Coherent excitation of Rydberg atoms in micrometre-sized atomic vapour cells

The coherent control of mesoscopic ensembles of atoms and Rydberg atom blockade are the basis for proposed quantum devices such as integrable gates and single-photon sources. To date, experimental progress has been limited to complex experimental set-ups that use ultracold atoms. Here, we show that coherence times of ∼100 ns are achievable with coherent Rydberg atom spectroscopy in micrometre-sized thermal vapour cells. We investigate states with principle quantum numbers between 30 and 50. Our results demonstrate that microcells with a size on the order of the blockade radius (∼2 µm), at temperatures of 100–300 °C, are robust and promising candidates for investigating low-dimensional strongly interacting Rydberg gases, constructing quantum gates and building single-photon sources. Rydberg blockade — the suppression of excitation of more than one Rydberg atom within a blockade volume — has so far been realized using ultracold atoms. Now, scientists show that coherence times of >100 ns are achievable with coherent Rydberg atomic spectroscopy in micrometre-sized thermal vapour cells, making them good candidates for investigating low-dimensional strongly interacting Rydberg gases, constructing quantum gates and building single-photon sources.