Collective Phenomena in Quantum Fluids

该项目解决了超流He-3和自旋的性质， 极化He-3/He-4混合物。 He-3作为模型复合体 超流体 该系统的实验结果与其他高性能的 相关系统，包括高温超导体。 的 超流体中的集体模式将由 声学方法，包括第二声。 另外的实验 将使用核磁共振作为表征探针。 稀释自旋极化He-3/He-4混合物的实验将 重点放在弛豫过程中的流体，产生通过域 流体中的壁或孤子运动。 研究的一个目标是 确定直接辐射的相对重要性 与自旋波的辐射相比， 磁畴壁在磁场中移动。 %%% 该项目研究流体的基本性质， 非常低的温度。 这些“超流体”表现出 与高温超导体有关， 仍然无法解释 超流体还提供了模型系统， 研究流体混合物的基本热力学。 再次 结果与较高温度下的系统相关， 实际条件。 最后，作者有一个设施， 提供了一种将非常大的磁场施加到样品上的方法 因此进行了独特的实验来研究磁畴 壁运动，以及磁流体所表现出的其他动力学行为。 材料.

This project addresses the properties of superfluid He-3 and spin- polarized He-3/He-4 mixtures. He-3 serves as model complex superfluid. Experiments on this system relate to other highly correlated systems, including high-Tc superconductors. The collective modes in the superfluids will be investigated by acoustical methods, including second-sound. Additional experiments will use nuclear magnetic resonance as a characterization probe. The experiments on dilute spin polarized He-3/He-4 mixtures will focus on relaxation process in the fluids which arise via domain wall or soliton motion in the fluids. A goal of the research is to determine the relative importance of direct radiation of radiofrequency, as compared with radiation of spin waves, as a domain wall moves in a magnetic field. %%% This project investigates the fundamental properties of fluids at very low temperatures. These "superfluids" exhibit behavior related to high-temperature superconductors, whose properties remain unexplained. The superfluids also provide model system for studying fundamental thermodynamics of fluid mixtures. Again, the results are relevant to systems at higher temperatures and in practical conditions. Finally, the author has a facility that provides a way to apply a very large magnetic field to the samples and hence carry out unique experiments to study magnetic domain wall motion, and other dynamical behavior exhibited by magnetic materials.