Experimental setup for fast loading of a miniaturized cavity : toward an atomic qubits register
Claire Lebouteiller (LKB)

The study of quantum entanglement is a very active research field. Cavity quantum electrodynamics systems are versatile tools allowing for instance entanglement in mesoscopic systems, that is to say with about a hundred particles.
The purpose of the new experimental setup built during this thesis is to reach the single atom manipulation and detection level while working with mesoscopic ensembles, collectively coupled to the cavity mode. Toward this goal, three new experimental techniques have been developed to enable reliable and fast data acquisition rate, essential to reconstruct entangled states by quantum tomography means. First, robust extended cavity diode lasers have been constructed, allowing acquisitions that last for days. Then, a pulsed atomic source has been set up, it combines the advantages of fast magneto-optical trap loading and long lifetime in conservative traps by modulating the pressure inside a single vacuum chamber apparatus on a short timescale. Finally, to ensure the fast transport of cold atomic ensembles from the magneto-optical trap to the cavity position, a dipole trap moved with an acousto-optic deflector has been built. This allows a transport over few centimetres leaving the full optical access to the atomic cloud for other manipulations.
Thanks to this new experimental setup, we hope to contribute to the understanding of the rich physics lying beyond multi-particle entangled systems.