Rydberg atoms in confined geometries - Experiment and Theory

对内部和外部原子度的控制已经达到了比固态器件更精确的技术应用水平。最突出的例子是铯原子钟，它为整个地球设定了时间基准。结合光速的定义，它也是米的起源；因此，空间和时间的测量是以控制原子为基础的。原子还可以作为磁场、电场和电磁场、引力、加速度和旋转的敏感探针。当增加原子气体产生、延迟、存储和修改光场的能力时，很明显，更多的基于原子的设备将进入我们的日常生活。Symmetricom的芯片级原子钟（CSAC）是一个里程碑，其中所有组件都已小型化，使其可集成并与当前工业技术兼容。然而，小型化有时也会成为一种负担，因为更近的限制壁更有可能以不希望的方式与原子相互作用。在这个提议中要回答的科学问题一方面是如何最小化原子与附近表面的耦合，另一方面是如何积极地利用表面来调解（里德伯）原子之间的相互作用。这里要讨论的主要问题是铯原子与介电材料的相互作用。原子的光激发能级将包括低能级和高激发的里德伯态。实验将在室温下用热原子进行。我们对介电材料的选择主要是由器件应用驱动的。我们最感兴趣的是石英玻璃，这是蒸汽电池的标准材料。对于我们的研究来说，特别重要的材料是金刚石，因为在红外和远红外中没有光激发满足了里德伯原子的需要，里德伯原子在这个波长范围内表现出强烈的偶极子跃迁。在进一步的处理步骤中，我们可以通过调整材料特性（如材料厚度、层的排列等）来改变固体中的激发光谱，从而抑制或增强原子-壁耦合。后者可能有利于所有依赖于光饱和的效应，通过增加光散射率，在大多数传感应用中不需要或至少需要精确的耦合知识。该提案汇集了斯图加特和罗斯托克大学的两个团队，他们在实验里德堡物理（斯图加特）和理论原子表面物理（罗斯托克）方面拥有世界领先的专业知识。双方的共同努力有望对受限几何结构中原子的相干操纵产生新的见解。

The control over the internal and external degrees of atoms has reached a level of precision that allows for technical applications superior to solid state devices. The most prominent example is the cesium atom clock, which sets the time reference for the entire planet. In combination with the definition of the speed of light it is also the origin of the meter; thus the measurement of space and time is based on controlling atoms. Atoms can further serve as sensitive probes for magnetic, electric and electromagnetic fields, gravitation, acceleration and rotation. When adding the capability of atomic gases to generate, delay, store and modify light fields, it becomes evident that many more atom-based devices are set to enter our everyday life. A landmark is set by the chip scale atomic clock (CSAC) by Symmetricom, in which all components have been miniaturized to make it integrable and compatible with current technologies present in industry. However, miniaturization can sometimes also be a burden, given that much closer confining walls are more likely to interact with the atoms in an unwanted way.The scientific questions to be answered in this proposal are on the one hand how to minimise the coupling of atoms to a nearby surface, and on the other hand the active use of the surface to mediate interactions between (Rydberg) atoms. The main topic to be addressed here are the interactions of cesium atoms with dielectric materials. The level of optical excitation of the atoms will cover low-lying states as well as highly excited Rydberg states. The experiments will work with thermal atoms at room temperature. Our choice of dielectric materials is mainly driven by device applications. We are mostly interested in quartz glass, which is the standard material for vapour cells. An especially important material for our investigations is diamond, as the absence of optical excitations in the infrared and far-infrared meets the needs of Rydberg atoms, which exhibit strong dipole transitions in this range of wavelengths.In a further processing step we can alter the spectra of excitations in the solid by tailoring material properties such as material thickness, arrangement of layers etc. to either suppress or enhance the atom-wall coupling. The latter might be beneficial for all effects relying on optical saturation by increasing the light scattering rate where the absence or at least the accurate knowledge of the coupling is desirable for most sensing applications.The proposal brings together two groups at the Universities of Stuttgart and Rostock with world-leading expertise in experimental Rydberg physics (Stuttgart) and theoretical atom-surface physics (Rostock). The combined effort promises to yield new insights into coherent manipulation of atoms in confined geometries.