Dideriksen Karsten B, Schmieg Rebecca, Zugenmaier Michael, Polzik Eugene S
Niels Bohr Institute, University of Copenhagen, Copenhagen Ø, Denmark.
Nat Commun. 2021 Jun 17;12(1):3699. doi: 10.1038/s41467-021-24033-8.
Non-classical photon sources are a crucial resource for distributed quantum networks. Photons generated from matter systems with memory capability are particularly promising, as they can be integrated into a network where each source is used on-demand. Among all kinds of solid state and atomic quantum memories, room-temperature atomic vapours are especially attractive due to their robustness and potential scalability. To-date room-temperature photon sources have been limited either in their memory time or the purity of the photonic state. Here we demonstrate a single-photon source based on room-temperature memory. Following heralded loading of the memory, a single photon is retrieved from it after a variable storage time. The single-photon character of the retrieved field is validated by the strong suppression of the two-photon component with antibunching as low as [Formula: see text]. Non-classical correlations between the heralding and the retrieved photons are maintained for up to [Formula: see text], more than two orders of magnitude longer than previously demonstrated with other room-temperature systems. Correlations sufficient for violating Bell inequalities exist for up to τ = (0.15 ± 0.03) ms.
非经典光子源是分布式量子网络的关键资源。由具有记忆能力的物质系统产生的光子尤其具有前景，因为它们能够被集成到一个可按需使用每个源的网络中。在各类固态和原子量子存储器中，室温原子蒸气因其稳健性和潜在的可扩展性而格外引人注目。迄今为止，室温光子源在其存储时间或光子态的纯度方面都受到限制。在此，我们展示了一种基于室温存储器的单光子源。在对存储器进行预示加载之后，经过可变的存储时间，从中检索出一个单光子。通过将双光子成分强烈抑制至反聚束低至[公式：见正文]，验证了检索到的场的单光子特性。预示光子与检索到的光子之间的非经典关联可维持长达[公式：见正文]，比此前在其他室温系统中所展示的时长多出两个数量级以上。对于长达τ = (0.15 ± 0.03) ms，存在足以违反贝尔不等式的关联。
