Microscopy of Ultracold Magnetic Quantum Fluids

超冷磁性量子流体的显微镜检查

• 批准号: 2207367
• 负责人: Richard Fletcher
• 金额: $ 45万
• 依托单位: Massachusetts Institute of Technology
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-07-01 至 2025-06-30
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2207367&HistoricalAwards=false
• 关键词: Microscopy; Ultracold; Magnetic; Quantum; Fluids

Long-range interactions mediate many of the most exciting, but poorly understood, phenomena in nature, driving phenomena as diverse as superconductivity, the structures inside neutron stars, and the physics of the early Universe. They determine the arrangement of water molecule networks coating proteins and the physics of magnetic thin films promising new platforms for computer memory and logic. Competition between different forces drives pattern formation in biology, chemical reactions, collider physics, atmospheric, oceanic, and plasma science. In particular, understanding the consequences of long-range forces in systems governed by quantum mechanics is simultaneously theoretically difficult, and essential for designing new materials which exploit quantum behaviors. In this program, the research team will prepare a gas of magnetic atoms, cooled down to billionths of a degree above absolute zero, and confined into a sheet by precisely sculpted laser beams. This forms a flexible experimental arena to explore and understand the role of long-range magnetic forces, ranging from self-organization into intricate structures, the mechanisms underpinning superfluidity, and the dynamics of individual quanta of circulation inside the fluid. The regime of validity for many existing theories of two-dimensional magnetic gases is unclear, motivating the development of precisely controlled experimental platforms. Cutting-edge quantum gas research entails a combination of optics, quantum physics, computer control, electronics and vacuum hardware. The apparatus is entirely built and run by undergraduates, graduate students, and postdocs. This provides an ideal training for the future quantum workforce, equipping group members to be leaders in both academic and industrial quantum research and development.The PI and his undergraduate and graduate students will employ a gas of highly-magnetic erbium atoms, confined to an oblate geometry via an optical lattice and imaged using a high-resolution microscope objective. This will provide a powerful platform for exploring collective physics mediated by a subtle interplay of short-ranged interactions, long-range anisotropic magnetic forces, kinetic energy, trapping potentials, and quantum fluctuations, leading to a plethora of predicted emergent phases. The research team will investigate the core structure and collective dynamics of quantum vortices, spontaneous pattern formation and density ordering, and the influence of long-range interactions on the superfluid Berezinskii–Kosterlitz–Thouless (BKT) transition. On the one hand, these experiments will constitute a striking qualitative demonstration of long-predicted emergent phases in dipolar fluids. On the other, they will provide essential quantitative benchmarks against which to test our current understanding of the interplay between long-range forces, quantum fluctuations, and reduced dimensionality, and the new phases of matter which emerge.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.

长程相互作用介导了自然界中许多最令人兴奋但知之甚少的现象，驱动了超导性、中子星内部结构和早期宇宙物理学等多种现象。它们决定了包裹蛋白质的水分子网络的排列，以及磁性薄膜的物理特性，这些都为计算机存储器和逻辑提供了新的平台。不同力量之间的竞争推动了生物学、化学反应、对撞机物理学、大气、海洋和等离子体科学中的模式形成。特别是，理解由量子力学控制的系统中长程力的后果在理论上是困难的，同时对于设计利用量子行为的新材料至关重要。在这个项目中，研究小组将准备一种磁性原子气体，冷却到绝对零度以上十亿分之一度，并通过精确雕刻的激光束限制在一个薄片中。这形成了一个灵活的实验竞技场，以探索和理解远程磁力的作用，从自组织到复杂的结构，支撑超流的机制，以及流体内部循环的单个量子的动力学。许多现有的二维磁性气体理论的有效性尚不清楚，这促使了精确控制实验平台的发展。尖端的量子气体研究需要光学、量子物理、计算机控制、电子和真空硬件的结合。该仪器完全由本科生、研究生和博士后建造和运行。这为未来的量子工作人员提供了理想的培训，使小组成员成为学术和工业量子研究与开发的领导者。PI和他的本科生和研究生将使用高磁性铒原子气体，通过光学晶格限制在扁球形几何形状中，并使用高分辨率显微镜物镜成像。这将为探索集体物理学提供一个强大的平台，这些物理学由短程相互作用、长程各向异性磁力、动能、捕获势和量子涨落的微妙相互作用介导，从而导致大量预测的涌现阶段。该研究小组将研究量子涡旋的核心结构和集体动力学，自发模式形成和密度有序，以及长程相互作用对超流Berezinskiii-Kosterlitz-BKT转变的影响。 一方面，这些实验将构成偶极流体中长期预测的涌现阶段的惊人的定性演示。另一方面，它们将提供基本的定量基准，以检验我们目前对长程力、量子涨落和降维之间的相互作用的理解，以及出现的物质的新阶段。该奖项反映了NSF的法定使命，并通过使用基金会的智力价值和更广泛的影响审查标准进行评估，被认为值得支持。