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§ Private Profile · Paris, France
Quantum computing developer creating scalable quantum processors using carbon nanotubes for fault-tolerant quantum computing.
Based in Paris, France, C12 Quantum Electronics develops scalable quantum processors utilizing carbon nanotubes as quantum transistors to enable fault-tolerant quantum computing. The company integrates these high-fidelity qubits onto silicon chips through a proprietary nano-assembly process, creating application-specific hardware alongside software tools like the Callisto quantum emulator. Founded in 2020 by twin brothers Pierre and Matthieu Desjardins as a spin-out from the ENS Physics Lab, the enterprise has raised over 28 million euros in equity funding. This capital includes a recent 18 million euro pre-Series A round led by 360 Capital to support their 800-square-meter fabrication hub, ten patent families, and 60 personnel with 22 doctorates. C12 Quantum Electronics recently published breakthrough coherence time research for carbon nanotube quantum states in Nature Communications, further advancing their mission to serve industry partners.
C12 Quantum Electronics has raised $64.6M across 4 funding rounds.
C12 Quantum Electronics has raised $64.6M in total across 4 funding rounds.
C12 Quantum Electronics has raised $64.6M across 4 funding rounds. Most recently, it raised $16.3M Grant in December 2025.
| Date | Round | Lead Investors | Other Investors | Status |
|---|---|---|---|---|
| Dec 19, 2025 | $16.3M Grant | — | — | Announced |
| Jun 19, 2024 | $19.3M Venture Round | — | Nader Sabbaghian, BNP Paribas Développement, Clémentine Boussac (cazenave), EIC Fund, Didier Valet, Verve Ventures | Announced |
| Jun 1, 2024 | $19M Series U | — | Motier Ventures | Announced |
| Jun 1, 2021 | $10M Seed | — | 360 Capital Partners, Airbus Ventures, B Capital Group, Incisive Ventures, Negev Capital, Pioneer Fund, Prithvi Ventures, Ravelin Capital, Satori Capital, What IF Ventures, Octave Klaba, BNP Paribas Développement, Olivier Rameil | Announced |
C12 Quantum Electronics is a Paris-based quantum computing company developing a carbon‑nanotube (CNT)–based spin‑qubit processor that aims to deliver higher qubit stability and a scalable fabrication path by combining ultra‑pure carbon materials with semiconductor manufacturing techniques[3][1].
High‑Level Overview
C12’s mission is to build the next materials‑driven generation of quantum processors using carbon nanotubes to improve qubit coherence and reduce error rates compared with many existing qubit modalities[3][1].Its investment and business model focuses on technology commercialization: raising venture capital to scale device fabrication, partnering with research and industrial foundries, and offering developer access tools such as a cloud emulator called Callisto to onboard users before large‑scale hardware is available[5][6].Key sectors targeted are industries that will demand high‑fidelity quantum hardware for complex optimization and simulation problems (examples cited by C12 and analysts include pharmaceuticals, logistics and finance)[4][1].C12’s impact on the startup and research ecosystem includes advancing a materials‑centric qubit approach, developing an industry‑friendly fabrication flow that leverages existing semiconductor infrastructure, and providing early developer tooling to build a user base ahead of full hardware availability[4][3][5].
Origin Story
C12 was founded in January 2020 as a spin‑off from the Physics Laboratory of the École Normale Supérieure in Paris, launched by twin brothers Matthieu and Pierre Desjardins to commercialize over a decade of CNT research led by Takis Kontos and collaborators[3][2].The idea emerged from lab demonstrations of spin‑photon coupling in ultra‑clean carbon nanotubes and a patented nano‑assembly technique that places CNTs onto semiconductor chips, enabling preselection of qubits and a potentially more scalable path to low‑error devices[2][3].Early traction included seed financing (a $10M seed round in 2021 referenced by press coverage), the build‑out of an in‑house production line making roughly one chip per week during early commercialization, creation of the Callisto emulator, and follow‑on funding rounds raising tens of millions for growth and partnerships[2][5][4].
Core Differentiators
Role in the Broader Tech Landscape
C12 rides the materials‑first trend in quantum hardware where improving coherence and manufacturability at the materials and device level is viewed as essential to reach fault tolerance and practical advantage[4][2].Timing matters because industrial users and software developers are preparing for quantum advantage while hardware platforms still struggle with error rates and scaling; a materials innovation that improves qubit quality could become a competitive lever as demand materializes[4][6].Market forces in C12’s favor include growing venture funding for quantum startups, increasing industrial partnerships with foundries and labs, and a rising need for developer tooling and emulation to seed future demand[5][4][1].If successful, C12’s approach could diversify the hardware ecosystem (adding a carbon‑based spin‑qubit contender) and influence foundry practices by demonstrating CNT integration techniques compatible with semiconductor workflows[3][4].
Quick Take & Future Outlook
Near term, expect C12 to continue validating multi‑qubit elements, scale its production throughput, expand partnerships with foundries and industrial customers, and grow its developer and research user base via Callisto and pilot collaborations[5][4].Medium term, key milestones to watch are demonstrations of two‑qubit operations at practical distances on chip, steady improvements in qubit fidelity, and movement toward fault‑tolerant building blocks (dozens of logical qubits per roadmap)[5][4].Risks include the inherent scientific and engineering challenges of translating lab CNT demonstrations into large‑scale, reliable processors and competition from other qubit modalities that are also rapidly improving[4][2].If C12 achieves its roadmap goals, it could become a distinctive materials‑led hardware provider that accelerates industrial adoption of quantum computing by offering higher‑quality qubits with a clearer fabrication scaling path[4][3].
Key sources: C12’s company site and about page[3][6], a detailed SME case study and roadmap PDF[4], reporting on fundraising and operations[5], and technical/lab background from LPENS and ONERA coverage[2][1].
C12 Quantum Electronics has raised $64.6M in total across 4 funding rounds.
C12 Quantum Electronics's investors include Nader Sabbaghian, BNP Paribas Développement, Clémentine Boussac (Cazenave), EIC Fund, Didier Valet, Verve Ventures, Motier Ventures, 360 Capital Partners, Airbus Ventures, B Capital Group, Incisive Ventures, Negev Capital.