Google Cuts Errors in Quantum 'Magic States' About 40-Fold on Its Willow Processor

Google researchers say they have reduced errors in a crucial quantum computing resource about 40-fold, a step that could lower the hardware demands of useful, error-corrected machines.

The experiment, published in Science, showed that a technique called magic-state cultivation works on Google's Willow processor, according to a Google Quantum AI blog post. The company reported producing states known as T-states with a logical fidelity of 99.99%, a measure of how closely a protected quantum state matches its intended form.

The result addresses a problem in quantum computing: preparing these states could consume much of a future machine's resources and leave less capacity for the calculations it is meant to perform. Google's demonstration moves a proposed way to reduce that burden from theory to hardware.

Caveats

The researchers also transferred prepared states between two forms of quantum error correction, an early test of whether the method can connect with the architecture intended to support larger computations. Google acknowledged that the work does not necessarily show the resource problem is solved at a practical scale; larger demonstrations are still needed, and a storage test produced errors about seven times higher than simulations predicted.