C12 and Quobly: laboratories and qubits to build quantum computing in Europe

Carbon nanotube qubits

The startup C12 Quantum Electronics is working on qubits based on suspended carbon nanotubes. These structures offer high electronic confinement and potentially long coherence times. The commissioning of its 1,000 m² underground laboratory in Paris addresses the need to control vibrations and electromagnetic interference. The facility includes cleanrooms, cryostats to cool the qubits to a few millikelvins, and equipment for integrating quantum circuits. C12 will assemble prototype processors there and develop manufacturing methods compatible with larger-scale production.

Silicon spin qubits

Quobly , formerly Siquance, offers spin qubits manufactured on standard silicon wafers. This technology benefits from decades of experience in the semiconductor industry and could be more easily scalable. Advances presented in March 2026 focused on integrating multiple qubits on the same chip with precise control of interactions. The company also unveiled a roadmap aiming to achieve a scalable quantum processor by 2032. Using silicon allows for the utilization of existing production lines and reduces costs, but requires addressing challenges related to spin uniformity and defect management.

Importance of infrastructure

C12's underground laboratory signals that quantum research is entering the industrialization phase. Reaching scale requires more than just high-performance qubits; mastering manufacturing, integration, and packaging is essential. Underground or isolated infrastructures are often necessary to protect against seismic vibrations and urban noise. These investments also bridge the gap between academic research and industrial production, a prerequisite for delivering processors to industrial partners and data centers.

Diversification of methods and sovereignty

In France, several approaches to quantum computing coexist: "cat" qubits (Alice & Bob), neutral qubits (Pasqal), carbon nanotubes (C12), and silicon spins (Quobly). This diversification reflects a portfolio strategy: by investing in several technological platforms, the country increases its chances of achieving a viable solution. It also strengthens European sovereignty by covering different hardware components.

Source: https://thequantuminsider.com/2026/03/31/french-national-quantum-update-march-2026/#:~:text=At%20the%20technical%20layer%2C%20progress,France%E2%80%99s%20diversified%20bet%20across%20modalities