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

强相关受阻晶格中的传输和许多身体效应的研究

• 批准号: 0706128
• 负责人: Sriram Shastry
• 金额: $ 30万
• 依托单位: University of California-Santa Cruz
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-09-01 至 2011-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0706128&HistoricalAwards=false
• 关键词: Studies; Transport; Many; Body; Effects

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.

该奖项支持理论研究和教育，旨在阐明相关性在电子挫败系统的异常有序阶段中相关性在热和电荷传输中的作用。这项工作是由磁性，异常超导性和氧化钠系统NAXCOO2和新的有机化合物中的磁性，异常的超导性和异常运输行为的动机所激发的，这些有望表现出量子旋转液态状态的希望。在水分naxcoo2上表现出量子旋转液态。钠电荷排序以惊人的线性模式发生。异常的磁长阶在相图中发生。这种实验发现挑战了金属基本理论的原则，这表明了强大的许多身体相关性在这些系统中的作用。新计算运输响应函数的想法为计算提供了方向，并产生了初步结果，这些结果距离磁场和磁场的极端敏感性以及在霍尔的范围内的极端敏感。超导状态，在适合描述这些系统的模型中，结合了分析和数值技术。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新构化。没有技术摘要：该奖项支持一系列材料的理论研究和教育，这些材料显示出异常属性，这些属性不遵循标准教科书范式。据信，这些材料特有的电子之间的相互作用加剧在理解其特性和电子的异常量子机械状态方面起着重要作用。 PI将进行理论研究，重点是了解这些材料中电子如何携带电荷和热量。研究这些特性可以提供重要的线索，从而有助于对这些异常材料及其电子状态有更广泛的了解。特别感兴趣的材料涉及最近发现的有机化合物和一种钴轴承材料，表现出异常的超导状态，在这种状态下，电流可以流动而不会消散。这些材料及其特性中物质的电子状态具有极大的基本兴趣，并且对凝聚态物理学领域的具有挑战性的问题承受着。从技术的角度来看，它们也可能很有趣。发电和冷却的设备是可能的应用。