RUI: Topological Excitations in Spinor Bose-Einstein Condensates

RUI：旋量玻色-爱因斯坦凝聚中的拓扑激发

• 批准号: 1806318
• 负责人: David Hall
• 金额: $ 51万
• 依托单位: Amherst College
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2018
• 资助国家: 美国
• 起止时间: 2018-07-01 至 2022-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1806318&HistoricalAwards=false
• 关键词: RUI; Topological; Excitations; Spinor; Bose

Humans have long had a fascination with symmetry, a concept familiar to anyone who has glanced in a mirror or contemplated their left and right hands. Indeed, symmetry is a fundamental organizing principle that appears in every scientific discipline. In physics, symmetries often manifest themselves in terms of topology, or the study of how shapes and structures may - or may not - be deformed continuously into one another. Topology has recently emerged as an important and increasingly relevant topic in modern physics, as recognized by the 2016 Nobel Prize. Shared topological features in different physical systems permit complementary studies, even when those systems are extremely different. For example, similar physics can be studied both in giant particle accelerators at the highest energies and in tabletop apparatus at the coldest temperatures. The ultracold environment central to this research is a dilute gas cooled to tens of billionths of a degree above absolute zero, at which point it develops properties that make it into a kind of well-controlled "universe" into which may be summoned analogues of particles that might - or, perhaps more interestingly, might not - appear in the "real" universe. This project will study the creation and time-evolution of these particle-like phenomena, including point-like monopoles and extended particles known as "skyrmions" and "knots." Such experiments can provide insight into the phenomena and behavior of many different topological systems, and contribute to emerging technologies based on their manipulation and control. The scientific program will also enhance the relationship between cutting-edge experimental research and undergraduate education by providing technological and scientific training opportunities for several highly motivated undergraduates, as well as for a graduate student researcher. In these ways it contributes to the education of the next generation of citizen-scientists.Particle-like topological structures are ubiquitous in physics, appearing in cosmology, particle physics, and condensed-matter physics, among others. They can exhibit a surprising degree of persistence, as they are characterized by a conserved topological charge. Superfluids, such as dilute-gas Bose-Einstein condensates, provide new and exciting opportunities to examine these excitations in highly-controlled environments. The underlying symmetries (and magnetic phases) of a superfluid determine what kinds of topological excitations it can support. This experimental research program examines three-dimensional topological excitations within spin-1 and spin-2 Bose-Einstein condensates, including monopoles, knots, and skyrmions. The spin-1 experiments will explore the time evolution of the excitations following their creation. The spin-2 experiments will begin by creating and exploring the topological excitations permitted by the wider variety of available magnetic phases, and answer similar questions about their time-evolution. The excitations will be created by exposing the condensate to time-dependent magnetic and optical fields, and will be subsequently characterized by close examination of the superfluid using established imaging techniques. The results are expected to contribute directly to our scientific understanding of topological excitations across the many branches of physics in which they appear. The scientific program will also enhance the relationship between cutting-edge experimental research and undergraduate education by providing technological and scientific training opportunities for several highly motivated undergraduates, as well as for a graduate student researcher.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

