Currently in his third-year as a PhD student, Charles obtained his engineering degree at Grenoble-INP Phelma, where he specialized in physics and electronic materials. Following his Master’s, he completed a final internship at the CNRS, before joining CEA-Leti to pursue a PhD thesis.
His paper, “
Superconducting Superlattices for Cryogenic Systems”, presented his research on the development of superconducting stacks and the measurement of their thermal conductivity at very low temperatures. This work was carried out in collaboration with CEA-Irfu, where the low temperature measurements in cryostat were performed.
How is heat controlled in a cryogenic system?
Developments of cryogenic systems, such as microcalorimeters for spatial applications or quantum processors, face common technological challenges, of which the thermal management, especially to limit the dissipation of embedded control circuits. To go further in miniaturizing such cryogenic circuits and systems, engineers and scientists are now exploring new micrometric interconnection solutions that will connect chips in a system while keeping them thermally insulated.
In this context, Charles is using superconducting materials, which are known to be poor thermal conductors. By creating a multilayer architecture that stacks two separate superconductors, niobium (Nb) and titanium nitride (TiN), he is able to further minimize the thermal conduction by reducing the phonon contribution.
A first proof of concept, presented at the ESTC conference, demonstrated that the TiN/Nb multilayer structure, manufactured on the CEA-Leti’s 200 mm platform, effectively disrupts heat transport at cryogenic temperatures, drastically reducing the thermal conduction.
Charles Bon-Mardion was thrilled to receive the prize, and underlined how important the teamwork and the engagement around his research are:
“Not only does this award recognize our work, but it will also motivate us to continue exploring new ideas. It encourages me to go deeper and to contribute even more to developing innovative thermal management solutions.”
Charles and teams at CEA-Leti and CEA-Irfu are currently developing a demonstrator that will integrate this TiN/Nb multilayer technology into interconnections with diameters of a few tens of micrometers, with a medium-term ambition of embedding them into an operational cryogenic system.