ICFO-Institut de Ciencies Fotoniques, The Barcelona Institute of Science and Technology, 08860 Castelldefels, Barcelona, Spain.
Department of Physics, University of Basel, Klingelbergstrasse 82, 4056 Basel, Switzerland.
Nat Commun. 2016 Nov 25;7:13556. doi: 10.1038/ncomms13556.
The generation of ultra-narrowband, pure and storable single photons with widely tunable wave shape is an enabling step toward hybrid quantum networks requiring interconnection of remote disparate quantum systems. It allows interaction of quantum light with several material systems, including photonic quantum memories, single trapped ions and opto-mechanical systems. Previous approaches have offered a limited tuning range of the photon duration of at most one order of magnitude. Here we report on a heralded single photon source with controllable emission time based on a cold atomic ensemble, which can generate photons with temporal durations varying over three orders of magnitude up to 10 μs without a significant change of the readout efficiency. We prove the nonclassicality of the emitted photons, show that they are emitted in a pure state, and demonstrate that ultra-long photons with nonstandard wave shape can be generated, which are ideally suited for several quantum information tasks.
生成超窄带、纯且可存储的单光子，其波形具有广泛的可调谐性，这是朝着需要远程离散量子系统互联的混合量子网络迈出的重要一步。它允许量子光与多个物质系统相互作用，包括光子量子存储器、单个囚禁离子和光机械系统。以前的方法提供了光子持续时间的可调谐范围最大只有一个数量级。在这里，我们报告了一种基于冷原子集合的可控制发光时间的被探测单光子源，它可以在不显著改变读出效率的情况下，产生持续时间在三个数量级内变化至 10 μs 的光子。我们证明了所发射光子的非经典特性，表明它们是以纯态发射的，并证明可以产生具有非标准波形的超长光子，这些光子非常适合于几种量子信息任务。
