C12

On Wednesday 17 June, C12's CEO & Co-founder Pierre Desjardins will take the stage at Economist Impact events' Commercialising Quantum conference in London 🇬🇧 from 09:30–10:00 GMT, on one of the most debated questions in #quantum hardware: "Why qubit quality could matter more than quantity." At C12, we build spin qubits on carbon nanotubes, engineered for coherence and fidelity from the ground up, on the belief that the #quantumcomputing systems that last will be the ones that got quality right from the start. If you're attending, we hope to see you there.

🌟 We are thrilled to welcome Julien Sarry to C12 as our new Head of Engineering, here to turn the industrial frontier of quantum computing into reality. Very few people in the world have taken a deep technology from the lab to mass production and Julien has done it twice. For nearly eight years at Apple in Cupertino, he led the programmes that brought LiDAR and camera modules to multiple generations of iPhone Pro and iPad Pro, shipping to hundreds of millions of people. Before that, he co-founded a LiDAR startup and industrialised sensing technologies that are still in production today in the Vaisala range. Now he brings that rare expertise to #QuantumComputing. At C12, his mission is to build the production, testing, and validation capabilities that take our hardware from the lab to the factory floor, and to build the engineering organisation and culture needed to execute at scale. 💬 As Julien puts it: "The science is there. Now the challenge is making it manufacturable, reliable, and reproducible. That is exactly what I am here to build." We could not be more excited to have him on board. 🌍 C12 keeps growing and we are incredibly proud of the team we are building. 80 strong, 27 nationalities, all based in the heart of Paris. If building the future of quantum hardware sounds like your kind of challenge, head to our website to discover our open roles. #DeepTech #Engineering

C12 is part of France's quantum bet 🇫🇷 On the occasion of the Forum européen des technologies de calcul, du quantique et des semi-conducteurs and today's announcements by Emmanuel Macron on France's National Quantum Strategy, we are proud to be one of 25 quantum laureates contributing to French excellence under #France2030. Thank you to the State, and in particular to Secretary general for investment, Bpifrance and ANR, the French National Research Agency, for backing our work on carbon-nanotube spin qubits ⚛️, the materials-first bet that allows us to address technological sovereignty at the layer of the stack where it is hardest to build. From our quantum lab in the heart of Paris, we are working to strengthen French competitiveness in #quantum hardware, accelerate the path from research to manufacturable processors, and train the engineers and operators who will run a real industrial quantum stack 🇪🇺 At France 2030 and the SGPI, Bruno Bonnell, Géraldine Leveau, Massis Sirapian and Loïc Le Loarer. At the government level, Sébastien Lecornu and Philippe Baptiste.

Last week, Andrea Mammola represented C12 at Q.Stack 2026 🇮🇹 in Bologna, joining the panel "European Quantum Hardware: Industrial Scalability and Strategic Dependencies" alongside Kabir Leonardo Chhabra, Cecile M. Perrault, and Michele Dallari. The discussion surfaced a few themes: 🔹 Sovereignty starts at the material level Scaling #quantum hardware requires control across the stack, from materials and fabrication to architecture and software. 🔹 The bottleneck is industrialisation The challenge is no longer the science itself, but turning research into manufacturable, deployable systems. 🔹 Scaling needs stronger demand signals Procurement, coordinated investment, and early collaboration between startups and industrial players will shape whether Europe can scale competitively. At C12, this approach is already embedded in how we build, from growing our own carbon nanotubes to fabricating chips in-house in Paris and scaling quantum hardware within a European ecosystem ⚛️ #DeepTech #EuropeanTech

A few weeks ago C12 shared its #roadmap to useful fault-tolerant quantum computing, and this is a closer look behind its four systems ⚛️ Aïdôs, Zélos, Styx, and Panopeia each represent a distinct stage in the progression from first logical operations to utility-scale #quantum computing by 2033.🏛️ Designed around a modular architecture, every system introduces the foundations required for the next: from #errorcorrection and chiplet integration to large-scale replication and sustained fault-tolerant computation For further details on the roadmap and architecture, see the link in the comments👇

C12 keeps building, and we're #hiring 🚀 Four new roles open across commercial leadership, customer delivery, fault-tolerant architecture, and quantum measurement software, the teams turning our carbon nanotube #quantum hardware into machines designed to scale. We're 80+ in the heart of Paris, blending deep tech, precision engineering, and bold ambition. We're looking for sharp new minds to join. Open roles in the carousel and comments below 👇 #careers

Last week, Lydia Baril, C12's Head of Innovations and Partnerships, spoke at #QUANTUMatter 2026 🇪🇸 on what it actually takes to scale quantum computing. And the answer has less to do with qubit counts than most people assume. Lydia's argument cuts through a lot of noise in the field. The kind of qubit you build around determines whether scale is achievable, and right now, most approaches are hitting the same ceiling. 🔹 Cryogenic overhead, wiring density, and cost don't improve as you add more qubits. They become the bottleneck, compounding with every step up. 🔹 Carbon-nanotube spin qubits, paired with a high-impedance microwave bus, are designed to avoid that ceiling rather than delay it. 🔹 The early signal is already there, from radar-tracking optimisation with Thales to early chemistry work in semiconductors, all run on Callisto, our quantum emulator. At C12, real progress in #Quantum hardware has always started at the material level, and everything else builds from there🔬 Learn more about how we're building it, link in the comments 👇 #Deeptech

Last week Andrea Mammola and Chloé Ai, PhD brought C12 to Quantum Computing Theory in Practice (QCTiP)  hosted by the 🇬🇧 University of Oxford Andrea presented our work on #quantum walks and (1+1)-QED simulations via QCA. Two threads, one poster: QW algorithms benchmarked on Callisto, our hardware emulator, and early Schwinger model simulations on C12's carbon nanotube cQED architecture ⚛️ Key takeaways: 🔹 QCA as a concrete NISQ framework  Close-to-physics formulation, native iSWAP and √iSWAP gates only, linear scaling in depth and gate count. 🔹 Grounded benchmarking  Callisto reflects the real constraints of C12's carbon nanotube spin-qubit processor, keeping results honest 🔹 Towards quantum field theory on hardware  First simulations of Schwinger model dynamics via QCA, opening a path to early NISQ simulations of (1+1)-QED 🌐 Dive into the full paper in the comments 👇 #QCTiP2026 #QuantumComputing

What does it take to lead on #quantum in Europe? 🌍 Pierre Desjardins, co-founder and CEO of C12, shares his perspective in Choiseul Magazine as part of the 2026 #Choiseul100. Technological leadership has always determined economic and strategic power, and #quantumcomputing is the next frontier. Europe has a strong ecosystem, and backing it with the right investment and coordination is what the moment calls for. At C12, we are building toward it with spin qubits in ultra-pure carbon nanotubes, engineered for the coherence and connectivity that scaling demands ⚛️ 🔗 Link to the full article (in French) in the comments below

🇫🇷 C12 is heading to the France Quantum Conference. 📅 June 16th, Station F, Paris Our CEO & Co-founder Pierre Desjardins will take the stage to walk through C12's roadmap to scalable, fault-tolerant #quantum computing - the milestones, the architecture, and what the path to real-world impact looks like. Now in its 5th edition, #FranceQuantum is one of the highlights of the quantum calendar and this year, we have a lot to share. See you there! 🚀 🔗 Learn more about our roadmap in the comments below.