En vidéo-conférence : https://us02web.zoom.us/j/81656390443?pwd=RkZMMHdOUDNmV3VxQlR3U0RNMDYzUT09 – 29 mai 2020 à 14H (ID de réunion : 816 5639 0443 – Mot de passe : 9skFjR)
Our experimental setup allow us to prepare and manipulate circular Rydberg atoms which are of great use for metrological applications. The topic of this PhD thesis is the experimental implementation of optimal control theory (OCT) to the preparation of arbitrary states of rubidium Rydberg atoms.
So far, preparing circular Rydberg states with high fidelity required to perform an adiabatic passage, which implies the use of µs-long radiofrequency (RF) pulse. During this work, in collaboration with S. Patsch and C.P. Koch from the University of Kassel for the theory part, we experimentally implement RF pulses obtained using the Krotov method, and prepare circular Rydberg states with a fidelity of 96.2% in only 113 ns. Moreover, we show that OCT can also be applied to prepare more complex states, and demonstrate the preparation of a superposition of a circular state and a low angular momentum state, which has application to metrology. We reach a fidelity of 93% with a 167 ns-long pulse, which is a remarkable improvement in comparison to the previously used technique.