Investigation of Superfluid Helium 3

超流氦 3 的研究

• 批准号: 9418665
• 负责人: Richard Packard
• 金额: $ 53.15万
• 依托单位: University of California-Berkeley
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1995
• 资助国家: 美国
• 起止时间: 1995-01-15 至 1998-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9418665&HistoricalAwards=false
• 关键词: Investigation; Superfluid; Helium

9418665 Packard The Principal Investigators will study two questions related to superfluid helium 3, a phase which exists below 2 x 10-3 K. The first area of research involves understanding the nature of helium 3 when it is in the form of films whose thickness is less than the superfluid coherence length. The Principals Investigators will determine if these films will exhibit superfluidity when deposited on helium 4 covered substrates. The initial thrust of the program is to develop tools to study surface waves on the film, so called third sound. These waves will be used as a probe of the films properties. The second area of activity will develop helium 3 dc Josephson junctions. These weak link structures should exhibit a nonlinear current pressure characteristic. These devices may permit the detection of macroscopic quantum interference analogous to the effects seen in dc superconducting quantum interference devices. % % % The rare isotope helium 3 forms a superfluid state at temperatures below 0.002 K. The Principal Investigators will determine if very thin films of this materials will continue to exhibit superfluid properties as the thickness of the sample is made progressively smaller. To answer this question we will develop techniques capable of detecting surface thickness waves. These acoustical techniques will provide insight into the properties of thin films. The properties of the superfluid when it flows through very small apertures will also be studied. It is believed that the fluid passing through submicron apertures will exhibit peculiar behavior which may lead to the development of very sensitive superfluid gyroscopes. ***

小行星9418665 主要研究人员将研究与超流氦3有关的两个问题，超流氦3是一种存在于2 × 10-3 K以下的相。研究的第一个领域涉及理解氦3的性质时，它是在薄膜的形式，其厚度小于超流体相干长度。 主要研究人员将确定这些薄膜沉积在氦4覆盖的基底上时是否会表现出超流性。 该计划的最初目标是开发工具来研究电影中的表面波，即所谓的第三声。 这些波将被用作薄膜性质的探针。 第二个领域的活动将开发氦3直流约瑟夫森结。 这些薄弱环节的结构应表现出非线性的电流压力特性。 这些设备可以允许检测宏观量子干涉类似于直流超导量子干涉设备中看到的效果。 % % % 稀有同位素氦3在低于0.002K的温度下形成超流体状态。 主要研究人员将确定这种材料的非常薄的薄膜是否会随着样品厚度的逐渐变小而继续表现出超流体特性。 为了回答这个问题，我们将开发能够检测表面厚度波的技术。 这些声学技术将提供深入了解薄膜的性质。 还将研究超流体流过非常小的孔隙时的特性。 人们相信，通过亚微米孔的流体将表现出特殊的行为，这可能导致非常敏感的超流体陀螺仪的发展。 ***