High-Fidelity Quantum Computing with Carbon Nanotubes

Project Information

HiFiQC

Grant agreement ID: 190125825

DOI

10.3030/190125825

Project closed

EC signature date 14 December 2022

Start date 1 January 2023

End date 31 December 2024

Funded under

• The European Innovation Council (EIC)

Total cost

€ 3 570 000,00

EU contribution

€ 2 499 000,00

Coordinated by

C12 QUANTUM ELECTRONICS
France

Periodic Reporting for period 2 - HiFiQC (High-Fidelity Quantum Computing with Carbon Nanotubes)

Reporting period: 2024-01-01 to 2024-12-31

Summary of the context and overall objectives of the project

Quantum computing has the potential to revolutionize various industries, including healthcare, finance, and materials science. It can enable the development of new drugs, more accurate financial models, and innovative materials. For Europe, quantum computing is crucial for maintaining competitiveness in a rapidly evolving technological landscape. By investing in quantum computing research and development, Europe can position itself as a leader in this transformative technology and secure its long-term economic prosperity.
C12 Quantum Electronics builds reliable quantum processors powered by the most elementary material: carbon nanotubes. By using single-electron spins hosted in suspended ultra-clean carbon nanotubes, we achieve the closest realisation of an ideal qubit in vacuum.
We integrate the nanotubes onto semiconductor chips thanks to our proprietary high-throughput technique. Any qubit can be coupled to another long-distance qubit through a custom microwave superconducting resonator. Thereby, we achieve scalable & ultra-coherent quantum processor architecture with isolated yet easily addressable qubits.
Our carbon nanotube based technology can scale quantum computing, in the vein of what silicon did for classical computing. Combining the purity of carbon nanotubes and well-established semiconductor manufacturing, our innovation has the potential to process quantum information at large scales with the highest fidelity. Thus, our quantum computers will solve complex problems beyond the reach of any classical supercomputer.

Work performed from the beginning of the project to the end of the period covered by the report and main results achieved so far

The project was supporting this main goal, to build a quantum computer. Our progress towards this goal was divided through three scientific objectives :
5-Qubit Demonstrator : this objective has been postponed after the end of the project, we are now focusing on a 2 qubit demonstrator.
- So far, we managed to produce a report on high-quality resonators & test results as well as a silicon chip layout for 2 qubits.
- The production of the 2-qubit demonstrator has started.
- We have produced a report detailing 1 qubit gate fidelity while 2-qubit gate fidelity and cross-talk characterization will soon be achieved.
- We have developed a detailed roadmap to reach the 5 Qubit-demonstrator.

- Quality Factor 10000 per qubit (Advanced C12 Qubits) : We have demonstrated that the quality factor previously announced will not be a requirement to develop a useful 2 Qubit demonstrator. For commercial purposes, the demonstrator will be efficient with a lower qubit quality factor, even though we are working on it to improve it. The qubit quality factor is a ratio between coherence time and the quality factor of the microwave resonator. We were able to demonstrate that the recent tests on high-impedance microwave resonators are conclusive and improve the microwave resonator quality factor, thus improving the qubit quality factor to a level that is good enough for commercial validation.
Even though we initially targeted a very high quality objective, we received customer feedback explaining that we have already reached a good enough quality and that it is now more important to focus on the scaling of the qubits (first 2 qubits and then 5 qubits). The progress on the quality of the qubits are progressing in parallel and a quality factor with a value of 10000 is expected to be achieved in 2026.
Integration into Quantum Software Ecosystem : We have achieved to create an operating system architecture & drivers development - our results are presented in a report on operating systems, including low-level control systems. We also produced a report on virtual gates, more precisely on machine learning algorithm tuning quantum dots.
Regarding cloud integration, we already launched a simulator of our quantum computer called Callisto plugged-in with APIs to cloud - It has already been tested and used by external users. We have a roadmap to develop it further over the next year.

Progress beyond the state of the art and expected potential impact (including the socio-economic impact and the wider societal implications of the project so far)

Our new offices reflect our commitment to innovation and efficiency. Equipped with cutting-edge technology, they have reduced our R&D iteration time from months to just 6-8 weeks, accelerating our quantum computer development.

In the short term, we focus on quantum chip applications for chemical reaction simulations. C12 collaborates with Air Liquide to optimize thin metal layer deposition, studying both thermodynamics and kinetics. Early results show strong potential, leading to further studies. We also partner with a defence industrial player and the French Ministry of Defence (DGA).

Long-term, our technology will address key challenges in quantum computing, confirmed by our first measured qubit’s fidelity, connectivity, and scalability. Quantum simulations will impact drug discovery, battery design, finance, logistics, AI, and cybersecurity. While quantum computing’s full potential remains decades away, breakthroughs could accelerate progress.

Regarding communication, our project is featured on our company website. We’ve successfully raised awareness, especially in France, through ministerial visits, media coverage, and regional support. Our goal is to expand communication across the EU and globally.

Inauguration of our new labs

Pictures of our new laboratory, where we iterate our R&D process