Transitions and Complex Order at Ultralow Temperatures

9409590 Osheroff技术摘要：氦3将被用作模型系统，以研究重要物理系统中的相变和复序性质的各个方面。对超流氦三A-B相成核的研究将探索表面粗糙度如何提高成核速率，这可能为该系统在量子隧道研究中的使用铺平道路。将继续研究吸附在石墨上的三层氦的第二层磁序。这项工作的重点是寻找这个二维海森堡系统在低磁场下可能发生的有限温度相变。第三，将开展声学研究，寻找吸附在超流氦四上的亚单分子层氦三膜的第二超导态。最后，将对自旋玻璃中噪声关联的空间相关性进行新的研究。非技术摘要：氦3将被用作一个模型系统，用于研究重要物理系统类中的相变和复杂秩序的性质的各个方面。研究两个液氦三相之间的相变，可能有助于制造出高效的粒子探测器，也有助于从总体上提供关于广泛相变的知识。具有原子核之间有效磁相互作用的薄液氦三层膜将允许测试理论预测，在适当的衬底上薄液氦三层膜可能表现出更新的有序形式，可能与氧化物超导体中看到的那些有序形式有关。***

9409590 Osheroff Technical abstract: Helium three will be used as a model system to study various aspects of the nature of phase transitions and complex order in important classes of physical systems. Work on superfluid helium three A-B phase nucleation will probe how surface roughness increases the nucleation rate, possibly paving the way for the use of this system in quantum tunneling studies. Study of the magnetic order in thr second layer helium three films adsorbed on graphite will be continued. The emphasis of this work is to search for a possible finite temperature phase transition in low magnetic fields for this two dimensional Heisenberg system. Third sound studies will be carried out to search for a second superconducting state of sub-monolayer helium three films adsorbed on superfluid helium four. Finally, new studies of the spatial dependence of noise correlations in spin glasses will be carried out. Non-technical abstract: Helium three will be used as a model system for studying various aspects of the nature of phase transitions and complex order in important classes of physical systems. Studies of the phase transitions between two liquid helium three phases which are neutral analogs to electrical superconductors may help produce a highly effective particle detector, as well shed knowledge on a broad class of phase transitions in general. Thin helium three films which exhibit effective magnetic interactions between the atomic nuclei will allow test theoretical predictions that thin liquid helium three films on appropriate substrates may exhibit still more novel forms of order, possibly related to those seen in the oxide superconductors. ***