Topological Surface States and New Phases in Superfluid 3He

超流体 3He 的拓扑表面态和新相

• 批准号: 1103625
• 负责人: William Halperin
• 金额: $ 82.5万
• 依托单位: Northwestern University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-08-01 至 2017-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1103625&HistoricalAwards=false
• 关键词: Topological; Surface; States; New; Phases

Technical AbstractThis individual investigator project trains graduate and undergraduate students who conduct research on the structure of various quantum condensed phases with a focus on 3He superfluids at low temperatures. The central part of this proposal is to characterize certain types of quantum states which have topological significance and can be found at the surface of these superfluids. The impact of the research will be felt over a broad range of condensed matter physics, on field theories basic to the understanding of neutrinos, and may have relevance to the understanding of dark matter. New superfluid phases of helium have been predicted to exist within globally-anisotropic, highly-porous, silica aerogels. These materials will be grown with assistance from undergraduate students who characterize them using optical birefringence, and small angle Xray techniques. Additionally, our aerogels will be provided to a half-dozen laboratories around the world where there have been specific requests. High-resolution acoustics in resonant cavities will be used used to investigate surface quantum states in thin samples of superfluid 3He and a search for direct evidence of broken, time-reversal symmetry will be conducted. This fundamental broken symmetry is of importance to studies on various unconventional superconducting materials conducted in other laboratories.Non-Technical AbstractThis individual investigator project supports graduate and undergraduate education through their research in experimental physics. The project develops, creates, and characterizes new quantum states of matter which exhibit symmetry properties that have the potential for impact on our society, including high speed computation, transfer of mass in the form of frictionless superfluids, as well as applications of superconductivity. Highly porous, gel structures, so-called aerogels, will be grown and characterized in order to control the quantum states of helium superfluids imbibed within. These highly homogeneous samples will also be provided to a half dozen other laboratories that have requested them. The basic scientific research conducted in this project provides student training in high-resolution acoustics, nuclear magnetic resonance, and low temperature techniques and promotes awareness in both public and scientific communities to conserve helium as a valuable natural resource.

技术摘要：本项目培养研究生和本科生对低温下3He超流体的各种量子凝聚态结构进行研究。这个建议的核心部分是表征某些类型的量子态，这些量子态具有拓扑意义，可以在这些超流体的表面找到。这项研究的影响将在凝聚态物理的广泛范围内感受到，在理解中微子的基础场论上，并且可能与理解暗物质有关。新的超流相氦已经被预测存在于全局各向异性，高多孔，二氧化硅气凝胶中。这些材料将在本科生的帮助下生长，他们将使用光学双折射和小角度x射线技术对其进行表征。此外，我们的气凝胶将提供给世界各地有特定需求的六个实验室。共振腔中的高分辨率声学将用于研究超流体3He薄样品中的表面量子态，并将寻找破缺的直接证据，时间反转对称性将被进行。这种基本的对称性破缺对其他实验室进行的各种非常规超导材料的研究具有重要意义。这个个人研究者项目通过他们在实验物理方面的研究来支持研究生和本科生的教育。该项目开发、创造并描述了新的物质量子态，这些物质表现出对称特性，对我们的社会有潜在的影响，包括高速计算、无摩擦超流体形式的质量传递，以及超导的应用。高度多孔的凝胶结构，即所谓的气凝胶，将被培养和表征，以控制氦超流体的量子态。这些高度均匀的样品也将提供给其他六个有要求的实验室。该项目开展的基础科学研究为学生提供了高分辨率声学、核磁共振和低温技术方面的培训，并提高了公众和科学界保护氦这一宝贵自然资源的意识。