Victor Gondret

I am a PhD student in the Quantum Atom Optics team at the Laboratoire Charles Farby, Institut d’Optique Graduaate School, Université Paris-Saclay. My research focuses on the entanglement of massive particles, probing coherence with atom interferometry.

The experimental setup on which I work is a ultra-cold atom machine that cool down metastable helium atoms to Bose-Einstein condensation (BEC). Since metastable helium atoms have a really high internal energy, it is possible to detect them with micro-channels plate (MCPs). This means that we can detect the arrival time of individual atoms as well as its impact position on the detector. Combined with time-of-flight measurements that give access to the in-trap momentum distribution, helium is a really nice species to study correlations.

In this illustration, every data point corresponds to the velocity of an individual atom. The experimental setup involved colliding two Bose-Einstein Condensates (BECs), resulting in the formation of a halo comprised of entangled particles. Each point on the spherical surface is entangled with its counterpart on the opposite side. The regions with the highest density at the top and bottom of the sphere represent the locations of the two BECs.

We also perform atomic interferometry using laser light to perform Bragg diffraction. This makes possible to study the coherence between two massive wavepackets and therefore to probe entanglement and non-classical effects.