Magic state cultivation is a method for preparing high-fidelity “magic” (T) states that fault-tolerant quantum computers need for universal computation. Instead of relying only on expensive distillation, a noisy state is injected into a small error-correcting region, checked with coordinated measurements that discard flawed attempts, and gradually grown into a cleaner logical state.
On October 15, 2026, Google Quantum AI reported demonstrating cultivation on its Willow superconducting processor, reducing errors about 40-fold relative to uncultivated states and reaching at least 99.99% logical fidelity while retaining about 8% of attempts. The team also showed grafting the purified state from a color code into a surface code on real hardware.
Source: Google Quantum AI, “Bringing the magic: Google breaks open a bottleneck in quantum computing” (Oct 15, 2026).