Plenty of quantum information protocols are enabled by manipulation and detection of photonic spectro-temporal degrees of freedom via light–matter interfaces. While present implementations are well suited for high-bandwidth photon sources such as quantum dots, they lack the high resolution required for intrinsically narrowband light–atom interactions. Here, we demonstrate far-field temporal imaging based on ac-Stark spatial spin-wave phase manipulation in a multimode gradient echo memory. We achieve a spectral resolution of 20 kHz with MHz-level bandwidth and an ultralow noise equivalent to 0.023 photons, enabling operation in the single-quantum regime.

中文翻译：

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超窄带几个光子状态的时间成像

通过操纵光子界面的光子光谱时空自由度，可以实现大量的量子信息协议。尽管当前的实现非常适合于诸如量子点之类的高带宽光子源，但它们却缺乏固有的窄带光-原子相互作用所需的高分辨率。在这里，我们演示了在多模式梯度回波存储器中基于ac-Stark空间自旋波相位操纵的远场时间成像。我们实现了20 kHz的光谱分辨率和MHz级带宽，并具有相当于0.023个光子的超低噪声，可在单量子状态下运行。