Violent Events in Superfluid 3Helium and a Collective Model of Glasses

超流体 3 氦中的暴力事件和眼镜的集体模型

• 批准号: 8822688
• 负责人: Anthony Leggett
• 金额: $ 20.86万
• 依托单位: University of Illinois at Urbana-Champaign
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1989
• 资助国家: 美国
• 起止时间: 1989-05-15 至 1993-01-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=8822688&HistoricalAwards=false
• 关键词: Violent; Events; Superfluid; 3Helium; Collective

A study will be made of various types of phenomenon in superfluid 3helium which involve violent departures from equilibrium and/or strongly nonlinear dissipation. Examples of such problems are the way in which textures and bulk magnetization follow the moving A-B interface, dissipation by moving singular vortices, the Josephson effect in both mass and spin supercurrent flow, and the dynamics of a wire vibrating in superfluid 3helium-B at very low tempertures. A conscious attempt will be made to develop intermediate-level, phenomenological concepts for this type of problem, rather than relying on existing microscopic technology. Also an attempt will be made to develop into a quantitative theory a collective scenario for the thermal and acoustic properties of glasses. The scenario is based on the idea that the underlying principle of the striking universality in glassy properties is to be sought in the phonon-mediated interactions of the stress variables of large subvolumes. It is hoped that such a model will replace the currently established "tunnelling two- level system" model at low tempertures, and in addition explain much of the intermediate- and high-temperature behavior, such as the plateau in the thermal conductivity, which is believed to correspond to the point at which the retarded nature of the phonon-induced interaction begins to play a substantial role.

将对超流3He中的各种现象进行研究，这些现象涉及剧烈偏离平衡和/或强烈的非线性耗散。这些问题的例子有织构和块体磁化遵循移动的A-B界面的方式，通过移动奇异涡旋的耗散，质量和自旋超流中的约瑟夫森效应，以及在超流3He-B中极低温度下振动的导线的动力学。将有意识地尝试为这类问题开发中级的现象学概念，而不是依赖现有的微观技术。此外，还将尝试将玻璃的热学和声学性质的集体情景发展成一种量化理论。这一设想是基于这样一种想法，即玻璃性质中惊人的普遍性的基本原理是在大子体积的应力变量的声子介导的相互作用中寻找的。人们希望这样的模型将取代目前建立的低温下的隧道二能级系统模型，并解释许多中高温行为，如热导率中的平台，这被认为对应于声子诱导的相互作用的延迟性质开始发挥实质性作用的点。