RUI: Computational Studies of Spin-Polarized Quantum Fluids and Solids

RUI：自旋极化量子流体和固体的计算研究

• 批准号: 0071706
• 负责人: Robert Ragan
• 金额: $ 5万
• 依托单位: University of Wisconsin-La Crosse
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2000
• 资助国家: 美国
• 起止时间: 2000-05-01 至 2002-04-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0071706&HistoricalAwards=false
• 关键词: RUI; Computational; Studies; Spin; Polarized

0071706RaganThis is an RUI award to support numerical and analytical approaches to study the spin dynamics of paramagnetic quantum fluids and solids. The research consists of two parts: analysis of spin-wave instabilities in spin-echo experiments, and computer simulation of spin diffusion in solid helium-3. The first part involves the detailed computer simulation and analysis of NMR experiments currently being planned at the National High Magnetic Field Laboratory to detect the long predicted, and recently disputed, zero temperature attenuation of transverse spin currents in spin-polarized Fermi liquids. This effort builds on previous progress and the results should be key in assessing the validity of data obtained in future experiments at ultra-low temperatures and high magnetic fields. The second project will lend computational support to recent attempts by Cowan and Mullin to use linear response theory to calculate spin diffusion coefficients in spin-polarized solid helium-3. In the calculation, a method originated by Kubo is used to relate the long-time diffusive behavior of the spin-correlation function to the local interactions at microscopic time scales. The goal of this project is to assess the validity of this method by calculating the spin correlation function using molecular dynamics simulations from initial conditions generated with Monte Carlo techniques. The bulk of the computations will be performed on the IBM SP at the San Diego Supercomputer Center. Undergraduates will participate in these calculations as part of the university commitment to undergraduate research participation and as part of the Computational Physics Emphasis.%%%This is an RUI award to support numerical and analytical approaches to study the spin dynamics of paramagnetic quantum fluids and solids. The research consists of two parts: analysis of spin-wave instabilities in spin-echo experiments, and computer simulation of spin diffusion in solid helium-3. Undergraduates will participate in these calculations as part of the university commitment to undergraduate research participation and as part of the Computational Physics Emphasis.***

0071706 Ragan这是一个RUI奖，以支持数值和分析方法来研究顺磁性量子流体和固体的自旋动力学。 研究工作包括两部分：自旋回波实验中自旋波不稳定性的分析和固体氦-3中自旋扩散的计算机模拟。 第一部分涉及详细的计算机模拟和分析NMR实验目前正在计划在国家高磁场实验室检测长期预测，最近有争议的，零温度衰减的横向自旋极化费米液体的自旋电流。 这项工作建立在以前的进展基础上，其结果应该是评估未来在超低温和高磁场下实验中获得的数据有效性的关键。 第二个项目将为科万和穆林最近尝试使用线性响应理论计算自旋极化固体氦-3中的自旋扩散系数提供计算支持。 在计算中，Kubo提出的方法被用来将自旋相关函数的长时间扩散行为与微观时间尺度上的局域相互作用联系起来。 该项目的目标是评估这种方法的有效性，通过计算自旋相关函数，使用分子动力学模拟从初始条件产生的Monte Carlo技术。 大部分计算将在圣地亚哥超级计算机中心的IBM SP上进行。 本科生将参与这些计算，作为大学对本科生参与研究的承诺的一部分，并作为计算物理重点的一部分。%这是一个RUI奖，以支持数值和分析方法来研究顺磁性量子流体和固体的自旋动力学。 研究工作包括两部分：自旋回波实验中自旋波不稳定性的分析和固体氦-3中自旋扩散的计算机模拟。本科生将参与这些计算作为大学对本科生参与研究的承诺的一部分，并作为计算物理重点的一部分。