# 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.