Spin transport phenomena in ultracold atomic gases

超冷原子气体中的自旋输运现象

• 批准号: RGPIN-2017-03893
• 负责人: McGuirk, Jeffrey
• 金额: $ 1.53万
• 依托单位: Simon Fraser University
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2022
• 资助国家: 加拿大
• 起止时间: 2022-01-01 至 2023-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=762537
• 关键词: Spin; transport; phenomena; ultracold; atomic

Understanding the flow of particles such as transport of electrons is vital in designing and creating devices. As electronics become smaller and smaller, classical physics ceases to describe transport, and quantum mechanics becomes important. Additionally, next-generation devices make use of not just electric properties of materials, but also magnetic properties to form versatile circuit elements, such as computer memory. The flow of particles with magnetic properties, known as "spin" at the microscopic quantum level, forms the field of spin transport. I propose a program to explore spin transport in an ultracold gas. This proposal seeks to study the roles of magnetic (spin) orientation, dimensionality, and confinement geometry on spin transport in an atomic gas cooled to near absolute zero, where the crossover from classical to quantum transport behavior can be observed. A detailed understanding of spin transport is necessary for many applications, including development of devices that use atoms to carry and process information ("atomtronic" devices), spin-based sensor technology, and understanding out-of-equilibrium dynamics in the quantum regime. More fundamentally, spin transport can demonstrate how microscopic interactions lead to macroscopic dissipative and coherent effects. Subtle properties of individual two-atom interactions can lead to dramatically different behavior in bulk ensembles. Understanding these microscopic-macroscopic connections is a key goal in spin transport studies. Ultracold atomic gases are well suited to exploring spin dynamics in a controllable and precise way and, through comparisons with other systems, allow for tests of theoretical models. Linking seemingly disparate physical systems with similar theoretical descriptions is a powerful tool for testing theories and determining their critical components. Thus, studies of ultracold gases can both benefit from, as well as inform and enrich, studies in other fields. My approach to studying spin transport uses ultracold Rubidium atoms at the classical-quantum crossover. We will leverage our previous work using optical patterning techniques to create novel spin structures and confinement geometries, including sharp gradients in magnetization (spin), two-dimensional geometries, and corrugated confinement geometries. We will extend these techniques to explore diffusion, excitations, and coherence in new regimes, and couple spin currents to other phenomena like vibrations or thermal gradients. The impact of the proposed research program will be to contribute to a comprehensive understanding of quantum spin transport, which informs next-generation atom-based devices. It will also provide a high quality training environment for students, where they learn a broad array of experimental, analytical, and computational techniques as they train in cutting-edge quantum technology.

了解粒子的流动（例如电子的传输）对于设计和制造设备至关重要。随着电子产品变得越来越小，经典物理学不再描述传输，量子力学变得重要。此外，下一代设备不仅利用材料的电特性，还利用磁特性来形成通用电路元件，例如计算机存储器。具有磁性的粒子的流动，在微观量子水平上被称为“自旋”，形成自旋输运场。 我提出了一个探索超冷气体中自旋输运的计划。该提案旨在研究冷却至接近绝对零的原子气体中磁（自旋）取向、维度和约束几何对自旋输运的作用，其中可以观察到从经典输运行为到量子输运行为的交叉。 对自旋输运的详细了解对于许多应用都是必要的，包括开发使用原子携带和处理信息的设备（“原子电子”设备）、基于自旋的传感器技术以及了解量子体系中的非平衡动力学。更根本的是，自旋输运可以证明微观相互作用如何导致宏观耗散和相干效应。单个两个原子相互作用的微妙特性可能导致整体系综中显着不同的行为。了解这些微观与宏观的联系是自旋输运研究的一个关键目标。 超冷原子气体非常适合以可控且精确的方式探索自旋动力学，并且通过与其他系统的比较，可以测试理论模型。将看似不同的物理系统与相似的理论描述联系起来是测试理论和确定其关键组成部分的强大工具。因此，超冷气体的研究既可以受益于其他领域的研究，也可以为其他领域的研究提供信息和丰富。 我研究自旋输运的方法是使用经典量子交叉处的超冷铷原子。我们将利用我们之前的工作，使用光学图案化技术来创建新颖的自旋结构和限制几何形状，包括磁化强度（自旋）的锐梯度、二维几何形状和波纹限制几何形状。我们将扩展这些技术来探索新机制中的扩散、激发和相干性，并将自旋电流与振动或热梯度等其他现象耦合起来。拟议研究计划的影响将有助于全面了解量子自旋输运，从而为下一代基于原子的设备提供信息。它还将为学生提供高质量的培训环境，让他们在接受尖端量子技术培训时学习广泛的实验、分析和计算技术。