CAREER: Emergent Phases of Correlated Electrons in Materials with Spin-Orbit Coupling and Magnetic Frustration

职业：具有自旋轨道耦合和磁挫败的材料中相关电子的涌现相

• 批准号: 1255544
• 负责人: Natalia Perkins
• 金额: $ 45.2万
• 依托单位: University of Wisconsin-Madison
• 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: 2013-08-15 至 2015-02-28
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1255544&HistoricalAwards=false
• 关键词: CAREER; Emergent; Phases; Correlated; Electrons

TECHNICAL SUMMARYThis award supports theoretical on novel quantum phases that arise from the collective behavior of correlated electrons in the presence of strong spin-orbit coupling and frustration. The main focus is on 5d transition metal oxides, such as iridates and osmates, in which spin-orbit-coupling is comparable to, or larger than Coulomb energy. Specific 5d transition metal oxide systems have recently attracted a lot of theoretical and experimental attention because of unusual hierarchy of interactions, extended nature of 5d-orbitals, and high sensitivity to crystal fields. Because of these properties 5d systems are candidate materials for the realization of various emergent quantum phases, such as spin liquids, topological insulators, Weyl semimetals, and novel magnetically ordered Mott insulators.The PI aims to develop and analyze effective spin-orbital models which describe the low-energy physics of correlated systems in the presence of strong spin-obit coupling. The PI plans to study the ground state phase diagrams of these models and identify the nature of possible quantum states and phase transitions with an emphasis on studying finite temperature properties of these models, as the presence of anisotropic interactions in these models significantly affects the nature of finite temperature phase transitions. The PI will also study the effects of doping, as this can give rise to high-temperature superconductivity in these systems.Another thrust of the research is devoted to the analysis of elementary excitations in systems with strong spin-orbit-coupling. The PI plans to use a new computational framework to study quasiparticles in the magnetically ordered ground state in materials with strong spin-orbit-coupling, which she has recently developed. The method is quite useful for interpreting data obtained by the resonant inelastic x-ray scattering, which currently is the most effective tool to study the dispersion of elementary magnetic excitations across the whole Brillouin zone. The PI will also apply the method to analyze the effects of strong spin-orbit-coupling in Raman scattering from iridates and osmates. The PI?s ultimate goal is to provide a better understanding and description of existing experimental data and to generate verifiable predictions for future experiments.This project will be carried out in collaboration with collaborators from Europe and Japan. The collaboration brings an international dimension to the education of graduate students involved in the project. The PI plans to develop an advanced course in strongly correlated phenomena in complex materials and systems with special emphasis on new trends in magnetism and transport phenomena. In collaboration with other local faculty, the PI will create a Wisconsin Winter School on Modern Condensed Matter and Quantum Information and will organize short-term courses of condensed matter physics. This Winter School will introduce young researchers to various specific problems in the field and will also improve collaboration between faculty, students, and postdocs from different campuses of the University of Wisconsin System. The PI will also deliver a series of annual lectures for High School students and Physics lectures and seminars in support of the physics department outreach activity. The lectures will include the topics of quantum mechanics, computer science, and the future of material science.NONTECHNICAL SUMMARY This award supports theoretical and computational research and educational activities aimed at advancing our understanding of materials, in which the electron spin, an intrinsic quantum mechanical property of electrons, and the motion of the electron in a material strongly interact with each other, known as the spin-orbit interaction. The relevant materials are oxides that include transition metals, specifically iridium and osmium, in which the way the atoms are organized in space leads to a spin or spatial distribution of electrons which can occur in many nearly equivalent and hence, competing ways. The PI will focus on the case where the spin-orbit interaction dominates the familiar Coulomb interaction between electrons that arises from the electron charge. Achieving a theoretical understanding of the resulting properties of these materials in which the interactions among electrons lead to strong correlations in their motions is challenging. Interest in these systems stems in part from the richness of their novel properties: the unexpected variety of ways the electrons organize themselves, which leads, for example, to various forms of magnetism, the transformations among these states, and new phenomena that can arise in these iridium and osmium bearing materials. The PI will use theoretical and computational methods to investigate the physical properties of these transition metal oxides, predict new effects in these materials, and contribute to understanding the intriguing results of experiments. This project will be carried out in collaboration with collaborators from Europe and Japan. The collaboration brings an international dimension to the education of graduate students involved in the project. The PI plans to develop an advanced course in strongly correlated phenomena in complex materials and systems with special emphasis on new trends in magnetism and transport phenomena. In collaboration with other local faculty, the PI will create a Wisconsin Winter School on Modern Condensed Matter and Quantum Information and will organize short-term courses of condensed matter physics. This Winter School will introduce young researchers to various specific problems in the field and will also improve collaboration between faculty, students, and postdocs from different campuses of the University of Wisconsin System. The PI will also deliver a series of annual lectures for High School students and Physics lectures and seminars in support of the physics department outreach activity. The lectures will include the topics of quantum mechanics, computer science, and the future of material science.

