Extending optical nonlinearity into the extremely weak light regime is at the heart of quantum optics, since it enables the efficient generation of photonic entanglement and implementation of photonic quantum logic gate. Here, we demonstrate the capability for continuously tunable single-photon level nonlinearity, enabled by precise control of Rydberg interaction over two orders of magnitude, through the use of microwave-assisted wave-function engineering. To characterize this nonlinearity, light storage and retrieval protocol utilizing Rydberg electromagnetically induced transparency is employed, and the quantum statistics of the retrieved photons are analyzed. As a first application, we demonstrate our protocol can speed up the preparation of single photons in low-lying Rydberg states by a factor of up to ∼40. Our work holds the potential to accelerate quantum operations and to improve the circuit depth and connectivity in Rydberg systems, representing a crucial step towards scalable quantum information processing with Rydberg atoms.

中文翻译：

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使用 Rydberg 状态波函数工程的连续可调单光子级非线性


将光学非线性扩展到极弱的光域是量子光学的核心，因为它能够有效地产生光子纠缠和实现光子量子逻辑门。在这里，我们展示了通过使用微波辅助波函数工程在两个数量级上精确控制里德堡相互作用来实现连续可调的单光子级非线性的能力。为了表征这种非线性，采用了利用 Rydberg 电磁感应透明度的光存储和检索协议，并分析了检索到的光子的量子统计。作为第一个应用，我们证明了我们的协议可以将低洼里德堡状态中单光子的制备速度提高高达 ∼40 倍。我们的工作有可能加速量子运算并改善里德堡系统中的电路深度和连接性，这代表了使用里德堡原子进行可扩展量子信息处理的关键一步。