Studies of Transport and Many Body Effects in Strongly Correlated Frustrated Lattices

该奖项支持理论研究和教育，旨在阐明相关性对电子受挫系统的异常有序阶段中热和电荷传输的作用。这项工作的动机是最近发现的磁性，不寻常的超导性，和异常的输运行为的钠钴氧化物系统NaxCoO 2和新的有机化合物，显示出量子自旋液体状态的承诺。超导性发生在水合NaxCoO 2，是极端的II型，具有令人费解的对称性。钠电荷有序化以令人惊讶的线性模式发生。在相图中出现了不寻常的磁长程有序。这些实验发现挑战了金属基本理论的原则，表明在这些系统中强的多体相关性的作用。计算传输响应函数的新想法为计算提供了方向，并产生了初步结果，有助于解释大的热电势，其对磁场的极端敏感性，和霍尔常数的线性T依赖性。PI将研究传输特性和发生以及性质的磁性和超导状态，在模型中，是适当的描述这些系统，使用分析和数值技术相结合。主要的重点是开发其他技术，以进一步了解这些系统的多体重整化。非技术性总结：该奖项支持一类材料的理论研究和教育，这些材料显示出不寻常的性质，不遵循标准教科书范式。人们认为，这些材料特有的电子之间的相互作用增强，在理解它们的性质和它们的电子的不寻常的量子力学状态方面发挥着重要作用。PI将进行理论研究，重点是了解这些材料中的电子如何携带电荷和热量。研究这些性质可以提供重要的线索，有助于更广泛地了解这些不寻常的材料及其电子状态。特别感兴趣的材料涉及最近发现的有机化合物和钴轴承材料，该材料表现出不寻常的超导状态，电流可以在没有耗散的情况下流动。这些材料中物质的电子态及其性质是凝聚态物理学领域中具有挑战性的问题。从技术的角度来看，它们也可能令人感兴趣;发电和冷却设备是可能的应用之一。

This award supports theoretical research and education that aims to elucidate the role of correlations on thermal and charge transport in unusual ordered phases of electronically frustrated systems. This work is motivated by recent discoveries of magnetism, unusual superconductivity, and anomalous transport behavior in the sodium cobalt oxide system NaxCoO2 and new organic compounds which show promise of exhibiting quantum spin liquid states.Superconductivity occurs on hydrating NaxCoO2, and is of extreme type II kind, with a puzzling symmetry. Sodium charge ordering occurs in surprising linear patterns. Unusual magnetic long-ranged order occurs in the phase diagram. Such experimental findings challenge the tenets of the basic theory of metals, suggesting the role of strong many body correlations in these systems.New ideas for computing the transport response functions have provided a direction for calculations, and yielded preliminary results that go some distance towards explaining the large thermopower, its extreme sensitivity to magnetic fields, and a linear T dependence of the Hall constant.The PI will study the transport properties and the occurrence as well as nature of the magnetic and superconducting states, in models that are appropriate to describe these systems, using a combination of analytical and numerical techniques. The main focus is to develop other techniques to further understand the many-body renormalizations underlying these systems.NON-TECHNICAL SUMMARY:This award supports theoretical research and education on a class of materials that display unusual properties that do not follow the standard textbook paradigms. It is believed that heightened interactions among electrons peculiar to these materials play an important role in understanding their properties and the unusual quantum mechanical states of their electrons. The PI will carry out theoretical research focused on understanding how charge and heat are carried by the electrons in these materials. Studying these properties can provide important clues that can contribute to a broader understanding of these unusual materials and their electronic states. The materials of particular interest involve recently discovered organic compounds and a cobalt bearing material that exhibits an unusual superconducting state where electric current can flow without dissipation. The electronic states of matter in these materials and their properties are of great fundamental interest and bear on challenging problems in the field of condensed matter physics. They are also potentially interesting from a technological point of view; devices for electric power generation and cooling are among the possible applications.