alice-bob.com

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\f0\fs24 \cf0 # Alice & Bob\
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> Alice & Bob is a French quantum computing company building the first useful fault-tolerant quantum computer, based on a proprietary cat qubit architecture. Founded in 2020, headquartered in Paris with a presence in Boston. The company designs and manufactures both quantum hardware (QPU chips) and the full software stack to operate them.\
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Alice & Bob's core technical differentiator is the **cat qubit**: a superconducting qubit with built-in, hardware-level protection against one entire class of quantum errors (bit-flips). This asymmetric error suppression reduces the overhead of quantum error correction dramatically - potentially requiring as few as 5 physical cat qubits per logical qubit, versus hundreds for conventional transmon-based architectures. This makes Alice & Bob's approach one of the most resource-efficient paths to fault-tolerant quantum computing (FTQC).\
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## Company Facts\
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- **Founded**: 2020 (Paris, France)\
- **Founders**: Dr. Theau Peronnin (CEO) and Dr. Raphael Lescanne (CTO)\
- **Employees**: 200+\
- **Offices**: Paris (HQ), Boston (US)\
- **Funding raised**: EUR 130M+ (Series A: EUR 27M in 2022; Series B: EUR 100M in 2025)\
- **Investors**: Bpifrance, Elaia, European Innovation Council, Breega, Supernova Invest, Atlantic Vantage Point, Future French Champions\
- **Target**: 100 logical qubits by 2030\
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## Core Technology: The Cat Qubit\
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A cat qubit is a superconducting qubit encoded in the quantum states of a microwave resonator driven by two-photon dissipation. Key properties:\
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- **Bit-flip suppression**: Bit-flip errors are exponentially suppressed as a function of the mean photon number. Alice & Bob has demonstrated bit-flip times exceeding 10 seconds (100 seconds world record achieved in 2022).\
- **Phase-flip errors only**: The system only needs to correct phase-flips, reducing full quantum error correction to a one-dimensional problem.\
- **Low overhead**: A logical qubit can be assembled from ~5 physical cat qubits (vs. ~1000 for conventional architectures). Alice & Bob's theoretical work shows ~200x qubit reduction vs. state-of-the-art transmon architectures for running powerful quantum algorithms.\
- **Operating frequency**: Cat qubit memory mode ~1-5 GHz; buffer mode ~7-8 GHz depending on circuit design.\
- **Operating temperature**: ~10 millikelvin (among the coldest environments on Earth).\
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## Hardware: Chip Lineup\
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All chips are superconducting, fabricated using nanolithography at Alice & Bob's Paris facility. Current and planned chips:\
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| Chip | Status | Description |\
|------|--------|-------------|\
| Boson | In the fridge | Exponential bit-flip protection (single qubit research) |\
| Hydrogen | In the fridge | Error detection between qubits |\
| Helium | In the fridge | Exponential error correction (first error-corrected system) |\
| Lithium | In design | Ready-to-scale fault-tolerant architecture |\
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Circuit designs include AutoCat, MoonCat, TomCat, and Galvanic Cat variants, each with different memory/buffer/transmon mode frequency configurations.\
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Hardware partners:\
- **Cryostats (dilution refrigerators)**: Bluefors\
- **Microwave control electronics**: Quantum Machines\
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## Platform: Helium System\
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Helium is Alice & Bob's first complete quantum computing platform, described as "the error correction lab" \'97 a full system designed to close the gap between quantum processors and today's supercomputers. It is the first multi-cat-qubit system made available to third-party organizations for error correction research and experimentation.\
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### Chip-level specifications\
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- 18 cat-qubits chip\
- Degree-2 connectivity\
- 1 logical qubit in the making\
- > 1 hour measured bit-flip time\
- 94.2% Z gate fidelity in 26.5 ns\
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### System-level specifications\
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- Dimensions: 2.4 m wide \'d7 3.3 m high \'d7 9 m long (21 m\'b2 footprint)\
- Cryostat temperature: 10 mK\
- Ambient air temperature: 20 \'b0C\
