B Grade B
Google Willow: Two-qubit gate fidelity
99.67% %
As stated in the source: “0.33% ± 0.18% two-qubit gate error (CZ), mean, simultaneous”
Uncertainty: 99.49 to 99.85 (converted from the stated error and its uncertainty).
Caveats
This is an error, not a fidelity (equivalent to about 99.67% mean fidelity). Recorded exactly as stated. Vendor-reported; Chip 1 and Chip 2 are different physical chips with different numbers. Converted from the stated mean CZ error of 0.33% ± 0.18%.
- Set-up
- CZ gates, mean across device, all gates operated simultaneously.
- Method
- Randomized benchmarking, reported as average error
- Compared only with
- results in the group “mean”
- Measured
- Not stated
- Published
- 9 December 2024
- Measured by
- Google Quantum AI
- Independent of the maker
- No
- Peer-reviewed
- No
- Repeated by others
- Not yet
Source
Willow Spec Sheet, Google Quantum AI. Company technical document.
Comparable results
| Machine | Value | Set-up | Published | Measured by | Grade | Record |
|---|---|---|---|---|---|---|
| Quantinuum Helios | 99.921% | mean | 17 Jun 2026 | Maker | B | r-000017 |
| Quantinuum H2 | 99.843% | mean | 2025 | Maker | B | r-000023 |
| Google Willow | 99.86% | mean | 9 Dec 2024 | Maker | B | r-000006 |
| QuEra Computing Harvard–MIT rubidium atom array | 99.54% | mean | 11 Oct 2023 | Maker | B | r-000032 |
History
- 27 October 2026: added
Spotted a mistake? Report an error, quoting r-000005.