Disorder Induced Novel Quantum Phases in Superfluid 3He

超流体 3He 中无序诱导的新型量子相

• 批准号: 0803516
• 负责人: Yoonseok Lee
• 金额: $ 34.5万
• 依托单位: University of Florida
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-05-01 至 2012-04-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0803516&HistoricalAwards=false
• 关键词: Disorder; Induced; Novel; Quantum; Phases

****NON-TECHNICAL ABSTRACT****The physics of disorder is integrated in an extremely large area of science as a common thread, and the impact of research on this subject permeates from the highly practical to the purely academic. This project addresses a fundamental question: ?How does the nature of a quantum matter evolve in response to disorder?? Unlike other physical systems, the liquid state of 3He at low temperatures is a unique, practically disorder free system for which we have a quantitative understanding. Furthermore, the superfluid phases of 3He, which can be characterized more generally as unconventional superconductivity, are known to exhibit extreme sensitivity to external disorder. This project will investigate the effect of controlled disorder on this unique quantum state of matter. The effect of two distinct forms of disorder: anisotropic disorder in high porosity aerogel and surface disorder in thin films of liquid will be studied. The ultimate goal of the project is to identify novel, disorder-induced quantum phases which have been predicted to emerge in these systems. The research will be conducted by two teams of graduate and undergraduate students. Undergraduate research is an important element of education and also an effective way of retaining Physics undergraduate students in this field. The PI of the project will continue to interact with local science teachers and students through lectures/demonstrations and participation in science fairs. ****TECHNICAL ABSTRACT****This project will investigate the superfluid phases of 3He in the presence of controlled disorder presented by high porosity aerogel and by confinement in the form of films. The ultimate goal of the proposed project is to identify disorder-induced novel quantum phases which have been predicted to emerge in these systems. The effect of anisotropic disorder on anisotropic superfluid can be studied in a systematic way in uniaxially deformed aerogel. The 1D-like polar phase is predicted to be stabilized due to anisotropic disorder induced in stretched aerogel. Experiments will be performed to elucidate the effect of surface disorder on superfluid 3He employing state-of-the-art microelectro-mechanical systems (MEMS) to form controlled films and to detect various phase transition features. This project will focus on quasi-two dimensional films where the re-entrant behavior of the A-B transition and the emergence of an inhomogeneous superfluid phase have been theoretically predicted. The proposed research will be conducted by two teams of graduate and undergraduate students. Retaining Physics undergraduate students is as important as increasing their number. One effective way is undoubtedly through undergraduate research.

****非技术摘要****无序物理学作为一条主线整合在一个极其广阔的科学领域中，对该主题的研究影响从高度实用到纯粹的学术。该项目解决了一个基本问题：“量子物质的性质如何响应无序而演化？” 与其他物理系统不同，3He在低温下的液态是一种独特的、几乎无序的系统，我们对此有定量的了解。 此外，3He 的超流相可以更普遍地表征为非常规超导性，已知对外部紊乱表现出极端的敏感性。 该项目将研究受控无序对这种独特的物质量子态的影响。 将研究两种不同形式的无序的影响：高孔隙率气凝胶中的各向异性无序和液体薄膜中的表面无序。 该项目的最终目标是识别预计会在这些系统中出现的新型无序诱导量子相。 该研究将由研究生和本科生两个团队进行。 本科生科研是教育的重要组成部分，也是留住物理学本科生的有效途径。 该项目的PI将继续通过讲座/演示和参加科学博览会的方式与当地科学教师和学生进行互动。 ****技术摘要****该项目将研究 3He 在高孔隙率气凝胶和薄膜形式约束所呈现的受控无序情况下的超流体相。 该项目的最终目标是识别无序引发的新型量子相，这些相预计会出现在这些系统中。可以在单轴变形气凝胶中系统地研究各向异性无序对各向异性超流体的影响。由于拉伸气凝胶中诱导的各向异性紊乱，预计类一维极性相会稳定。 将进行实验来阐明表面紊乱对超流体 3He 的影响，采用最先进的微机电系统 (MEMS) 形成受控薄膜并检测各种相变特征。该项目将重点关注准二维薄膜，其中 A-B 转变的重入行为和不均匀超流体相的出现已在理论上得到预测。拟议的研究将由研究生和本科生两个团队进行。 留住物理学本科生与增加其数量同样重要。 一种有效的方法无疑是通过本科生研究。