Physics Near the Mott Transition

技术总结该奖项支持在相互作用的电子系统中发生在Mott金属-绝缘体转变附近的新现象的理论研究和教育。感兴趣的具体领域是连续莫特相变的物理学，以及接近这种相变的量子自旋液体莫特相的物理学。重点是在特定材料的实验或特定微观模型的数值工作的背景下发展理论概念。研究的具体焦点包括：(I)基于更好地理解玻色子的Mott转变的见解的电子Mott转变的新的理论方法，(Ii)无间隙量子自旋液体相理论，重点是识别独特的实验特征(Iii)Mott绝缘体中电子向列有序和自旋液体物理之间的相互作用。项目(I)是探索新的理论方法来解决有关金属演化为Mott绝缘体时电子费米面的命运的基本问题。这是现代量子多体理论中许多问题的关键挑战。项目(Ii)和(Iii)直接受到对弱Mott绝缘体的实验的推动，这些实验发现了量子自旋液体相存在的证据。预计拟议的工作将提供关键的见解，这些见解将有助于解释弱Mott绝缘材料的实验结果，并有助于提出新的建议。所有这些项目都很好地符合了国际和平研究所在发展对重电子临界点附近的非费米液体物理和铜酸盐材料的理解方面的一些长期研究兴趣。该奖项还支持对研究生进行先进理论概念和方法的培训。PI将在可能的情况下，通过麻省理工学院的本科生研究机会计划，让本科生参与研究。国际和平研究所将继续他最近开始的努力，设计讲座，让研究生接触实验方法和现代相关材料的现象学。非技术总结该奖项支持理论研究和教育，这些研究和教育试图预测在一种称为莫特态的特殊绝缘态附近的材料中发生的新现象。标准的理论方法会预测，这些Mott绝缘体实际上是金属的。这些方法不能很好地解释Mott绝缘体中电子之间的强相互作用。当这样做时，金属状态让位于绝缘状态。转变温度最高的高温超导体的母体化合物是Mott绝缘体。给这些材料加上电荷会使它们从Mott状态变为高温超导状态。PI将使用先进的理论工具来理解在莫特态附近发生的拟议的新物质状态。莫特态附近被认为是发现新的物质电子态的明显肥沃区域，并导致标准教科书之外的材料的不同寻常的电子性质。PI还试图预测Mott状态附近的新现象。这是具有高风险因素的基础性研究。这项研究将促进我们对这类材料的电学性质和现象的基本概念的理解。这项研究还可能有助于新设备技术的智力基础，特别是提高控制这些材料加工的能力。该奖项还支持对研究生进行先进理论概念和方法的培训。PI将在可能的情况下，通过麻省理工学院的本科生研究机会计划，让本科生参与研究。PI将继续他最近开始的努力，设计讲座，让研究生接触到实验方法和现代相关材料的现象学。

TECHNICAL SUMMARYThis award supports theoretical research and education on novel phenomena that occur in the vicinity of the Mott metal-insulator transition in interacting electron systems. Specific areas of interest are the physics of continuous Mott transitions, and of quantum spin liquid Mott phases that are proximate to such transitions. The emphasis will be on developing theoretical concepts in the context of either experiments on specific materials or numerical work on specific microscopic models.Specific foci of the research include: (i) new theoretical approaches to the electronic Mott transition based on insights from the better understood Mott transition of bosons,(ii) the theory of gapless quantum spin liquid phases with a focus on identifying unique experimental signatures (iii) the interplay between electronic nematic order and spin liquid physics in Mott insulators. Project (i) is an exploration of new theoretical methods to address fundamental questions concerning the fate of the electronic Fermi surface as a metal evolves into a Mott insulator. This is a key challenge in many problems in modern quantum many-body theory. Projects (ii) and (iii) are directly motivated by experiments on weak Mott insulators that find evidence for the occurrence of quantum spin liquid phases. It is expected that the work proposed will provide key insights that will be useful in interpreting the results from experiments on weakly Mott insulating materials, and would help suggest new ones. All of the projects tie in nicely with some long term research interests of the PI on developing an understanding of non-fermi liquid physics near heavy electron critical points, and in the cuprate materials.This award also supports the training of graduate students in advanced theoretical concepts and methods. The PI will involve undergraduates in the research, when possible, through the Undergraduate Research Opportunities Program at MIT. The PI will continue his efforts, begun recently, to design lectures to expose graduate students to experimental methods and the phenomenology of modern correlated materials.NONTECHNICAL SUMMARYThis award supports theoretical research and education that seeks to predict new phenomena occurring in materials that are near a special insulating state called a Mott state. Standard theoretical methods would predict that these Mott insulators are actually metallic. These methods inadequately account for the strong interactions between electrons in Mott insulators. When this is done, the metallic state gives way to an insulating state. The parent compounds of the high temperature superconductors with the highest transition temperatures are Mott insulators. Adding charges to these materials moves them from the Mott state to the high temperature superconducting state. The PI will use advanced theoretical tools to understand proposed new states of matter that occur near Mott states. The vicinity of a Mott state is thought to be a conspicuously fertile area for the discovery of new electronic states of matter and to lead to unusual electronic properties of materials that lie outside the standard textbooks. The PI also seeks to predict new phenomena near a Mott state. This is fundamental research with high risk elements. The research will advance our fundamental conceptual understanding of the electronic properties and phenomena of this class of materials. The research may also contribute to the intellectual foundations of new device technologies, particularly with increased ability to control the processing of these materials.This award also supports the training of graduate students in advanced theoretical concepts and methods. The PI will involve undergraduates in the research, when possible, through the Undergraduate Research Opportunities Program at MIT. The PI will continue his efforts, begun recently, to design lectures to expose graduate students to experimental methods and the phenomenology of modern correlated materials.