Google Demonstrates Magic State Cultivation On Willow Quantum Processor
Magic states are the resource that lets a corrected quantum computer run operations beyond error correction alone, and a method that cuts their error rate by roughly 40 times with 99.99% fidelity on existing hardware attacks the step that has been consuming the largest share of processing capacity.
Reporting from 1 source: GIGAZINE.
Google Quantum AI reported that it carried out magic state cultivation on the Willow quantum processor and reduced the probability of error to about 1/40 of the uncultivated case. Fidelity, the measure of how close the produced state is to the ideal target, reached about 99.99%. The method prepares an imperfect magic state and discards trials where measurement detects a problem.
The method comes from a 2024 proposal by Craig Gidney and colleagues at Google Quantum AI. Instead of trying to build a perfect magic state from the start, it prepares a magic state containing errors in a small region of the processor, then examines it through measurements on multiple qubits. Trials where an error is detected are discarded, and only clean results are kept.
Generating high-quality magic states is expensive: as much as 95% of a quantum computer's processing capacity may go to producing them, and because they are consumed during use, they have to be regenerated as calculations proceed.
Synthesized by Yomimono from the 1 cited source below, including Japanese-language reporting where cited, then editorially reviewed before publishing.