Physical Properties of Strongly Correlated Quantum Liquids

强相关量子液体的物理性质

• 批准号: 0706078
• 负责人: Xiao-Gang Wen
• 金额: $ 39万
• 依托单位: Massachusetts Institute of Technology
• 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: 2007-11-01 至 2010-10-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0706078&HistoricalAwards=false
• 关键词: Physical; Properties; Strongly; Correlated; Quantum

TECHNICAL SUMMARY:This award supports theoretical research and education in condensed matter physics with an emphasis on a deeper understanding of the notion of order in states of matter. A comprehensive theory for symmetry breaking order has been developed, based on the concept of an order parameter, Ginzburg-Landau theory, and group theory. Such a theory forms a corner stone in the foundation of condensed matter theory. The PI has proposed the concepts of topological order and quantum order that are outside the standard Landau-Ginzburg theory of phase transitions. In this research project, the PI plans to develop a more complete theory of topological/quantum order. Specifically, the PI plans to apply the string-net mean-field theory to realistic quantum spin systems to identify materials that may contain non-trivial topological/quantum order. Strong fluctuations of ends of string and their close tie to the continuous transition between topological states will be studied. This may lead to a general theory for topological phase transitions, where the projective symmetry associated with the ends of string may play a key role. In particular, Topological phase transitions may lead to non-Abelian FQH states in double-layer systems which can realize universal quantum computations. The emergent gauge theory in string condensed states may also be the key to understand the novel properties of high temperature superconductors. The PI plans to use a newly developed spinon-dopon theory to gain a more quantitative understanding of high temperature superconductors.A theme of the research is to build a closer connection between the general theory of topological/quantum order and experimental observations, such as those in high temperature superconductors, that appear to defy a conventional explanation. This research may also lead to predictions of new materials and new phenomena. NON-TECHNICAL SUMMARY:This award supports research and education in fundamental theoretical condensed matter physics. The notion of order is an important cornerstone in the foundation of our understanding of the world around us. When liquid with atoms solidifies, the atoms may organize themselves in a periodic array to form a crystal lattice. This is an example of an ordered state of matter; there are many other diverse examples, some more exotic and subtle, in the world around us that can be organized and described by standard theory of phase transitions. The discovery of new materials, like the high temperature superconductors, and states of matter like the quantum Hall phases that arise when electrons are confined to two dimensions in a high magnetic field, has led to questions about fundamental nature of order and whether the concept is more general than our current notion. The PI proposes a specific new kind of order that is not contained in the standard theory of phase transitions, but yet would have significant consequences on how we understand puzzling experiments in various exotic materials. This award supports research that aims to develop a theory of transformations involving these new ordered states and to discover the validity and consequences of this idea. Predictions of new phenomena and possible new states of matter may result from this work; the potential impact on future technologies and other disciplines cannot be estimated. This project also involves students and will help train the next generation of condensed matter theorists.

技术摘要：该奖项支持凝结物理学的理论研究和教育，重点是对物质状态的秩序概念有更深入的了解。基于订单参数，金茨堡 - 兰道理论和群体理论的概念，已经开发了一种针对对称破坏顺序的综合理论。这种理论在凝结物质理论的基础上形成了角石。 PI提出了拓扑顺序和量子顺序的概念，这些概念超出了相变的标准Landau-Ginzburg理论。在该研究项目中，PI计划开发更完整的拓扑/量子顺序理论。具体而言，PI计划将弦网平均场理论应用于现实的量子自旋系统，以识别可能包含非平凡拓扑/量子顺序的材料。将研究弦的末端的强烈波动及其与拓扑状态之间连续过渡的紧密联系。这可能会导致拓扑相变的一般理论，其中与弦的末端相关的投影对称性可能起关键作用。尤其是，拓扑相变可能会导致双层系统中的非亚伯FQH状态，从而实现通用量子计算。琴弦凝结状态中的新兴仪表理论也可能是了解高温超导体的新特性的关键。 PI计划使用新开发的Spinon-Dopon理论来获得对高温超导体的更量化的理解。该研究的主题是在拓扑/量子秩序的一般理论和实验观察中建立更紧密的联系，例如在高温超导体中，似乎无视常规解释。这项研究还可能导致对新材料和新现象的预测。非技术摘要：该奖项支持基本理论凝结物理学的研究和教育。秩序的概念是我们对周围世界的理解的基础。当液体固化液体时，原子可以在周期性阵列中组织起来形成晶格。这是有序状态的一个例子；在我们周围的世界中，还有许多其他不同的例子，一些更奇特和微妙的例子，可以通过标准的相变理论来组织和描述。发现新材料（例如高温超导体）以及物质的状态，例如当电子局限于高磁场中的二维时出现的量子厅阶段，导致了有关秩序的基本性质以及该概念是否为比我们目前的概念更一般。 PI提出了一种特定的新秩序，该秩序不包含在标准的相变理论中，但对我们如何理解各种外来材料的令人困惑的实验会产生重大影响。该奖项支持旨在发展涉及这些新有序国家的转型理论的研究，并发现这一想法的有效性和后果。这项工作可能会导致对新现象和可能物质的新状态的预测；无法估计对未来技术和其他学科的潜在影响。该项目还涉及学生，并将帮助培训下一代冷凝的物质理论家。