Long-range interaction using strontium atoms in an optical lattice

量子传感器提供了前所未有的精确度和准确度，在大多数情况下都超过了它们的经典对应物。例如，光学钟已经达到了前所未有的精度~1*10-18，这是使用传统机械振荡器无法想象的。背后的基本想法是关于原子的捕获和冷却到超低温。现在，重点是将这些经过验证的概念转化为紧凑、坚固和节能的传感器，并将其应用于现实世界。这种阶跃变化需要一个有效的、控制良好的原子源和最佳的检测技术。在我们的实验室里，我们通常会将数百万个锶原子冷却到微开尔文温度。原子散粒噪声是这些量子传感器实现最终精度的根本障碍之一。在我们的实验中，我们的目标是利用3P0-3D1跃迁来在不同晶格位置的锶原子之间建立纠缠[1]。这种纠缠是由较大的感生偶极矩(&gt；3.5Deye)引起的。将N原子纠缠将使原子传感器的精度提高1/2。在这个项目中，探测技术将起到至关重要的作用。因此，我们会探讨如何落实各项侦测计划。除了测量不同状态下的相对粒子数和空间分辨率在几个微米量级的原位荧光测量外，我们还将研究利用光在光学晶格中的原子上的布拉格散射作为识别小尺度周期结构的手段。我们还将研究飞行时间成像技术，以确定样本动量分布的模式。事实上，噪声相关方法对于识别晶格中的相位也是非常有用的。在该项目中，将有机会获得真空室、激光、光学接口和计算机控制方面的经验和专业知识。

Quantum sensors provide unprecedented precision & accuracy, and are surpassing their classical counter parts in most of the cases. For instance, optical clocks have already reached the unprecedented precision ~1*10-18, which is unthinkable using conventional mechanical oscillators. The underpinning idea behind is about trapping and cooling of atoms to ultra low temperatures. Now thrust is on to translating these proven concepts into compact, robust and energy efficient sensors with real world applications. Such a step change demands an efficient and well-controlled atom source and optimal detection techniques. In our lab, we routinely cool millions of Sr atoms to micro Kelvin temperature. Atom shot noise is one of the fundamental barriers to an ultimate achievable precision in these quantum sensors. In our experiment, we aim to use the 3P0-3D1 transition in order to create entanglement between Sr atoms at different lattice sites [1]. This entanglement is caused by a large induced dipole moment (>3.5Debye). Entangling N atoms will increase the precision of an atomic sensor by factor of sqrt N. In this project, detection techniques will play a crucial role. Therefore, we will explore the implementation of various detection schemes. In addition to measurements of the relative particle numbers in different states and 'in-situ' fluorescence measurements with spatial resolution on the order of a few micro, we will study the use of Bragg-scattering of light on the atoms in the optical lattice as a means to identify small-scale periodic structures. We will also study time-of-flight imaging techniques to identify patterns in the momentum distribution of the sample. In fact, noise correlation methods are also very useful to identify the phases in a lattice. Within the project, there will be an opportunity to gain experience and expertise on vacuum chamber, lasers, optical-interface and computer control.