• Roughly 92% of attempts were rejected, hurting efficiency
• Current accuracy ~1 in 10,000 vs target of 1 in a million