人类长期以来对对称性着迷，任何照过镜子或观察过自己左右手的人都熟悉这一概念。事实上，对称性是每个科学学科中都出现的基本组织原则。在物理学中，对称性通常以拓扑学的形式表现出来，或者研究形状和结构如何或不可以连续地相互变形。正如 2016 年诺贝尔奖所认可的那样，拓扑学最近已成为现代物理学中一个重要且日益相关的主题。不同物理系统中共享的拓扑特征允许互补研究，即使这些系统极其不同。例如，可以在最高能量的巨型粒子加速器和最冷温度的桌面设备中研究类似的物理现象。这项研究的核心超冷环境是一种冷却到绝对零以上几十亿分之一度的稀气体，此时它发展出的特性使其成为一种受良好控制的“宇宙”，可以在其中召唤粒子的类似物这可能——或者更有趣的是，可能不会——出现在“真实”的宇宙中。该项目将研究这些类粒子现象的产生和时间演化，包括点状单极子和被称为“斯格明子”和“结”的扩展粒子。此类实验可以深入了解许多不同拓扑系统的现象和行为，并有助于基于其操纵和控制的新兴技术。该科学项目还将通过为几名积极进取的本科生以及研究生研究员提供技术和科学培训机会，加强前沿实验研究和本科生教育之间的关系。通过这些方式，它有助于下一代公民科学家的教育。类粒子拓扑结构在物理学中无处不在，出现在宇宙学、粒子物理学和凝聚态物理学等领域。它们可以表现出令人惊讶的持久性，因为它们的特点是保守的拓扑电荷。超流体，例如稀气体玻色-爱因斯坦凝聚态，为在高度控制的环境中检查这些激发提供了新的、令人兴奋的机会。超流体的基本对称性（和磁相）决定了它可以支持哪种拓扑激发。该实验研究项目检查了自旋 1 和自旋 2 玻色-爱因斯坦凝聚体中的三维拓扑激发，包括单极子、结和斯格明子。 spin-1 实验将探索激发产生后的时间演化。 spin-2 实验将从创建和探索更广泛的可用磁相允许的拓扑激发开始，并回答有关其时间演化的类似问题。通过将凝聚物暴露于随时间变化的磁场和光场来产生激发，并随后使用已建立的成像技术对超流体进行仔细检查来表征。这些结果预计将直接有助于我们对拓扑激发的科学理解，跨越它们出现的许多物理学分支。该科学项目还将通过为几名积极进取的本科生以及研究生研究人员提供技术和科学培训机会，加强前沿实验研究与本科生教育之间的关系。该奖项反映了 NSF 的法定使命，并被认为是值得的。通过使用基金会的智力优势和更广泛的影响审查标准进行评估来获得支持。

项目成果

Decay of a Quantum Knot

量子结的衰变

• DOI: 10.1103/physrevlett.123.163003
• 发表时间: 2019-10
• 期刊: Physical Review Letters
• 影响因子: 8.6
• 作者: Ollikainen, T.;Blinova, A.;Möttönen, M.;Hall, D. S.
• 通讯作者: Hall, D. S.

Controlled creation of a singular spinor vortex by circumventing the Dirac belt trick

通过绕过狄拉克带技巧来控制奇异旋量涡旋的产生

• DOI: 10.1038/s41467-019-12787-1
• 发表时间: 2019-12
• 期刊: Nature Communications
• 影响因子: 16.6
• 作者: Weiss, L. S.;Borgh, M. O.;Blinova, A.;Ollikainen, T.;Möttönen, M.;Ruostekoski, J.;Hall, D. S.
• 通讯作者: Hall, D. S.

Existence, stability, and dynamics of monopole and Alice ring solutions in antiferromagnetic spinor condensates

反铁磁旋量凝聚中单极子和爱丽丝环解的存在性、稳定性和动力学

• DOI: 10.1103/physreva.105.053303
• 发表时间: 2021-12-23
• 期刊: Physical Review A
• 影响因子: 2.9
• 作者: T. Mithun;R. Carretero;E. Charalampidis;D. Hall;P. Kevrekidis
• 通讯作者: P. Kevrekidis

Controlled creation and decay of singly-quantized vortices in a polar magnetic phase

极地磁相中单量子化涡旋的受控产生和衰减

• DOI: 10.1038/s42005-021-00554-y
• 发表时间: 2021-12
• 期刊: Communications Physics
• 影响因子: 5.5
• 作者: Xiao, Y.;Borgh, M. O.;Weiss, L. S.;Blinova, A. A.;Ruostekoski, J.;Hall, D. S.
• 通讯作者: Hall, D. S.

Topological superfluid defects with discrete point group symmetries

具有离散点群对称性的拓扑超流体缺陷

• DOI: 10.1038/s41467-022-32362-5
• 发表时间: 2022-08-08
• 期刊: Nature Communications
• 影响因子: 16.6
• 作者: Xiao, Y.;Borgh, M. O.;Blinova, A.;Ollikainen, T.;Ruostekoski, J.;Hall, D. S.
• 通讯作者: Hall, D. S.