讲座题目：Single photon scattering in a Rydberg atom photon transistor
主讲人：李伟斌教授（英国诺丁汉大学）
主持人：黄国翔教授
讲座时间：2016.12.30 15:00
讲座地点：理科大楼A814室
报告摘要：
Recent experiments have realized an all-optical photon transistor using a cold atomic gas. This approach relies on electromagnetically induced transparency (EIT) in conjunction with the strong interaction among atoms excited to high-lying Rydberg states. The transistor is gated via a so- called Rydberg spinwave, in which a single Rydberg excitation is coherently shared by the whole ensemble. In its absence the incoming photon passes through the atomic ensemble by virtue of EIT while in its presence the photon is scattered rendering the atomic gas opaque. An important current challenge is to preserve the coherence of the Rydberg spinwave during the operation of the
transistor, which would enable for example its coherent optical read-out and its further processing in quantum circuits. With a combined eld theoretical and quantum jump approach and by employing a simple model description we investigate systematically and comprehensively how the coherence of the Rydberg spinwave is a ected by photon scattering. With large-scale numerical calculations we show how coherence becomes increasingly protected with growing interatomic interaction strength. The theoretical model is experimentally veried recently.