Catalog — QPU record · Rigetti · Superconducting
Cepheus-1-108Q
Cepheus-1-108Q is a superconducting gate-based processor by Rigetti with 108 qubits (2026). Below: every publicly disclosed figure with its source, method, and vendor-claim status — plus what is not disclosed, recorded as findings.
Measurement records9 disclosed · 1 not disclosed · 3 sources
Select a figure to open its record
Qubit count (qubit_count_physical)108 qubitsvendor claim
Vendor claim
- Source
- Rigetti GA press release 'Rigetti Announces General Availability of 108-Qubit System' and rigetti.com/what-we-build ('Qubits 108') · published 2026-04-07
- Method
- VENDOR_UNSPECIFIED
- Notes
- Twelve 9-qubit chiplets, tripling qubits and chiplets vs Cepheus-1-36Q.
- Citation key
[rigetti/cepheus-1-108q:qubit-count-physical:2026-08-19]
Two-qubit gate quality (two_qubit_gate_fidelity)99.1 %vendor claim
Vendor claim
- Source
- Rigetti GA press release (2026-04-07) and rigetti.com/what-we-build spec table (fetched 2026-08-19 session) · published 2026-04-07
- Method
- not stated ('currently performing at a 99.1% median two-qubit gate fidelity'); gate type CZ per what-we-build table 'Two-qubit gates (CZ) 99.1%'
- Aggregation
- median
- Notes
- Earlier (Jan 9, 2026 PR): 'median two-qubit gate fidelity of 99% on our 108-qubit system' pre-GA. Vendor expects the system to 'reach a median 99.5% two-qubit gate fidelity later this year' (2026) — target, not a measurement.
- Citation key
[rigetti/cepheus-1-108q:two-qubit-gate-fidelity:2026-08-19]
Two-qubit gate quality (two_qubit_gate_fidelity_best_prototype)99.9 (at 28 ns gate duration) %vendor claim
Vendor claim
- Source
- Rigetti GA press release: 'Rigetti achieved a two-qubit gate fidelity as high as 99.9% at 28 nanoseconds on a prototype system using a proprietary implementation of an adiabatic CZ gate scheme. These gates are already in use on Cepheus-1-108Q' · published 2026-04-07
- Method
- proprietary implementation of an adiabatic CZ gate scheme; benchmarking method not stated
- Aggregation
- best ('as high as'), measured on a prototype system, not the deployed 108Q device
- Notes
- Recorded separately from the deployed-system median because it is a best-case prototype figure.
- Citation key
[rigetti/cepheus-1-108q:two-qubit-gate-fidelity-:2026-08-19]
Single-qubit gate quality (one_qubit_gate_fidelity)99.9 %vendor claim
Vendor claim
- Source
- Rigetti GA press release and rigetti.com/what-we-build · published 2026-04-07
- Method
- VENDOR_UNSPECIFIED
- Aggregation
- median ('a 99.9% median single-gate fidelity'; what-we-build: 'Median Fidelity (per op.) — Single-qubit gates 99.9%')
- Citation key
[rigetti/cepheus-1-108q:one-qubit-gate-fidelity:2026-08-19]
Gate duration (two_qubit_gate_duration)~60 nsvendor claim
Vendor claim
- Source
- Rigetti GA press release · published 2026-04-07
- Method
- VENDOR_UNSPECIFIED
- Aggregation
- not stated ('a gate speed of ~60 ns')
- Notes
- Company-level claim in same PR: 'Current Rigetti quantum computing systems achieve gate speeds of 50-70ns.'
- Citation key
[rigetti/cepheus-1-108q:two-qubit-gate-duration:2026-08-19]
Coherence (T1)25 µsvendor claim
Vendor claim
- Method
- VENDOR_UNSPECIFIED
- Aggregation
- median ('Median Time Duration (µs)')
- Notes
- PR notes coherence time is now 'the primary performance limitation' after coupler-interaction mitigation beyond 100 qubits.
- Citation key
[rigetti/cepheus-1-108q:t1:2026-08-19]
Coherence (T2)10 µsvendor claim
Vendor claim
- Method
- VENDOR_UNSPECIFIED
- Aggregation
- median ('Median Time Duration (µs)')
- Citation key
[rigetti/cepheus-1-108q:t2:2026-08-19]
Readout (readout_fidelity)not publicly disclosed
Not publicly disclosed — checked 2026-08-19
- Finding
- No public disclosure found. This is a recorded, dated finding — we do not substitute an estimate or borrow a figure from a sibling device.
- Sources queried
- GA press release (fetched in full), Jan 2026 update PR, rigetti.com/what-we-build, AWS Braket developer guide and Rigetti device page, Azure Quantum Rigetti provider page
- Notes
- GA PR mentions 'a newly engineered control system delivers superior signal-to-noise ratio for qubit readout' but gives no figure. Braket console calibration data requires login; qcs.rigetti.com/qpus is a JavaScript SPA with no static content.
Announced and ga dates (announced_and_ga_dates)GA 2026-04-07 (what-we-build: 'deployed on April 7, 2026'); previously announced in roadmap as 100+ qubit system for end-2025 (Dec 2024 PR), delayed per Jan 9, 2026 PR to ~end of Q1 2026vendor claim
Vendor claim
- Source
- Rigetti GA press release (2026-04-07); 'Rigetti Computing Provides Update on 108-Qubit System' (2026-01-09) · published 2026-04-07
- Method
- VENDOR_UNSPECIFIED
- Citation key
[rigetti/cepheus-1-108q:announced-and-ga-dates:2026-08-19]
Pricing model (pricing_model_exists)yes — Amazon Braket: $0.30 per task + $0.000425 per shot (row 'Rigetti | Cepheus'), reservation mode $4,100/hour; Azure Quantum has a Rigetti billing plan (Azure Quantum pricing page referenced from provider doc)vendor claim
Vendor claim
- Method
- VENDOR_UNSPECIFIED
- Citation key
[rigetti/cepheus-1-108q:pricing-model-exists:2026-08-19]
QPU137 is independent and is not affiliated with, endorsed by, or sponsored by Rigetti. Figures above are public disclosures recorded with their sources on 2026-08-19; vendor claims are labeled as such and may not be directly comparable across measurement methods — see methodology.