New Phases of Superfluid 3He

超流体 3He 的新相

• 批准号: 0703656
• 负责人: William Halperin
• 金额: $ 62万
• 依托单位: Northwestern University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-08-01 至 2011-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0703656&HistoricalAwards=false
• 关键词: New; Phases; Superfluid; 3He

****NON-TECHNICAL ABSTRACT****In this individual investigator project new high frequency acoustic techniques will be employed to explore the structure of 3He superfluids. The goal is to determine the role of impurities and surface conditions on superfluid 3He and to search for new phases that have been predicted to exist. Such effects are particularly easily controlled in 3He but their existence may be general to other related condensed phases such as the high temperature superconductors. Thus the research may have a significant impact on our society. The stabilization of new superfluid states requires synthesis of aerogels, extremely porous but fairly robust glass solids. Local high school and undergraduate students will be involved in this synthesis. Materials will also be provided collaboratively to laboratories in USA, France, and the United Kingdom for a range of applications. Graduate and undergraduate students will obtain training in technically sophisticated techniques including of small angle x-ray scattering, low-temperature methods, and high frequency acoustics. This will prepare them for a range of professional career opportunities with a significant potential impact to our society.****TECHNICAL ABSTRACT****This individual investigator award supports a project aimed at understanding the new phases and unusual properties of superfluid 3He that have recently been discovered as a consequence of introducing impurities into the superfluid using high porosity silica aerogels. This project aims to address; "What are the stable phases and what determines the transition from one to another?" The effect of correlations between impurities and the possible stabilization of interesting new states of matter by organizing these impurities with externally imposed global anisotropy will also be explored. Heat capacity and high frequency acoustic measurements will be performed at low-temperatures to investigate the superfluid order parameter and phase stability. Additionally, the basic interactions responsible for, and competing with, superfluidity will be measured. New acoustic cavity methods will be developed and applied to explore newly discovered magneto-acoustic effects and to look for stripe phases that have been predicted to form in thin slabs. This research may impact on our understanding of high temperature superconductivity, and thus future technologies. The silica aerogels will be grown and characterized with the involvement of undergraduate and high school students. Characterization will be performed using the small angle X-ray scattering facilities at the Advanced Photon Source, Argonne National Laboratory. Undergraduate and graduate students will obtain training in technically sophisticated techniques, which will prepare them for a range of professional career opportunities with a significant potential impact on our society.

* 非技术摘要 * 在这个个人研究项目中，将采用新的高频声学技术来探索3 He超流体的结构。 目标是确定杂质和表面条件对超流3 He的作用，并寻找预测存在的新相。 这种效应在3 He中特别容易控制，但它们的存在可能普遍存在于其他相关的凝聚相，如高温超导体。因此，这项研究可能会对我们的社会产生重大影响。 新的超流体状态的稳定需要合成气凝胶，非常多孔但相当坚固的玻璃固体。 当地高中和本科生将参与这一综合。材料还将合作提供给美国，法国和英国的实验室，用于一系列应用。 研究生和本科生将获得技术复杂的技术培训，包括小角度X射线散射，低温方法和高频声学。 这将使他们为一系列对我们社会有重大潜在影响的职业机会做好准备。技术摘要 * 该个人研究者奖支持一个项目，旨在了解超流3 He的新相和不寻常的性质，这些性质最近被发现是使用高孔隙率二氧化硅气凝胶将杂质引入超流的结果。 该项目旨在解决;“什么是稳定阶段，是什么决定了从一个过渡到另一个？“还将探讨杂质之间的相关性的影响，以及通过将这些杂质与外部强加的全局各向异性相结合，可能稳定有趣的新物质状态。 热容和高频声学测量将在低温下进行，以研究超流序参量和相稳定性。此外，负责的基本相互作用，并与超流性的竞争将被测量。 新的声腔方法将被开发和应用，以探索新发现的磁声效应，并寻找已预测在薄板中形成的条纹相。 这项研究可能会影响我们对高温超导性的理解，从而影响未来的技术。 二氧化硅气凝胶将在本科生和高中生的参与下生长和表征。 将使用阿贡国家实验室高级光子源的小角度X射线散射设施进行表征。 本科生和研究生将获得技术先进的技术培训，这将为他们提供一系列对我们社会有重大潜在影响的职业机会。