Laboratory link : http://irfu.cea.fr/dacm/Phocea/Vie_des_labos/Ast/ast_groupe.php?id_groupe=3301
Since their discoveries at the beginning of the twentieth century, the unique properties of superconductivity have been used in a wide variety of applications from powerful electromagnets used in MRIs and fusion reactors, to next generation electronic fast digital circuits (Quantum-bits) and particle accelerators. Major causes for performance limitations in a superconductor originate from its interaction with external electro-magnetic fields which are responsible for the entire electromagnetic behavior of applied superconducting materials. We propose an original approach to mitigate the superconducting dissipation originating from deleterious vortices: a new superconducting multilayer as efficient screening structure to inhibit vortices entry into the bulk superconductor. The synthesis and design of these nano hetero-structures by Atomic Layer Deposition will be optimized and tailored to drastically improve the performance of a superconductor-based device: superconducting radio frequency (SRF) cavities.
The PhD student will be an important active part of the synergistic approach between synthesis, design, characterization and performance tests of the most effective screening hetero-structures based on the superconducting nitride alloys NbN, NbTiN, MoN and insulating materials AlN, MgO, SrTiO3 in order to provide a technological breakthrough towards unprecedented superconductor performances for superconducting resonators. This 3 years program will focus on three research thrusts or work packages:
1- Explore synthetic routes to deposit innovative hetero-structures. Years 1-2.
2- Tailor hetero-structure properties to optimize superconductor performances. Years 2-3
3- Test optimized hetero-structure on superconducting Nb resonators. Year 3.