A study published Oct. 15 reported that Google Quantum AI’s Willow processor prepared logical T-states with 99.99% fidelity, a measure of state preparation rather than whole-computer performance.
The study recorded a 40-fold reduction in errors, while only 8% of attempts were retained. The fidelity result applies to the prepared states; it does not describe the performance of every operation on a complete quantum computer.
The experiment also placed cultivated states first in a distance-3 color code and later in a distance-5 surface code. The paper identifies grafting the states into larger code distances as a future direction.
