Project Manager

William Legrand, CNRS Researcher at Institut Néel

The MAGNON-BRAQET project aims to overcome one of the main obstacles limiting the integration of magnetic components into cryogenic devices for quantum computing: magnetic losses in ultra-thin magnetic insulators. The goal is to develop a new hybrid platform combining low-loss iron garnets with superconducting metals, in order to design compact, efficient microwave devices suitable for cryogenic environments.

Challenges

> Current magnetic materials exhibit excessively high losses at low temperatures. Finding nearly lossless iron garnet compositions is a major challenge.

> Integrating these materials into cryogenic environments (a few kelvins) while preserving their properties is technically complex.

> Ensuring perfect synergy between magnetic materials and superconducting circuits, without detrimental interference, is critical.

> Achieving miniaturized circulators and isolators while maintaining their traditional performance poses a significant technological challenge.

> Demonstrating that the developed devices operate effectively under real-world conditions, particularly within quantum computing platforms, is essential.

Positioning the Project with the PEPR

> MAGNON-BRAQET is fully aligned with the objectives of the PEPR SPIN, particularly the SWING program, by extending integrated magnonics to cryogenic devices—a field that remains largely unexplored. It brings a new dimension by leveraging low temperatures for specific microwave applications.

The project is based on new magnetic materials, directly aligned with the SPINMAT theme, to achieve unprecedented performance in spintronics and magnonics. It also aims to bridge spintronics with quantum technologies, in strong synergy with the PEPR Quantum program.

Finally, MAGNON-BRAQET has strong potential for valorisation, with expected impact on the quantum industry. It aims to demonstrate the maturity of spintronics as both an autonomous and strategic technology for quantum applications.