Riverlane and Rigetti Demonstrate Fast Live Error Decoding
An eight-qubit experiment reports mean decoding below one microsecond per round, with complete feedback measured separately.
Rigetti Computing
Uses microwave-controlled superconducting qubits to execute quantum circuits. Its Cepheus architecture connects smaller chiplets to form a larger processor.
United States · Research reviewed 7 Sept 2026Initial record: initial assessment recorded.
Review history 1 record
Record dates show when an assessment or clarification was saved. Review dates show the evidence check. Earlier records were recovered from QubitWire’s source history; no earlier score movement is inferred.
Initial assessment recorded
Assessment reviewed 7 Sept 2026 · Research reviewed 7 Sept 2026
What it does. Where it fits.
Superconducting gate-model chiplets
Who should look closer
Developers testing quantum circuits, researchers studying hardware noise and teams evaluating modular superconducting systems.
QubitWire’s editorial assessment of practical fit.Cloud access
Cepheus-1-108Q is offered through Rigetti QCS and Amazon Braket. Check the live device properties and current access terms before designing an experiment.
Check the current access route ↗What has been demonstrated
Rigetti launched the 108-qubit system in April 2026. External researchers subsequently measured state transfer across selected routes, finding that favorable paths and uniform reliability are different properties.
What remains unresolved
Physical qubit count and launch gate fidelity do not establish useful circuit depth or fault tolerance. An August 2026 external preprint finds substantial route-dependent performance; its results are specific to the tested conditions.
The next question to watch
Can improved calibration and chip-to-chip performance increase reliable circuit depth across the processor, beyond selected high-performing paths?
A research question, not a promised milestone.QubitWire coverage
Sources & evidence
- Rigetti Announces General Availability of 108-Qubit System ↗Organization-originated source · 7 Apr 2026
Released Cepheus-1-108Q on QCS and Amazon Braket on April 7, 2026. The launch report states 99.1% median two-qubit gate fidelity; its 99.5% target is prospective.
- Amazon Braket launches Rigetti Cepheus-1-108Q superconducting device ↗Organization-originated source · 1 Jun 2026
AWS and Rigetti document a twelve-chiplet processor, on-demand access, reservations, current calibration queries and Braket SDK, CUDA-Q, PennyLane and Qiskit workflows.
- How Far Can You Do Nothing On a Quantum Computer? ↗External source (may be a collaborator) · 22 Aug 2026
External researchers report route-dependent state-transfer tests on Cepheus-1-108Q. Results depend on the chosen paths, calibration snapshot and finite-shot success rule; this is a preprint.
- The Lifecycle of a Program ↗Organization-originated source · Publication date not stated
Documents Quil submission, pyQuil and supported QIR, QASM2 and Cirq transpilation pathways.
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