U.S.-France Cooperative Research: Nuclear Magnetic Properties of Superfluid 3He in Bulk and Confined Geometries

[128811]这项为期三年的美法凝聚态物理合作奖涉及康奈尔大学和法国格勒诺布尔低温物理研究中心的研究小组。David M. Lee, Jeevak M. Parpia和John Reppy领导美国的工作；尤里·邦科夫（Yuriy Bunkov）和亨利·戈德林（Henri Godrin）领导了法国团队。研究的重点是超流体3He（氦）——一种独特的相干量子系统，其序参量显示了规范对称性和旋转对称性的复杂破缺。研究的主要领域是体超流体3HeB的弛豫域和气凝胶中液体3He的超流动性性质。该项目涉及在高磁场和超低温下对3He进行核磁共振（NMR）研究。康奈尔小组的实验包括探索磁场对温度突变关系的依赖以及气凝胶中声音传播和热传递作为磁场的函数。这是由法国在超低温极限下对气凝胶中超流体3He的核磁共振研究以及理论研究和灾难性弛豫的数值模拟所补充的。该奖项代表了美国方面向美国国家科学基金会和法国国家科学研究中心（CNRS）联合提出的建议。美国国家科学基金会将承担美国研究人员和博士后研究人员的旅费和生活费。CNRS将支持法国参与者访问美国。该合作将促进对3He系统及其在宇宙学和高能物理中的应用的理解。

0128811LeeThis three-year award for U.S.-France collaboration in condensed matter physics involves research groups at Cornell University and the Center for Low Temperature Physics Research in Grenoble, France. David M. Lee, Jeevak M. Parpia and John Reppy lead the US effort; Yuriy Bunkov and Henri Godrin lead the French group. The focus of the research is superfluid 3He (helium) - a unique coherent quantum system whose order parameter shows the complex breaking of gauge and rotation symmetries. The main areas to be studied are the relaxation domains in bulk superfluid 3HeB and the nature of the superfluidity of liquid 3He in aerogel. The project involves nuclear magnetic resonance (NMR) studies of 3He at high magnetic fields and at ultra low temperatures. The Cornell group's experiments include exploration of magnetic field dependence of the temperature of catastrophic relation and sound propagation and heat transport in aerogel as a function of magnetic field. This is complemented by French NMR studies of superfluid 3He in aerogel at the limit of ultra low temperatures and theoretical investigations and numerical simulations of catastrophic relaxation. This award represents the US side of joint proposals to the NSF and the French National Center for Scientific Research (CNRS). NSF will cover travel funds and living expenses of the US investigators and postdoctoral researchers. The CNRS will support visits to US of the French participants. The collaboration will advance understanding of 3He systems and applications in cosmology and high-energy physics.