Quantum/Machines/Quandela Belenos
France · operational · Photonic
Quandela Belenos
Quandela Belenos is a photonic quantum computer operated by Quandela in France. It has 12 physical qubits. It ranks 2 of 4 photonic machines in this table by physical qubit count. 12 sourced specs are in the spec sheet. 3 published benchmark or milestone records are listed below, each marked by who measured it.
Also known as Belenos
Quandela's second-generation machine, offered through its cloud to more than 1,200 users in 30 countries at launch. Quandela said an integrated version would be delivered into a supercomputer at the end of 2025. Quandela's product page lists 1-qubit fidelity of 99.6 percent, 2-qubit fidelity of 99.0 percent and readout of 99 percent (see the benchmark table), and OVHcloud added the machine to its quantum platform in April 2026.
Spec sheet
Technical details as the builder or a paper states them, each with its own source. A blank is a fact we could not source, not a zero. Fidelity and coherence figures are in the benchmark table below.
| Spec | Value | Basis | Note | Source |
|---|---|---|---|---|
| Processor | MOSAIQ-12 QPU with a universal photonic chip, 24 optical modes | Vendor reported | Quandela's Belenos page also lists 576 QOPS and system software MosaiqOS. | quandela.comquandela.com |
| Qubit type | Single-photon qubits from semiconductor quantum dot sources | Vendor reported | Family-wide: the quantum dot description is from Quandela's technology page, not a Belenos datasheet. | quandela.comquandela.com |
| Topology | All-to-all connectivity | Vendor reported | As listed on the Belenos technical specification table. | quandela.com |
| Cooling and environment | Air-cooled | Vendor reported | Quandela lists air cooling in the Belenos spec table; no cryogenic system is mentioned. | quandela.com |
| Power draw | 8 kW | Vendor reported | Quandela lists 8 kW power consumption in the main system. | quandela.com |
| Fabrication | Foundry-produced photonic integrated circuits with in-house assembly; foundry not named | Vendor reported | Family-wide statement on Quandela's roadmap page about its QPUs, not specific to Belenos. | quandela.com |
| Software | Perceval, Qiskit, myQLM, Quandela Quantum Toolbox SDK | Vendor reported | Client programming environments listed for Belenos; the QPU system software is MosaiqOS. | quandela.com |
| Cloud platforms | Quandela cloud; OVHcloud Quantum Platform | Vendor reported | OVHcloud added Belenos in April 2026 as its second QPU; Quandela says Belenos has been in its own cloud since May 2025. | quandela.comitbrief.co.uk |
| Access and pricing | Cloud: commercial and industrial partners via Quandela cloud; pay-as-you-go billing per second on OVHcloud | Vendor reported | OVHcloud billing is per second with no commitment; neither source publishes a rate. | quandela.comitbrief.co.uk |
| Predecessor | Ascella | Vendor reported | Quandela's MosaiQ page lists Ascella, Belenos, Canopus as successive MosaiQ generations; Altair (10 qubits) and Lucy (id lucy) are also listed on the QPU page. | quandela.comquandela.com |
| Successor | Quandela Canopus | Vendor reported | Quandela said in May 2025 that Canopus would double the qubit count within a year. | thequantuminsider.comquandela.com |
| Roadmap | More than 40 qubits within three years; fault-tolerant systems from 2028 onward | Vendor reported | Stated in Quandela's 22 May 2025 launch release; the roadmap page (updated Oct 2024) targets large-scale fault-tolerant systems by 2028 and beyond. | thequantuminsider.comquandela.com |
Published benchmark figures
These are numbers the builder or a paper reports for this machine, not results from a common test. The basis column says who measured them. What the metrics mean and why they are not comparable across technologies.
| Metric | Value | Measured | Basis | Note | Source |
|---|---|---|---|---|---|
| Readout fidelity | 99% | 2026-10 | Vendor reported | Quandela product page: 99 percent; vendor-listed, no measurement date given | quandela.com |
| Single-qubit gate fidelity | 99.6% | 2026-10 | Vendor reported | Quandela product page: 99.6 +/- 0.1 percent; vendor-listed, no measurement date given | quandela.com |
| Two-qubit gate fidelity | 99% | 2026-10 | Vendor reported | Quandela product page: 99.0 +/- 0.8 percent; vendor-listed, no measurement date given | quandela.com |
Timeline
- 2025-05-22: Announced
- 2025-05: First operational
- 2026-10-07: Status checked: operational
More from Quandela
- Quandela Canopus (planned)
Comparable photonic machines
Closest in physical qubit count within the same technology. Counts of different qubit types are not interchangeable across technologies.
| Machine | Operator | Qubits | Status |
|---|---|---|---|
| Lucy | CEA | 12 | operational |
| Xanadu Aurora | Xanadu | 12 | operational |
| Xanadu Borealis | Xanadu | 216 | decommissioned |