A Large Bandwidth Room Temperature Single Photon Source

大带宽室温单光子源

• 批准号: 428456730
• 负责人: Dr. Robert Löw
• 金额: --
• 依托单位: Weizmann Institute of Science
• 依托单位国家: 德国
• 项目类别: Priority Programmes
• 财政年份: 2019
• 资助国家: 德国
• 起止时间: 2018-12-31 至 2023-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/428456730?language=en
• 关键词: Large; Bandwidth; Room; Temperature; Single

This project is dedicated to the realization of a single photon source based on strong interactions between Rydberg atoms in a thermal vapour. The possibility to produce anti-bunched photons in a gas of Rubidium atoms has been shown very recently in a proof of principle experiment by the applicants. In this experiment we have shown that, in a micron sized excitation volume, the blockade effect is sufficient to allow for only one Rydberg excitation, which can then be transferred to a light mode in a four-wave mixing scheme. This conversion has to happen within the lifetime of the strongly correlated many body state. In our excitation scheme the coherence time is limited by the motion of the atoms to roughly one nano-second. This means that sufficient strong laser pulses are required to achieve GHz Rabi-frequencies. One of the bottlenecks in our experiment is the small repetition rate (50Hz) of our laser-system. In this proposal we want to realize a second generation of the vapour based single photon source, which will be much closer to real applications. First of all, we will switch to a different four-wave mixing scheme, where we can operate the lasers at rates well above 100kHz giving much better photon statistics. Also parts of the optics will be integrated in the vapour cells as solid immersion lenses. To improve the atom-light coupling, we will also add optical coatings to produce low to medium finesse cavities. This coatings will also include protective coatings to a void chemical reactions. On the material side we will investigate how different Rydberg atoms interact with the close by walls made of Quartz, Sapphire, etc. With the new laser system we will also obtain control over the actual pulse shapes down to the 50ps scale, which will require extended numerical simulations to obtain an optimal sequence. Finally we want to prove the scalability of our approach by realizing two single photon sources in one cell and characterize the indistinguishability of the emitted photons in a Hong-Ou-Mandel interferometer.A notable part of this project will be the cooperation with Dr. Ofer Firstenberg (Weizmann Institute of Science, Israel). His group has broad expertise on Rydberg atoms as well as on the spectroscopy on thermal vapours. As both groups have a strong need for vapour cells featuring optical coatings we will develop together the fabrication of such cells.All these measures will increase the photon rate as well the fidelity of our source. One application would be a purely vapour based quantum repeater scheme, where the wavelength and the bandwidth of the single photon source and of the storage is naturally matched. Another application lies in linear quantum computation or in the creation of more complex photon states (higher Fock states, noon-states,...).

该项目是基于热蒸气中Rydberg原子之间的强相互作用来实现单个光子源的实现。最近，申请人的原理实验证明，在Rubidium原子气体中产生抗堆光子的可能性。在此实验中，我们已经表明，在微米大小的激发体积中，封锁效应足以仅允许一种Rydberg激发，然后可以将其转移到四波混合方案中。这种转换必须在许多身体状态密切相关的一生之内发生。在我们的激发方案中，相干时间受原子的运动限制，大约是纳米秒。这意味着需要足够的强激光脉冲才能实现GHz狂犬病。我们实验中的瓶颈之一是激光系统的重复率（50Hz）。在此提案中，我们希望实现第二代基于蒸气的单光子源，这将更接近实际应用。首先，我们将切换到不同的四波混合方案，在那里我们可以以高于100kHz的速率操作激光器，从而提供更好的光子统计。光学元件的一部分也将作为固体浸入透镜集成在蒸气细胞中。为了改善原子光耦合，我们还将添加光学涂层，以产生低至中等的技巧腔。这种涂层还将包括针对无效化学反应的保护性涂层。在材料方面，我们将研究不同的Rydberg原子如何与石英，蓝宝石等制成的墙壁相互作用。随着新激光系统，我们还将控制对实际脉冲形状，以下到50PS尺度，这将需要扩展数值模拟以获得最佳序列。最后，我们希望通过在一个单元格中实现两个单个光子源来证明我们的方法的可伸缩性，并表征了hong-ou-mandel干涉仪中发射光子的无法区分性。该项目的显着部分将是与Ofer博士的合作。 Firstenberg（以色列魏兹曼科学学院）。他的小组在Rydberg原子以及热蒸气的光谱学方面具有广泛的专业知识。由于两组都非常需要具有光学涂层的蒸气单元，因此我们将共同开发这种细胞的制造。所有这些措施都会提高光子速率，以及我们来源的忠诚度。一种应用将是纯粹基于蒸气的量子中继器方案，其中单个光子源的波长和带宽自然匹配。另一个应用在于线性量子计算或创建更复杂的光子状态（较高的Fock状态，中午状态，...）。