RUI: Photoassociation Studies in Rare-Gas Atom Traps

利用实验和计算模型研究了氪和/或氩原子在磁光阱中的光缔合作用。 研究小组有能力区分单激发态和双激发态分子的动力学效应。他们的努力已经导致在氪中发现了一类不寻常的双激发纯长程态。他们正在进行的工作重点是表征氩的PA光谱的三个不同范围，特别是在811.5 nm（冷却过渡），801.5 nm（淬火过渡）和912.3 nm（另一种淬火过渡）附近。的主要目标是，看看是否可以占在两个陷阱的损失机制，即潘宁电离和辐射淬灭之间的权衡的光谱之间的差异。 该建议的智力价值在于仍然可以了解超冷稀有气体中的PA过程，偶极-偶极相互作用和碰撞动力学。 虽然关于稀有气体原子阱中碰撞机制的问题多年来一直模糊不清，而且在很大程度上没有答案，但这项工作向前迈出了一步，将实验光谱中看到的特征与解释模型的一部分特定效应联系起来。这种效应的例子包括：形成纯长程分子态，由于大的弗兰克-康登因子而增强双激发速率，以及潘宁电离和辐射淬灭之间的共振权衡。本课题的研究团队通过对课题的理论和实验两方面的研究，能够在还有很多需要学习的领域取得重大进展。本课题涉及具有两种广泛影响的基础研究。 所研究的特定系统是由一对原子组成的一种不寻常的分子。 这个系统的不寻常之处在于，原子可以彼此相距极远，但却被一种非常长距离的电力结合在一起。 由力产生的化学键实际上非常微弱（想象一个蜘蛛网将两个相距1米的高尔夫球连接在一起），因此如果键不被打破，原子必须非常缓慢地移动。 像这样的弱长程力与新兴的量子信息技术领域有关，这需要实验人员理解和控制分离良好的原子之间的相互作用。 因此，这个项目的第一个关键影响是发展了关于这些力以及由它们产生的原子-原子相互作用的详细科学知识。 二是通过实践研究经验培养本科生。 这些学生在与该项目的首席研究员一起工作时学习重要技能，首席研究员在激光，光学，电子，真空技术，计算技术以及理论量子物理学方面具有专业知识。

Experiments and computational models are used in studies of photoassociation (PA) of krypton and/or argon atoms in a magneto-optical trap. The research team has the ability to distinguish between the dynamical effects of singly and doubly excited molecular states. Their efforts have already led to the discovery of an unusual class of doubly excited, purely long-range states in krypton. Their ongoing work focuses on characterizing three different ranges of the PA spectrum of argon, specifically near 811.5 nm (the cooling transition), 801.5 nm (a quench transition), and 912.3 nm (another quench transition). The main goal is to see whether differences among the spectra can be accounted for in terms of a tradeoff between two trap loss mechanisms, namely Penning ionization and radiative quenching. The intellectual merit of the proposal lies in what can still be learned about PA processes, dipole-dipole interactions, and collision dynamics in ultracold rare gases. While questions about collision mechanisms in rare-gas atom traps have remained vague and largely unanswered for many years, this work takes a step forward by associating features seen in experimental spectra with specific effects that are part of an explanatory model. Examples of such effects include: the formation of purely long-range molecular states, the enhancement of double-excitation rates due to large Franck-Condon factors, and resonant tradeoffs between Penning ionization and radiative quenching. By covering both theoretical and experimental sides of the project, the research team is in a position to make significant progress in an area where there is still much to learn.This project involves basic research that promises two kinds of broader impact. The specific system under examination is an unusual kind of molecule composed of a single pair of atoms. What makes the system unusual is that the atoms can be extremely distant from each other while nevertheless being held together by a very long-range electrical force. The chemical bond produced by the force is actually very feeble (imagine a spider web holding together two golf balls that are 1 meter apart), so the atoms have to be moving very slowly if the bond is not to be broken. Weak, long-range forces like this are relevant in the emerging field of quantum information technology, which requires experimenters to understand and control interactions between well-separated atoms. So the first key impact of this project is the development of detailed scientific knowledge about these forces and the atom-atom interactions that result from them. The second is the training of undergraduate students through hands-on research experience. These students learn vital skills while working alongside the project's Principal Investigator, who has expertise in lasers, optics, electronics, vacuum technology, computational techniques, as well as theoretical quantum physics.