Alice & Bob
Superconducting quantum-computing hardware built on cat qubits — bosonic qubits encoded in a microwave cavity that autonomously suppress bit-flip errors, leaving mainly phase-flips for an outer error-correction code to handle. Founded in 2020 by two QUANTIC-trained physicists and headquartered in Paris with a Boston office, the company spun out of work with Mines Paris–PSL, ENS, and Inria. It targets fault-tolerant machines with fewer physical qubits per logical qubit than uncorrected-transmon approaches, and offers cat-qubit chips through Google Cloud to early-access researchers and enterprises tracking the fault-tolerant roadmap.
Timeline
Current flagship
Boson cat-qubit chips — superconducting cat qubit (Boson series; accessible via Google Cloud)
Milestones
- 2026-05NVentures (NVIDIA) joins Series B as an extension investor
- 2025-09Preliminary cat-qubit bit-flip lifetime measured beyond one hour, surpassing the prior ~430 s record
- 2025-01€100M Series B closed
- 2024-12Roadmap published — five chip generations (Boson, Helium, Lithium, Beryllium, Graphene) to 100 logical qubits by 2030
- 2024-05Cat qubit with bit-flip times exceeding ten seconds published in Nature (Boson 3 / TomCat design)
Roadmap
- 2030 100 high-fidelity logical qubits (Graphene chip series) targeting quantum advantage in early industrial use cases source ↗
- 2030 Logical-qubit fidelity target of 99.9999% ("six nines") per the published roadmap source ↗
- 2024 Milestone 1 — Master the Cat Qubit (Boson series); reported achieved per the 2024 roadmap source ↗
- 2025 Milestone 2 — first below-threshold error-corrected logical qubit (Helium chip series) source ↗
Capability details
Quantum computing
- Qubit type
- cat
- Physical qubits
- —
- Logical qubits
- 0
- 1Q gate fidelity
- —
- 2Q gate fidelity
- —
- T₁
- —
- T₂
- —
- EC code
- repetition
- Connectivity
10 unverified fields
-
modalities.qc.physical_qubits_current -
modalities.qc.one_q_fidelity -
modalities.qc.two_q_fidelity -
modalities.qc.coherence_t1_ms -
modalities.qc.coherence_t2_ms -
modalities.qc.connectivity -
modalities.qc.gate_set -
milestones.1.headline— The "beyond one hour" bit-flip lifetime is from a September 2025 vendor announcement of preliminary results; peer-reviewed citation pending. The peer-reviewed lifetime figure of record remains the Nature 2024 ten-seconds result. -
roadmap— Logical-qubit counts, the six-nines fidelity target, and the 2030 date are forward targets stated in the December 2024 roadmap white paper; peer-reviewed validation of the logical-qubit milestones pending as each chip generation ships. -
shareholders— Private company; no equity percentages disclosed. Holders and lead/strategic roles are taken from Series B and Series B-extension press releases. FFC is the round lead; no single controlling holder is disclosed.
People
References
- paper https://www.nature.com/articles/s41586-024-07294-3 "Quantum control of a cat-qubit with bit-flip times exceeding ten seconds," Nature, May 2024 — peer-reviewed bit-flip-lifetime result on the Boson 3 chip (TomCat design), with the QUANTIC team (Mines Paris–PSL, ENS, Inria).
- press https://alice-bob.com/newsroom/alice-bob-surpasses-bit-flip-stability-record/ September 2025 announcement of preliminary bit-flip lifetime beyond one hour; peer-reviewed publication of this result pending.
- press https://alice-bob.com/wp-content/uploads/2024/12/Alice-Bob-Roadmap-Long-Version.pdf Long-form 2030 roadmap white paper (five chip generations, 100 logical qubits).
- press https://alice-bob.com/newsroom/alice-bob-100m-series-b-fundraising-press-release/ Series B closing press release (investor list, use of funds).