Coherent transfer between low-angular momentum and circular Rydberg states. (arXiv:1703.05918v1 [quant-ph])

We realize a coherent transfer between a laser-accessible
low-angular-momentum Rydberg state and the circular Rydberg level with maximal
angular momentum. This transfer is induced by a radiofrequency field with a
high-purity $\sigma^+$ polarization tuned at resonance on Stark transitions
inside the hydrogenic Rydberg manifold. We observe over a few microseconds more
than twenty coherent Rabi oscillations between the initial Rydberg state and
the circular Rydberg level. We characterize in details these complex
oscillations involving many Rydberg levels and find them to be in perfect
agreement with a simple theoretical model. This coherent transfer procedure
opens the way to hybrid quantum gates bridging the gap between optical
communication and quantum information manipulations based on microwave Cavity
and Circuit Quantum Electrodynamics.