U.S.-Finland Cooperative Research on Quantum Liquid Mixtures in 2, 2+1 and 3 Dimensions

该奖项支持得克萨斯大学的埃克哈德·克罗切克教授 大学（TAMU）在理论物理学方面与 理论系的Mikko Saarela教授 芬兰欧卢大学物理系。 他们有两 共同研究的原则。 一个是制作一个 结构和激发的微观描述 量子流体氦-4和氦-3的均匀混合物， 二维和三维。 他们特别感兴趣的是 临界浓度和集体激发， 有效质量和混合物的动态形状因子。 作为 第二条研究路线， 与这些薄膜的非连续断裂几何形状有关， 吸附在基质上的同位素元素。 他们来了 试图产生一个半定量的描述， 氦-4和氦-3液体之间的界面及其 集体兴奋 这项研究严重依赖于 合作科学家的互补专业知识， 是有效分工的基础。 所有 对时间相关函数的数值计算工作将是 在芬兰完成，所有关于非统一系统的工作都在 塔穆 散装混合物的工作将继续进行， 两个地点。 萨雷拉教授推导出了 结果必要的包容性和优化的三个- 身体相关性，Krotscheck教授已经计算出了 环形图的CBF修正 目前正在绘制基本图。 拟议的工作是建立在一个富有成效的合作， 强相互作用多体理论的一般领域 系统. 混合物问题的彻底研究 氦-3和氦-4需要最先进的多体 超越前人水平的理论 在微观上试图理解量子液体混合物。 拟议的研究将有助于加强 量子物理学中的多体理论 它适用于国家的- 艺术的方法，几个有趣的问题， 及时地进行实验研究， 还有一些可以完善这个理论

This award supports Professor Eckhard Krotscheck of Texas A & M University (TAMU) to collaborate in theoretical physics with Professor Mikko Saarela of the Department of Theoretical Physics of the University of Oulu, Finland. They have two principle lines of joint research. One is to produce a microscopic description of the structure and the excitations of uniform mixtures of the quantum fluids Helium-4 and Helium-3 in two and three dimensions. They are particularly interested in critical concentrations and in the collective excitations, the effective mass, and the dynamic form factor of the mixture. As a second line of research, they are working on questions related to the symmetry-broken geometry of films of these isotopic elements adsorbed to a substrate. Here they are seeking to produce a semi-quantitative description of the interface between the Helium-4 and the Helium-3 liquid and its collective excitation. This research relies heavily upon the complementary expertise of the collaborating scientists which is the basis for an effective division of labor. All of the numerical work on time-dependent correlation functions will be done in Finland, and all the work on non-uniform systems at TAMU. The work on bulk mixtures will continue to be done at both locations. Professor Saarela has derived most of the results necessary for the inclusion and optimization of three- body correlations, and Professor Krotscheck has worked out the CBF (correlated basis functions) corrections of ring diagrams and is presently working on the elementary diagrams. The proposed work builds on a productive collaboration in the general area of the theory of strongly interacting many-body systems. A thorough investigation of the problem of mixtures of Helium-3 and Helium-4 requires state-of-the-art many body theory at a level that is beyond what has been done previously in microscopic attempts to understand quantum liquid mixtures. The proposed research will contribute to such strengthening of many-body theory in quantum physics. It applies state-of-the- art approaches to several interesting questions and is linked in a timely fashion to experimental research being done by others which will refine the theory.