GHz Rabi flopping to Rydberg states in hot atomic vapor cells
  We report on the observation of Rabi oscillations to a Rydberg state on a timescale below one nanosecond in thermal rubidium vapor. We use a bandwidth-limited pulsed excitation and observe up to 6 full Rabi cycles within a pulse duration of ~ 4 ns. We find good agreement between the experiment and numerical simulations based on a surprisingly simple model. This result shows that fully coherent dynamics with Rydberg states can be achieved even in thermal atomic vapor thus suggesting small vapor cells as a platform for room temperature quantum devices. Furthermore the result implies that previous coherent dynamics in single atom Rydberg gates can be accelerated by three orders of magnitude. 
B. Huber, T. Baluktsian, M. Schlagm\"uller, A. K\"olle, H. K\"ubler,   R. L\"ow, and T. Pfau
quant-ph physics.atom-ph