B Grade B
Rigetti Computing Cepheus-1-108Q: Two-qubit gate fidelity
98.82% %
As stated in the source: “Two-qubit gates, CZ (median fidelity, per op.): 98.82%”
Caveats
Live figure with no measurement date or method; page read on 27 Oct 2026 and may change. Lower than the 99.1% median Rigetti cited at general availability (April 2026), which was not read on a Rigetti page.
- Set-up
- Median CZ fidelity per operation across the device, from Rigetti's live 'Rigetti Right Now' panel (deployed 04.07.26; 107 qubits; median single-qubit fidelity 99.85%; median T1 29 and T2 11, units shown as microseconds in header).
- Method
- Standard
- Compared only with
- results in the group “median”
- Measured
- Not stated
- Published
- Not stated
- Measured by
- Rigetti Computing
- Independent of the maker
- No
- Peer-reviewed
- No
- Repeated by others
- Not yet
Source
Rigetti Computing home page, 'Rigetti Right Now' specification panel, Rigetti Computing. Company technical document.
Comparable results
| Machine | Value | Set-up | Published | Measured by | Grade | Record |
|---|---|---|---|---|---|---|
| IQM Quantum Computers Emerald | 99.5% | median | 5 Aug 2025 | Maker | C | r-000047 |
| Rigetti Computing Ankaa-3 | 99.5% | median | 23 Dec 2024 | Maker | C | r-000040 |
| IonQ Forte | 99.536% | median | 7 Nov 2024 | Maker | B | r-000030 |
| IQM Quantum Computers Garnet | 99.5% | median | 22 Aug 2024 | Maker | B | r-000044 |
History
- 27 October 2026: added
Spotted a mistake? Report an error, quoting r-000041.