compact Cold-Atom Sources (cCAS)

紧凑型冷原子源 (cCAS)

基本信息

批准号：
EP/R001685/1
负责人：
Christopher Foot
金额：
$ 25.04万
依托单位：
University of Oxford
依托单位国家：
英国
项目类别：
Research Grant
财政年份：
2017
资助国家：
英国
起止时间：
2017 至无数据
项目状态：
已结题

来源：
https://gtr.ukri.org/projects?ref=EP%2FR001685%2F1
关键词：
compact Cold Atom Sources cCAS

项目摘要

We shall develop compact cold-atom sources for the alkali metals rubidium, caesium and potassium; and for the alkaline-earth metal strontium (Sr). These are very suitable for a range of applications in quantum technology and a components in the construction of apparatus for scientific research more broadly. Magneto-optical traps (MOTs) can capture slow atoms directly from an atomic vapour at room temperature to provide a very convenient source of cold atoms. We have used an arrangement of four triangular mirrors arranged as a pyramid inside the vacuum region to make a MOT in three separate experiments over the years. Recently we developed an improved design that is more compact and adjustable than other sources. A patent application covering the innovative features of this pyramid-MOT was applied for in April 2016 and we are constructing a prototype working with rubidium (Rb). We will develop this into a commercial product integrated with a laser system produced by M Squared Lasers (MSL). The company's titanium-doped sapphire lasers provide a high power, relative to other tuneable lasers, and unmatched stability. We shall make full use of the available laser power by tailoring the size of the mirrors and enclosing vacuum chamber to produce a high flux of atoms. This will a give strong signals and high repetition rate of measurements in instruments such as atomic interferometers which as the basis of the quantum technology used in gravimeters, gyroscopes etc. This device can laser cool the other alkali metal atoms Cs and K, and light at all the wavelengths required is available from MSL. Compact and reliable cold-atom sources are of themselves a useful device that can be sold in the scientific equipment market that constitutes much of MSL's present sales. While working on compact cold-atom sources we have noted the rapidly increasing interest in using cold strontium atoms for optical-lattice clocks, matter-wave interferometers and experiments with ultracold quantum gases. Strontium has intrinsic advantages such as rapid laser cooling, insensitivity to external magnetic fields and, for some isotopes, inter-atomic collisions are almost negligible. However working with cold Sr atoms much more technically demanding than Rb. In the traditional approach to laser cooling this species Sr atoms pass along the axis of a tapered solenoid (so-called Zeeman slowing developed in the 1980s) and many more laser wavelengths are required than for an alkali metals (Rb etc.) - up to 6 wavelengths for a Sr optical-lattice clock. However the availability of reliable lasers (from MSL) will make it possible to use Sr in products in the short term (within 5 years). Reportedly there have been attempts to make more compact sources of cold Sr using approaches similar to those for Rb but, for reasons explained in the proposal, a different method is more feasible. Our approach combines aspect of Zeeman slowing with long magnets with the compactness of in-vacuum mirrors (as in our pyramid design). In a further step we can develop this into a pulsed source that allows rapid loading of a high number of atoms (e.g. in 0.01 s) but with a much reduced flux of atoms during the measurement period (e.g. 1 s for some clocks). This mode of operation, with a pulsed valve, conserves atoms so that the oven does not need frequent reloading which is inconvenient especially for a field-deployed interferometer. The team in Oxford are not using Sr (although the PI has in the past) but the expertise is available to build the novel design (with features that we can patent, as in the work on Rb). The optimum outcome would provide a competitive edge for a product manufactured by MSLs. Licensing, or other, will be managed through Oxford University Innovation Ltd (as for the cold-atom source of Rb) to protect the technology and ensure that it remains part of a UK-based industry.

开发碱金属铷、铯、钾的致密冷原子源；以及碱土金属锶（Sr）。这些非常适合量子技术的一系列应用以及更广泛的科学研究设备的构建组件。磁光陷阱（MOT）可以在室温下直接从原子蒸气中捕获慢速原子，以提供非常方便的冷原子源。多年来，我们在三个独立的实验中使用了在真空区域内以金字塔形式排列的四个三角镜的排列来制作 MOT。最近，我们开发了一种改进的设计，比其他来源更紧凑且可调节。 2016 年 4 月申请了涵盖该金字塔 MOT 创新功能的专利申请，我们正在构建一个使用铷 (Rb) 的原型。我们将把它开发成与 M Squared Lasers (MSL) 生产的激光系统集成的商业产品。该公司的掺钛蓝宝石激光器提供了相对于其他可调谐激光器的高功率以及无与伦比的稳定性。我们将通过定制镜子的尺寸和封闭真空室来充分利用可用的激光功率，以产生高通量的原子。这将为原子干涉仪等仪器提供强信号和高重复率的测量，原子干涉仪是重力计、陀螺仪等中使用的量子技术的基础。该设备可以激光冷却其他碱金属原子 Cs 和 K，并在MSL 提供所有所需的波长。紧凑且可靠的冷原子源本身就是一种有用的设备，可以在科学设备市场上销售，而科学设备市场构成了 MSL 目前的大部分销售额。在研究紧凑型冷原子源时，我们注意到人们对使用冷锶原子用于光学晶格钟、物质波干涉仪和超冷量子气体实验的兴趣迅速增加。锶具有固有的优势，例如快速激光冷却、对外部磁场不敏感，并且对于某些同位素来说，原子间碰撞几乎可以忽略不计。然而，使用冷的锶原子比铷原子的技术要求更高。在传统的激光冷却方法中，这种物质 Sr 原子沿着锥形螺线管的轴穿过（20 世纪 80 年代开发的所谓塞曼减速），并且需要比碱金属（Rb 等）更多的激光波长 - 高达Sr 光晶格时钟有 6 个波长。然而，可靠的激光器（来自 MSL）的可用性将使短期（5 年内）在产品中使用 Sr 成为可能。据报道，有人尝试使用与 Rb 类似的方法来制造更紧凑的冷 Sr 源，但由于提案中解释的原因，不同的方法更为可行。我们的方法将塞曼减速与长磁铁的方面与真空镜的紧凑性结合起来（如我们的金字塔设计）。下一步，我们可以将其开发为脉冲源，允许快速加载大量原子（例如在 0.01 秒内），但在测量期间原子通量大大减少（例如某些时钟为 1 秒）。这种使用脉冲阀的操作模式可以节省原子，因此炉子不需要频繁重新装载，这对于现场部署的干涉仪来说尤其不方便。牛津的团队没有使用 Sr（尽管 PI 过去曾使用过），但可以利用专业知识来构建新颖的设计（具有我们可以申请专利的功能，如 Rb 的工作）。最佳结果将为 MSL 制造的产品提供竞争优势。许可或其他方面将通过牛津大学创新有限公司（就铷冷原子源而言）进行管理，以保护该技术并确保其仍然是英国行业的一部分。