We demonstrate a new versatile building block for optical quantum technologies, enabling deterministic quantum engineering of light by combining the advantages of two complementary approaches: cavity quantum electrodynamics and interacting atomic ensembles. Our system is based on an intracavity Rydberg-blockaded atomic ensemble acting as a single two-level superatom. We coherently control its state and optically detect it in a single shot with 95% efficiency. Crucially, we demonstrate a superatom-state-dependent $\pi$ phase rotation on the light reflected from the cavity. Together with the state manipulation and detection, it is a key ingredient for implementing deterministic photonic entangling gates and for generating highly nonclassical light states.

中文翻译：

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用于光学量子工程的腔内里德堡超原子：相干控制、单次探测和光学π相移

我们展示了一种用于光学量子技术的新的多功能构建模块，通过结合两种互补方法的优势来实现光的确定性量子工程：腔量子电动力学和相互作用的原子系综。我们的系统基于腔内里德堡阻塞原子系综，充当单个两能级超原子。我们连贯地控制它的状态，并以 95% 的效率在一次拍摄中对其进行光学检测。至关重要的是，我们证明了超原子状态依赖$\pi$对从腔反射的光进行相位旋转。与状态操作和检测一起，它是实现确定性光子纠缠门和生成高度非经典光状态的关键因素。