该奖项支持在存在强自旋轨道耦合和挫折的情况下，由相关电子的集体行为产生的新型量子相的理论研究。主要焦点是5d过渡金属氧化物，如铱酸盐和锇酸盐，其中自旋-轨道耦合相当于或大于库仑能量。特殊的5d过渡金属氧化物体系由于其不同寻常的相互作用层次、5d轨道的扩展性质以及对晶体场的高灵敏度，近年来引起了许多理论和实验的关注。由于这些特性，5d体系是实现各种涌现量子相的候选材料，如自旋液体、拓扑绝缘体、Weyl半金属和新型磁有序莫特绝缘体。PI旨在开发和分析有效的自旋轨道模型，该模型描述了存在强自旋轨道耦合的相关系统的低能物理。PI计划研究这些模型的基态相图，并确定可能的量子态和相变的性质，重点研究这些模型的有限温度特性，因为这些模型中各向异性相互作用的存在显着影响了有限温度相变的性质。PI还将研究掺杂的影响，因为这可以在这些系统中产生高温超导性。本研究的另一个重点是对强自旋-轨道耦合系统的基本激励进行分析。PI计划使用一个新的计算框架来研究她最近开发的具有强自旋-轨道耦合的材料中处于磁有序基态的准粒子。该方法对于解释由共振非弹性x射线散射获得的数据非常有用，这是目前研究整个布里渊区基本磁激励色散的最有效工具。PI还将应用该方法分析强自旋-轨道耦合对铱酸盐和锇酸盐拉曼散射的影响。π吗?我们的最终目标是对现有的实验数据提供更好的理解和描述，并为未来的实验产生可验证的预测。该项目将与来自欧洲和日本的合作者合作进行。此次合作为参与该项目的研究生教育带来了国际化的维度。PI计划开设复杂材料和系统强相关现象的高级课程，特别强调磁性和输运现象的新趋势。PI将与其他当地教师合作，创建威斯康星州现代凝聚态物质和量子信息冬季学校，并组织凝聚态物理的短期课程。这个冬季学校将向年轻的研究人员介绍该领域的各种具体问题，并将改善威斯康星大学系统不同校区的教师、学生和博士后之间的合作。PI还将为高中学生提供一系列的年度讲座和物理讲座和研讨会，以支持物理系的外展活动。讲座内容将包括量子力学、计算机科学和材料科学的未来。该奖项支持理论和计算研究以及旨在提高我们对材料的理解的教育活动，其中电子自旋，电子固有的量子力学性质，以及材料中电子的运动彼此强烈相互作用，称为自旋轨道相互作用。相关材料是氧化物，包括过渡金属，特别是铱和锇，其中原子在空间中的组织方式导致电子的自旋或空间分布，这可能以许多几乎相等的方式出现，因此，竞争的方式。PI将关注自旋轨道相互作用主导电子之间的库仑相互作用的情况，这种相互作用是由电子电荷引起的。在这些材料中，电子之间的相互作用导致它们的运动具有很强的相关性，从理论上理解这些材料的最终性质是具有挑战性的。对这些系统的兴趣部分来自于它们丰富的新特性：电子自我组织的方式出乎意料的多样化，例如，导致各种形式的磁性，这些状态之间的转换，以及这些含铱和锇材料中可能出现的新现象。PI将使用理论和计算方法来研究这些过渡金属氧化物的物理性质，预测这些材料的新效应，并有助于理解有趣的实验结果。该项目将与来自欧洲和日本的合作者合作进行。此次合作为参与该项目的研究生教育带来了国际化的维度。PI计划开设复杂材料和系统强相关现象的高级课程，特别强调磁性和输运现象的新趋势。PI将与其他当地教师合作，创建威斯康星州现代凝聚态物质和量子信息冬季学校，并组织凝聚态物理的短期课程。这个冬季学校将向年轻的研究人员介绍该领域的各种具体问题，并将改善威斯康星大学系统不同校区的教师、学生和博士后之间的合作。PI还将为高中学生提供一系列的年度讲座和物理讲座和研讨会，以支持物理系的外展活动。讲座内容将包括量子力学、计算机科学和材料科学的未来。