Collaborative Proposal: Few-Body Interactions in Ultracold Quantum Gases

了解包含许多粒子的系统，即所谓的多体系统，是推动现代研究的一个基本问题，对多个科学和技术领域产生了影响。稀的、超冷的原子蒸汽为集体的、多体现象的研究提供了一个独特的舞台，也为探索一方面是少体动力学和另一方面是多体系统行为之间的关系提供了一个独特的舞台。该项目旨在提高对本质上具有深度量子力学性质且发生在超冷量子气体中的少体系统的许多关键方面的理论理解。这项工作可能产生前所未有的影响，具有深远的科学和技术影响。例如，在复杂系统中调节少体相互作用的能力可能会显著影响化学反应动力学量子控制的可能性。此外，对超冷原子相互作用的深入理解可以在原子钟、量子信息科学和探索许多新的物质相方面产生应用。该项目的一个关键要素是设计计算方法和分析技术，能够比任何其他现有方法更真实地描述超冷少体相互作用。例如，该项目将探索激光场是否可以改变作为多体玻色-爱因斯坦凝聚体一部分的三个或四个附近原子之间的相互作用。中心思想是，每当大集合中的几个原子暂时碰撞时，它们可以作为一个整体吸收或发射辐射。这种共振辐射具有不同的频率，可以通过光谱检测或调谐来改变少体动力学。根据其总体目标，该项目有两个具体目标；发展少体相互作用的相干控制，探索人工规范场产生的奇异相互作用域中新的基本现象。该项目还将建立在最近发现的少体Efimov共振的基础上，以探索Efimov物理与多体超冷系统控制的相关性。这项工作的主要教育影响来自于对研究生和本科生以及博士后研究人员在最先进的理论和计算研究技术方面的培训。

The understanding of how systems containing many particles, so-called many-body systems, behave is a fundamental question driving modern research with impacts across multiple fields of science and technology. Dilute, ultra-cold atomic vapors provide a unique arena for the study of collective, many-body phenomena, and for exploring the relationship between few-body dynamics on the one-hand and the behavior of many-body systems on the other. This project aims at the development of improved theoretical understanding of a number of key aspects of few-body systems that are deeply quantum mechanical in nature and which occur within ultra-cold quantum gases. The work could potentially have unprecedented impact with far-reaching scientific and technological ramifications. For example, the ability to regulate few-body interactions within a complex system could significantly impact the possibilities for quantum control of chemical reaction dynamics. Furthermore, a deep understanding of the ultra-cold atom interactions can spawn applications to atomic clocks, quantum information science, and the exploration of many novel phases of matter. A key element of the project is the design of computational methods and techniques of analysis capable of describing ultra-cold few-body interactions far more realistically than any other existing methodologies. For example, the project will explore whether a laser field can change the interactions among three or four nearby atoms that are part of a many-body Bose-Einstein condensate. The central idea is that whenever a few atoms within the large ensemble temporarily collide, they can absorb or emit radiation as a unit. This resonant radiation has distinct frequencies which can be detected spectroscopically or tuned to alter the few-body dynamics. In accord with its general objective, the project has two specific goals; to develop coherent control of few-body interactions, and to explore new fundamental phenomena in the exotic interaction regime produced by artificial gauge fields. The project will also build on recent discoveries of few-body, Efimov resonances, in order to explore the relevance of Efimov physics to the control of many-body ultra-cold systems. The key educational impact of this work derives from the training of graduate and undergraduate students as well as postdoctoral researchers in state of the art theoretical and computational research techniques.