- Power consumption: 40 kW\
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### Physical architecture\
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The system comprises three main subsystems:\
- **Chandelier**: The cryogenic core, designed in Paris. At its heart is the mixing chamber \'97 one of the coldest places in the Universe \'97 where the quantum chip is housed in a bespoke case.\
- **Cooling system**: A Bluefors-partnered dilution refrigerator system maintaining the cryostat at 10 mK.\
- **Control electronics**: Precision microwave instruments that control individual qubits on the chip by sending microwave pulses through the cryostat.\
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### Site requirements\
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Room conditions for hosting a Helium system:\
- Temperature: 18\'9625 \'b0C\
- Noise level: maximum 60 dB\
- Humidity: 45\'9665 %\
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A condensed pre-installation guide is available for download at: https://alice-bob.com/wp-content/uploads/2026/06/Condensed-preinstallation-guide-Alice-and-Bob.pdf\
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### Control interface\
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Helium is operated through a unified software interface providing:\
- **Cat-qubit performance dashboard**: Visualize and access the dynamics of the 18-cat-qubit system; review performance of individual qubits.\
- **Real-time chip usage**: Track live chip-level usage; schedule and program jobs according to availability.\
- **Rack monitoring**: Monitor instruments individually with real-time performance data.\
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### Research access\
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Helium is available to external research partners for experiments on 18 noise-biased cat qubits, in collaboration with Alice & Bob's error-correction teams. Contact: partnership@alice-bob.com\
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Platform page: https://alice-bob.com/platform/\
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## Software Stack\
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Alice & Bob builds the full software pipeline from algorithm to physical execution:\
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1. **Algorithm layer**: Quantum circuit design (compatible with standard gate-based circuit descriptions)\
2. **Compilation layer**: Transpiles circuits to Alice & Bob's native gate set; bakes in error correction operations specific to cat qubit architecture\
3. **Pulse layer**: Converts compiled gates to microwave pulse sequences sent to control electronics\
4. **Measurement layer**: Reads probabilistic qubit measurement outcomes; post-processes into final answers\
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Alice & Bob uses NVIDIA CUDA-Q to accelerate quantum error correction research and simulation.\
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## Roadmap\
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Alice & Bob's public roadmap targets fault-tolerant quantum computing by 2030:\
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- **Now (2024-2026)**: Error-corrected logical qubit demonstrations (Helium chip); early FTQC systems for HPC integration\
- **2027-2028**: Multi-logical-qubit systems; early useful computations\
- **2030**: 100 logical qubits - sufficient for commercially valuable quantum advantage in chemistry, optimization, and cryptography-relevant problems\
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Roadmap systems in sequence: Helium \uc0\u8594  Lithium \u8594  Beryllium \u8594  Graphene (2030) \u8594  Next generation (upcoming)\
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Full roadmap PDF: https://alice-bob.com/wp-content/uploads/2024/12/Alice-Bob-Roadmap-Long-Version.pdf\
One-slide summary: https://alice-bob.com/wp-content/uploads/2024/12/Alice-Bob-Roadmap.pdf\
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## Key Publications\
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Foundational and landmark papers (all available on arXiv or peer-reviewed journals):\
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- Lescanne, Peronnin et al. - "Exponential suppression of bit-flips in a qubit encoded in an oscillator" (Nature Physics, 2020): https://www.nature.com/articles/s41567-020-0824-x\
- Guillaud, Mirrahimi - "Repetition cat qubit for fault-tolerant quantum computation" (Physical Review X, 2019): https://journals.aps.org/prx/abstract/10.1103/PhysRevX.9.041053\
- Reglade et al. - "Quantum control of a cat-qubit with bit-flip times exceeding ten seconds" (2023): https://arxiv.org/abs/2307.06617\
- Berdou et al. - "One Hundred Second Bit-Flip Time in a Two-Photon Dissipative Oscillator" (PRX Quantum, 2023): https://link.aps.org/doi/10.1103/PRXQuantum.4.020350\
