Quantum state resolved few-body collisions and reactions at ultralow temperatures

量子态解决了超低温下的少体碰撞和反应

• 批准号: 399903135
• 负责人: Professor Dr. Johannes Hecker Denschlag
• 金额: --
• 依托单位: Institut für Quantenmaterie
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2018
• 资助国家: 德国
• 起止时间: 2017-12-31 至 2022-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/399903135?language=en
• 关键词: Quantum; state; resolved; few; body

While three- and four-body collisions of atoms are some of the most fundamental processes in nature, they are still not fully understood. In order to answer some of the important, open questions, we propose here to experimentally investigate such few-body collisions in the ultracold regime in a fully state-resolved manner. Using ultracold 87Rb atoms and 87Rb2 molecules we prepare an initial quantum state of colliding particles and after the collision we measure the quantum states of the diatomic products. For this, we will employ and further develop a highly selective detection method that our group has recently discovered. It is based on resonance-enhanced multi-photon ionization of molecules and an efficient subsequent ion detection. We will study two different kinds of collisional processes: 1) Three-body recombination of 87Rb where a Rb2 molecule is formed. 2) Relaxation of an excited ultracold Rb2 molecule to a more deeply bound state in a collision with either a Rb atom or another Rb2 molecule. Our experiments tackle the novel research field of ultracold chemistry which only recently has become accessible. Therefore we expect our research to deliver a large number of new insights. Besides gaining a fundamental understanding of ultracold reactive or inelastic few-body collisions, an important incentive for our work is to learn how to gain control over chemical reactions. We expect that the proposed experiments will lead the young field of cold state-to-state chemistry, in particular for systems with many reaction paths.

虽然原子的三体和四体碰撞是自然界中一些最基本的过程，但它们仍然没有被完全理解。为了回答一些重要的、悬而未决的问题，我们在这里建议以完全状态解析的方式对超冷状态下的此类少体碰撞进行实验研究。使用超冷 87Rb 原子和 87Rb2 分子，我们准备了碰撞粒子的初始量子态，并在碰撞后测量双原子产物的量子态。为此，我们将采用并进一步开发我们小组最近发现的一种高选择性检测方法。它基于分子的共振增强多光子电离和高效的后续离子检测。我们将研究两种不同类型的碰撞过程：1）87Rb的三体重组，形成Rb2分子。 2) 激发的超冷 Rb2 分子在与 Rb 原子或另一个 Rb2 分子碰撞时弛豫至更深的束缚态。我们的实验涉及最近才变得可行的超冷化学新研究领域。因此，我们期望我们的研究能够提供大量新见解。除了对超冷反应或非弹性少体碰撞有基本的了解外，我们工作的一个重要动机是学习如何控制化学反应。我们预计所提出的实验将引领冷态间化学的年轻领域，特别是对于具有许多反应路径的系统。