French quantum computing startup C12 Quantum Electronics has raised €18 million ($19.4 million) in a pre-Series A funding round.

The raise was led by Varsity Capital, EIC Fund, and Verve Ventures, and included participation from previous investors 360 Capital, Bpifrance, and BNP Paribas Développement.

Spun out of the physics laboratory of the École Normale Supérieure in Paris, C12 was founded in 2020 by twin brothers Pierre and Matthieu Desjardins. The company currently employs 45 people and is working to develop a carbon nanotube-based quantum computer, a technology that involves the integration of carbon nanotubes onto semiconductors.

The company says this approach should improve the stability and quality of qubits while minimizing the error rate, with C12 ultimately striving to design and build a large-scale, fault-tolerant quantum computer.

The company raised an initial $10 million in 2021 and in October 2023, C12 inaugurated a pilot line at its Quantum Fab in Paris, allowing the company to start producing its own quantum servers. In addition to several production workshops, the facility also includes a cleanroom for the semiconductors.

Writing on LinkedIn, Matthieu, who serves as CTO of C12, wrote that he was “incredibly proud” to announce the funding round, adding that the “achievement marks a significant milestone in C12's journey.”

He continued: “Reflecting on our journey, I am sincerely amazed by our scientific progress and technical achievements. Looking ahead, I am genuinely impressed by the potential of our carbon nanotube technology and the extraordinary capabilities of our team.”

His brother Pierre, C12’s CEO, wrote in his own post: “This second round of financing is a solid validation of the dedication and innovative potential of our incredible team and the exceptional first results achieved.”