Quantum Optics Laboratory

Abstract: 

A thermal photonic quantum device is intrinsically reproducible and scalable, towards the potential application of the photonic-based quantum security communication and information processing. We first studied the strong Rydberg-atom interactions in thermal vapors confined in a cell with mm scale. The coherent Rydberg dynamics on nanosecond timescales and van-der Waals interatomic interaction in a three-level system have been observed. In addition, we implemented a pulsed four-wave-mixing (FWM) scheme to observe both coherent dynamics and effects of dephasing due to Rydberg-Rydberg interaction. In a double-pulsed FWM transition, we were able to create, store and retrieve collective Rydberg polaritons. The measured lifetime of stored coherence was around 1 ns, limited by motional dephasing of the thermal vapors. We are going to reduce the excitation volume towards below the Rydberg interaction range (the blockade volume) for generating a deterministic single-photon source.