Berlin 2014 – scientific programme

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SYQR: Symposium Quantum Repeater

SYQR 4: Photon Sources for Quantum Networks

SYQR 4.7: Talk

Tuesday, March 18, 2014, 15:30–15:45, Kinosaal

Rydberg gases at room temperature - pulsed four-wave-mixing down to volumes of a few cubic micrometers — •Andreas Kölle, Bernhard Huber, Fabian Ripka, Robert Löw, and Tilman Pfau — 5. Physikalisches Institut, Uni Stuttgart

The van-der-Waals interaction between Rydberg-excited atoms provides an interaction range on the micrometer scale. Various experiments in cold atomic clouds demonstrated the feasibility of using Rydberg states for quantum devices like single photon sources. In our experiments, we want to transfer these results to thermal vapor cells of the size of the Rydberg-Rydberg interaction length scale, which are more favorable in terms of scalability and handling. In comparison to an ultra-cold atomic cloud, thermal cells have the disadvantage of thermal atomic motion and the resulting Doppler shift. To overcome this effect we perform our excitation to the Rydberg state on the nanosecond timescale. We present our results of a pulsed four-wave-mixing scheme via a Rydberg state. We observe four-wave-mixed light emission on a nanosecond time scale with a non-trivial temporal evolution which can be described by a coherent interference within the Doppler ensemble. Furthermore we discuss our experimental effort to reduce the excitation volume to a sub micrometer length scale in all 3 dimensions.