Effects of Confinement on Quantum Fluids

限制对量子流体的影响

• 批准号: 9971471
• 负责人: Moses Chan
• 金额: $ 42万
• 依托单位: Pennsylvania State Univ University Park
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1999
• 资助国家: 美国
• 起止时间: 1999-06-15 至 2002-10-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9971471&HistoricalAwards=false
• 关键词: Effects; Confinement; Quantum; Fluids

This is an experimental condensed matter physics project that seeks to understand the effect of confining liquid helium into one and two dimensions. It has been shown that on a hydrogen surface, the inert layer, or the minimum helium coverage for the appearance of superfluidity in the T=0 limit, is half a liquid monolayer. This raises the question of whether the inert layer can be reduced further on an even weaker substrate, such as an alkali metal surface. A recent calculation predicted that on a cesium-silver compound surface, a dilute hydrogen layer will not solidify and will exhibit superfluid behavior. It has been found recently that helium-3 and other gases are easily adsorbed into the interior of single-wall-carbon-nanotubes. If helium remains liquids at low temperatures, as is predicted, this will be an experimental realization of one dimensional Luttinger liquid. Torsional oscillator, heat capacity and pulsed NMR techniques will be employed to study these confined quantum systems.%%%This is an experimental condensed matter physics project that seeks to understand the consequences of confining liquid helium in one and two dimensions. Liquid helium is an unique liquid in that its properties are dominated by quantum mechanics at low temperatures and transforms into a superfluid. The physics of the superfluid state is analogous to the superconducting state of certain metals and alloys. By adsorbing atomically thin helium films onto solid surfaces an into the interior channels of recently discovered single-all-carbon nanotubes, the properties of superfluidity in two and one dimensions can be explored with highly sensitive mass decoupling and other techniques. In addition to addressing a number of fundamental questions of quantum systems in reduced dimensions, these experiments will also shed insights on the physics of high temperature superconductors and on artificially engineered nanoscale structures. Students associated with this project will receive excellent training, with state-of-the-art instrumentation, that will prepare them for careers in academia or industry.

这是一个实验性凝聚态物理项目，旨在了解将液氦限制在一维和二维的效果。研究表明，在氢表面上，惰性层或在 T=0 极限下出现超流性的最小氦覆盖范围是半个液体单层。这就提出了一个问题：是否可以在更弱的基材（例如碱金属表面）上进一步还原惰性层。最近的一项计算预测，在铯银化合物表面，稀氢层不会凝固，而是会表现出超流体行为。最近发现，氦3等气体很容易被吸附到单壁碳纳米管的内部。如果氦在低温下保持液态，正如预测的那样，这将是一维卢廷格液体的实验实现。扭转振荡器、热容和脉冲核磁共振技术将用于研究这些受限量子系统。%%%这是一个实验性凝聚态物理项目，旨在了解在一维和二维中限制液氦的后果。液氦是一种独特的液体，其性质在低温下受量子力学支配，并转变为超流体。超流体状态的物理学类似于某些金属和合金的超导状态。通过将原子级薄氦膜吸附到固体表面和最近发现的单个全碳纳米管的内部通道中，可以利用高度灵敏的质量解耦和其他技术来探索二维和一维的超流特性。除了解决降维量子系统的许多基本问题外，这些实验还将深入了解高温超导体的物理原理和人工设计的纳米级结构。与该项目相关的学生将接受一流的培训，并配备最先进的仪器，这将为他们在学术界或工业界的职业生涯做好准备。