Google says Willow chip reduces magic state errors by approximately 40x.

In a paper published in Science, the Google Quantum AI team unveiled "magic state cultivation," a breakthrough technology implemented on their Willow processor. This method achieved approximately a 40-fold reduction in error rates and generated T states with logical fidelities reaching 99.99%. Magic states are consumable resources essential for running useful quantum programs; once utilized, they are depleted. Estimates cited by Google indicate that the cost of producing magic states could account for up to 95% of a quantum computer's total capacity, severely constraining the resources available for actual computation. Previously, the industry standard was magic state distillation, proposed by physicists Sergei Bravyi and Alexei Kitaev in 2004, which relied on massive factories of dedicated qubits specifically tasked with this process.