Electronic transport at the nanoscale is an important field of condensed matter physics. Thanks to nanofabrication improvements it is now possible to study conduction through confined electronic states. Among those new possibilities one can underline the possibility to build quantum bits using superconductors or electronic spins. One can also think about hybrid structures with different conductors to highlight exotics states of matter. Probing, manipulating and coupling individual quantum systems is feasible with cavity quantum electrodynamics (cQED) which deals with the interaction between light and matter at the most elementary level. Recently, these methods have been developed in the context of mesoscopic physics. In such mesoscopic quantum electrodynamics (mesoQED) architectures, the tools of cavity QED have been shown to allow us to probe with a very high sensitivity intricate charge or spin dynamics in nanoscale devices.
In the HQC group of LPENS, we have developed such systems with carbon nanotubes as elementary conductor and CPW resonator as probe. This has enabled to show coherent coupling between individual spins and cavity photons [1,2]. Now we are developing a 2.5D fully modular cavity to perform single qubit operations and 2 qubit gates.
 J.J. Viennot, M.C. Dartiailh, A. Cottet and T. Kontos Science 349, 408 (2015)
 T. Cubaynes et al. npj Quant. Inf (2019)