- Gouzien et al. - "Performance Analysis of a Repetition Cat Code Architecture: Computing 256-bit Elliptic Curve Logarithm in 9 Hours with 126,133 Cat Qubits" (Physical Review Letters, 2023): https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.131.040602\
- Ruiz et al. - "LDPC-cat codes for low-overhead quantum computing in 2D" (2024): https://arxiv.org/pdf/2401.09541.pdf\
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Full publications list: https://alice-bob.com/publications/\
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## Use Cases and Target Applications\
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Alice & Bob positions its hardware as early FTQC for High Performance Computing (HPC) environments. Priority application domains:\
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- **Quantum chemistry**: Molecular simulation (e.g., complex molecules beyond classical tractability)\
- **Cryptography**: Elliptic curve discrete logarithm (demonstrated theoretically with cat qubit architecture)\
- **Optimization**: Combinatorial problems at scales unreachable classically\
- **HPC acceleration**: Quantum co-processor integrated alongside classical HPC clusters\
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HPC integration report: https://alice-bob.com/hpc-report/\
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## Scientific Board\
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External advisors from leading French research institutions:\
- Philippe Campagne-Ibarcq (Inria)\
- Emmanuel Flurin (CEA)\
- Benjamin Huard (Ecole Normale Superieure de Lyon)\
- Zaki Leghtas (Ecole Normale Superieure Paris)\
- Mazyar Mirrahimi (Inria)\
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## Key People\
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- **Dr. Theau Peronnin** - CEO\
- **Dr. Raphael Lescanne** - CTO\
- **Chloe Poisbeau** - COO\
- **Antoine Gras** - VP Engineering\
- **Dr. Jeremie Guillaud** - VP Firmware\
- **Philippe Muller** - VP Revenue & Business\
- **Juliette Peyronnet** - US General Manager (Boston)\
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## Resources for Agents and Developers\
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- Homepage: https://alice-bob.com\
- Platform (Helium system): https://alice-bob.com/platform/\
- Science explainer: https://alice-bob.com/science/\
- Engineering & architecture: https://alice-bob.com/engineering/\
- Roadmap: https://alice-bob.com/roadmap/\
- Publications index: https://alice-bob.com/publications/\
- Blog (latest research and company news): https://alice-bob.com/blog/\
- Glossary of quantum computing terms: https://alice-bob.com/glossary/\
- Whitepaper "Think Inside The Box" (accessible intro to cat qubits and roadmap): https://alice-bob.com/wp-content/uploads/2024/12/Think-Inside-The-Box-Alice-Bob-Whitepaper.pdf\
- Newsroom: https://alice-bob.com/newsroom/\
- Contact: https://alice-bob.com/contact/\
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## Terminology Notes for Agents\
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- **Cat qubit**: Alice & Bob's proprietary qubit type. Not to be confused with generic superconducting transmon qubits used by IBM, Google, etc. Cat qubits use two-photon dissipation to achieve passive bit-flip protection.\
- **Bit-flip**: Error that switches qubit state from 0 to 1 or vice versa. Suppressed exponentially in cat qubits.\
- **Phase-flip**: Error that switches qubit phase state (+/-). Requires active correction in cat qubit systems.\
- **Logical qubit**: Error-corrected qubit built from multiple physical qubits, capable of reliable long computations.\
- **Physical qubit**: The raw hardware qubit before error correction encoding.\
- **Overhead**: The ratio of physical to logical qubits required for error-corrected computation. Alice & Bob claims ~200x lower overhead than state-of-the-art alternatives.\
- **Felis**: Name of Alice & Bob's cloud quantum computing platform.\
- **Helium, Hydrogen, Boson, Lithium**: Names of successive Alice & Bob QPU chip generations.\
- **FTQC**: Fault-Tolerant Quantum Computing - the regime where logical error rates are low enough for useful long computations.\
- **Helium system**: Alice & Bob's first complete, externally-accessible quantum computing platform, built around an 18-cat-qubit chip. The system spans 21 m\'b2, consumes 40 kW, and operates at 10 mK.\
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## Documentation \
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- https://docs.dynamiqs.org \
- https://github.com/Alice-Bob-SW/qiskit-alice-bob-provider \
- https://felis.alice-bob.com/docs/\
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## Machine-readable \
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- https://alice-bob.com/sitemap.xml \
- https://alice-bob.com/feed \
- https://github.com/Alice-Bob-SW/qiskit-alice-bob-provider}