Emergent Behavior of Microscopic Model Systems

微观模型系统的涌现行为

• 批准号: 1265593
• 负责人: Steven Kivelson
• 金额: $ 42万
• 依托单位: Stanford University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-09-15 至 2016-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1265593&HistoricalAwards=false
• 关键词: Emergent; Behavior; Microscopic; Model; Systems

TECHNICAL SUMMARYThis award supports theoretical research and education to address long-standing fundamental problems concerning the emergent properties of correlated electron fluids using well-controlled methods of theoretical physics. The PI will investigate properties of electronic systems through a careful analysis of the behavior of simplified models of interacting electrons defined at the lattice scale. The PI will explore generic properties of interacting electronic systems and also attempt to gain insights into material specific features of strongly correlated electronic systems through the inclusion of salient features of the electronic structure of interesting materials. The PI will pursue a three-pronged approach:1. The PI will study the behavior of simplified models of interacting electrons in the weak-coupling limit where controlled, perturbative renormalization group calculations are possible and asymptotically exact results can be obtained. In order to broaden the scope of the physics accessible by these methods, fine-tuned electronic structures will be investigated. This amounts to studying the properties of the phases and phase transitions in the vicinity of quantum multicritical point.2. Near a quantum critical point, electronic properties can often be described by a quantum field theory. A particularly successful use of quantum field theory in correlated electron systems has been the use of Chern-Simons Landau Ginzberg theory to describe quantum Hall systems. This approach implies a profound analogy between the properties of quantum Hall systems and the properties of superconductors. The PI will study the justification and limits of applicability of the Chern-Simons Landau Ginzberg theory, and further explore the consequences of the implied analogy between superconductors and quantum Hall systems.3. Specific aspects of the properties of certain correlated materials can be addressed in terms of models that capture some essential feature of their local electronic structure. The goal is mainly to gain insights into the physics of one experimentally interesting material or another. A good example is provided by the newly discovered antiferromagnetic insulating state of Cs3C60; because it is insulating, it can be studied by expanding about a Mott insulating state in which the number of electrons on each C60 molecule is fixed by the effective Hubbard interaction. Understanding which further interactions dominate in this strongly correlated limit, and how they determine the nature of the ordered states may shed light on the interactions that give rise to superconductivity of this material under pressure, and in the broader family of superconducting materials A3C60, where A is any of a number of alkali metals.Understanding the properties of correlated electron fluids may lead to the ability to exploit novel materials properties to develop new devices and technologies that derive their operating principles from the novel phases and phase competitions that occur in highly correlated electron fluids.NON TECHNICAL SUMMARYThis award supports research and education with an aim to advance understanding of materials with electrons that interact strongly with each other giving rise to new states of electronic matter with interesting and unusual properties. The broad thrust of this research is to gain insights into the nature of the states of electronic matter that emerge in strongly interacting materials. The PI will use simplified models for electrons in materials to examine the relationship between solutions obtained from controlled theoretical methods that assume that electrons are effectively weakly interacting to results obtained by various other methods. Superconductivity is one kind of emergent state of matter which is characterized by the ability of conduct electricity without resistance or loss of energy. The PI will explore an interesting connection between the fundamental physics of superconductors and the seemingly very different state of matter known as the quantum Hall effect. The quantum Hall effect arises when a two-dimensional layer of electrons, which can exist in an artificially layered semiconductor material, is exposed to a perpendicular magnetic field. The PI aims to exploit knowledge of superconductivity to gain new insights into the fundamental physics of the quantum Hall effect.The PI will also investigate the superconducting state that emerges in a material composed of the element cesium and a molecule of carbon containing 60 atoms which exhibits superconductivity under pressure. Experiments reveal properties that are qualitatively similar to those of the high temperature superconductors and other materials with strongly interacting electrons. The PI's study of this recently discovered superconductor may lead to insights into the nature of superconductivity in the high temperature superconductors.Understanding the properties of correlated electron fluids may lead to the ability to exploit novel materials properties to develop new devices and technologies that derive their operating principles from the novel phases and phase competitions that occur in highly correlated electron fluids.

技术摘要这一奖项支持理论研究和教育，以解决有关使用良好控制的理论物理学方法来解决有关相关电子流体的新兴特性的长期基本问题。 PI将通过仔细分析以晶格量表定义的简化电子模型的行为来研究电子系统的性质。 PI将通过包含有趣材料的电子结构的显着特征来探索相互作用的电子系统的通用特性，并试图洞悉密切相关的电子系统的材料特定特征。 PI将采用三管齐下的方法：1。 PI将在弱耦合极限中研究简化的相互作用模型的行为，在受控，扰动重新归一化组计算中，可以获得渐近确切的结果。为了扩大这些方法可访问的物理范围，将研究微调的电子结构。这相当于研究量子多政治点附近的相和相变的特性。2。在量子临界点附近，通常可以通过量子场理论来描述电子特性。量子场理论在相关电子系统中的特别成功使用是使用Chern-Simons Landau Ginzberg理论描述量子厅系统。这种方法意味着量子厅系统的性质与超导体的性质之间的深刻类比。 PI将研究Chern-Simons Landau Ginzberg理论的适用性的理由和限制，并进一步探讨超导体和量子厅系统之间隐含类比的后果3。可以通过捕获其本地电子结构的某些基本特征的模型来解决某些相关材料的特性的特定方面。目标主要是为了了解一种实验有趣的材料或另一种实验性有趣的物理学。新发现的CS3C60的抗铁磁绝缘状态提供了一个很好的例子。由于它是绝缘的，因此可以通过扩展莫特绝缘状态来研究，其中每个C60分子上的电子数量通过有效的哈伯德相互作用固定。理解哪些进一步的相互作用在这种密切相关的极限中占主导地位，以及它们如何确定有序状态的性质可能会揭示相互作用，从而在压力下以及更广泛的超导材料a3c60的家族中引起这种材料的超导性，其中a是多种材料的多种材料，可以启动质子的属性。以及从高度相关的电子流体中发生的新型阶段和阶段竞争中得出其运行原理的技术。《技术摘要》颁发奖项支持研究和教育，目的是通过与彼此相互互动的电子了解材料的理解，从而带来了与彼此相互作用的材料，从而带来了有趣且与众不同的特性。 这项研究的广泛目的是了解在强烈相互作用材料中出现的电子物质状态的性质。 PI将使用材料中电子的简化模型来检查从受控理论方法获得的解决方案之间的关系，这些方法假定电子有效地薄弱地与其他各种其他方法获得的结果相互作用。 超导性是一种新兴物质状态，其特征在于无电或能量损失的电力能力。 PI将探讨超导体的基本物理与看似非常不同的物质状态（称为量子厅效应）之间的有趣联系。当可以在人为分层的半导体材料中存在的二维电子层被暴露于垂直磁场时，就会产生量子大厅的效应。 PI旨在利用超导性知识，以获取对量子厅效应的基本物理学的新见解。PI还将调查在元素剖宫产中出现的超导状态，该状态出现在元素剖宫产和含有60个原子的分子中，该碳含有60个原子，该碳含有60个原子，这些原子在压力下表现出超导导性。实验揭示了与高温超导体和其他具有强相互作用电子的材料的性质。 The PI's study of this recently discovered superconductor may lead to insights into the nature of superconductivity in the high temperature superconductors.Understanding the properties of correlated electron fluids may lead to the ability to exploit novel materials properties to develop new devices and technologies that derive their operating principles from the novel phases and phase competitions that occur in highly correlated electron fluids.