Studies of Quantum Fluids and Solids

量子流体和固体的研究

• 批准号: 9623777
• 负责人: Robert Richardson
• 金额: --
• 依托单位: Cornell University
• 依托单位国家: 美国
• 项目类别: Continuing grant
• 财政年份: 1996
• 资助国家: 美国
• 起止时间: 1996-05-01 至 2000-04-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9623777&HistoricalAwards=false
• 关键词: Studies; Quantum; Fluids; Solids

9623777 Richardson The theme of the proposed work is to examine the consequences of the very large amplitude quantum motion in solid helium. The first objective is to observe and measure the rates of exchange of 3He atoms in three, four, and six particle rings. According to theory, the ring-like exchange motion is responsible for the unique nuclear magnetic ordering in solid 3He. The ring exchange motion has never been directly observed. Special nmr techniques will have to be developed for the observation. A further objective of the work is an attempt to see new modes of atomic motion by using Magnetic Resonance Imaging. Several unusual and important phenomena have been predicted but have never been observed. %%% The researchers will use nuclear magnetic resonance techniques to study a remarkably interesting material, solid helium. Because helium has such a very light mass, its atomic motion is quite large even near absolute zero temperature. Modern magnetic resonance techniques will be used to study the nature and consequences of that motion. For example, the zero temperature state of solid helium has been predicted to have the atoms moving rapidly in ring like rotations, rather than sitting quietly at fixed crystalline lattice points. ***

所提出的工作的主题是检查固体氦中非常大振幅量子运动的结果。第一个目标是观察和测量3、4和6个粒子环中3He原子的交换速率。根据理论，环形交换运动是固体3He中独特的核磁有序的原因。环交换运动从未被直接观察到。必须开发特殊的核磁共振技术来进行观测。这项工作的进一步目标是试图通过使用磁共振成像来观察原子运动的新模式。一些不寻常和重要的现象已经被预测到，但从未被观察到。研究人员将使用核磁共振技术来研究一种非常有趣的材料——固体氦。因为氦的质量非常轻，即使在绝对零度附近，它的原子运动也非常大。现代磁共振技术将用于研究这种运动的性质和后果。例如，据预测，固态氦的零温度状态会使原子以环状旋转的方式快速移动，而不是安静地坐在固定的晶格点上。＊＊＊