Theory of ultracold matter

超冷物质理论

• 批准号: 722-2007
• 负责人: Zaremba, Eugene
• 金额: $ 3.28万
• 依托单位: Queen's University
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2007
• 资助国家: 加拿大
• 起止时间: 2007-01-01 至 2008-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=366006
• 关键词: Theory; ultracold; matter

This proposal concerns the subject of Bose-Einstein condensation (BEC) in trapped Bose gases. At ultra-low temperatures, a gas of bosonic atoms exhibits a kind of condensation in which most of the atoms fall into the lowest available quantum state. In this novel state of matter, the atoms act coherently, and exhibit quantum behaviour on scales approaching macroscopic dimensions. The implications are far-reaching and profound. Potential applications include atomic lasers, atomic lithography and quantum computing.     The proposed research can be broadly characterized as the theoretical study of the dynamics of these trapped gases at finite temperatures. Above absolute zero, the gas consists of a combination of the condensed phase, the condensate, and thermally excited atoms that constitute a thermal cloud. This system of atoms can undergo a variety of modes of oscillation that can be studied experimentally. The theoretical challenge is to provide a description of this behaviour that explains the observed mode frequencies and the rate at which the modes decay as a function of time.     Much of the interest in the subject stems from the fact that trapped gases can be manipulated in various ways. For example, the gas can be made to spin rapidly by rotating the confining potential. In this way, arrays of vortices can be generated. Part of the project will address the question of how these vortices are initially formed, and how the vortices finally arrange themselves in an ordered array.     Another way to manipulate the atoms is to simply shine light on them. If the light forms a standing wave, a periodic potential arises and the atoms effectively reside on a lattice. The theoretical tools we have at our disposal will allow us to explore the interesting dynamical behaviour of the atoms in this situation, especially at elevated temperatures when both a condensate and thermal cloud are present. The knowledge gained from such studies will extend even further our ability control atoms in these kinds of systems.

这一提议涉及玻色-爱因斯坦凝聚（BEC）在困住玻色气体中的主题。在超低温下，玻色子原子气体表现出一种凝结，其中大多数原子落入最低可用量子态。在这种物质的新状态下，原子的行为是一致的，并在接近宏观维度的尺度上表现出量子行为。其影响是深远的。潜在的应用包括原子激光、原子光刻和量子计算。所提出的研究可以广泛地描述为这些被困气体在有限温度下的动力学的理论研究。在绝对零度以上，气体由凝聚相、冷凝物和热激发原子组成，这些原子构成热云。这个原子系统可以经历各种各样的振荡模式，这些振荡模式可以通过实验来研究。理论上的挑战是提供对这种行为的描述，以解释观察到的模式频率和模式随时间衰减的速率。人们对这门学科的兴趣很大程度上源于这样一个事实，即捕获的气体可以用各种方式加以操纵。例如，可以通过旋转围势使气体快速旋转。通过这种方式，可以生成漩涡阵列。该项目的一部分将解决这些漩涡最初是如何形成的问题，以及这些漩涡最终是如何排列成有序数组的。另一种操纵原子的方法是简单地用光照射它们。如果光形成驻波，就会产生周期势，原子就会有效地驻留在晶格上。我们所掌握的理论工具将使我们能够探索这种情况下原子的有趣的动力学行为，特别是在高温下，当冷凝物和热云同时存在时。从这些研究中获得的知识将进一步扩展我们在这类系统中控制原子的能力。