FRUSTRATED MAGNETISM IN SPIN-ORBIT COUPLED MATERIALS

自旋轨道耦合材料中的受挫磁性

• 批准号: 1206774
• 负责人: Oleg Starykh
• 金额: $ 27万
• 依托单位: University of Utah
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-09-01 至 2016-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1206774&HistoricalAwards=false
• 关键词: FRUSTRATED; MAGNETISM; SPIN; ORBIT; COUPLED

TECHNICAL SUMMARYThis award supports theoretical research aimed at achieving a fundamental understanding of various frustrated quantum magnets, both of localized and itinerant kind. It consists of three research directions:(1) The first addresses the unusual features of the magnetization process of frustrated antiferromagnets, and in particular the appearance and the stability of magnetization plateau phases in the system of strongly correlated, but itinerant, electrons on a triangular lattice. The PI and his group will study the transition to the metallic state at fixed magnetization and explore the sensitivity of the quantum critical point separating the co-planar and cone phases with respect to exchange anisotropy and interlayer interactions between spins as well as the magnitude of the microscopic spin. (2) The second direction is devoted to exploiting spin-orbital interactions, which are always present in experimental materials of interest, in order to probe fractionalized spinon excitations of the spin-liquid ground states. (3) The third direction consists of the development and application of a novel numerical approach, called Diagrammatic Monte Carlo, to finite temperature properties of frustrated antiferromagnets. This method is free from the finite-size effect which severely restricts more traditional numerical approaches and is expected to open a new route for describing the cooperative paramagnetic states of experimentally relevant materials.This award also supports the PI's educational activities that are closely tied with the outlined research plan. These include the training and education of graduate and undergraduate students in analytical and numerical condensed matter physics. In addition, the PI will develop a novel graduate course, Physics of Modern Materials, that is aimed at exposing the students to newest developments in condensed matter physics. The PI will continue to maintain a research website which summarizes the main research developments in terms accessible to graduate students as well as to professional colleagues.NON-TECHNICAL SUMMARYThis award supports theoretical research aimed at achieving a fundamental understanding of "frustrated" magnetic materials. Frustration is a technical term used to describe situations when different microscopic elements, such as microscopic magnetic moments inside a magnetic material, are unable to find equilibrium configurations in which all members of the ensemble have minimal possible energy contributions. Thus, a finite fraction of microscopic moments can be viewed as being constantly "on the move" to look for a more satisfactory arrangement, which never materializes. This situation leads to the appearance of very unusual magnetic structures and peculiar quantum dynamics which persists over a wide range of temperatures, magnetic fields and other experimentally controlled external parameters. The PI will use analytical methods and develop new numerical techniques to explore a variety of fundamentally important frustrated magnet systems. This award also supports the PI's educational activities that are tied closely with the outlined research plan. These include the training and education of graduate and undergraduate students in analytical and numerical condensed matter physics. In addition, the PI will develop a novel graduate course, Physics of Modern Materials, that is aimed at exposing the students to newest developments in condensed matter physics. The PI will continue to maintain a research website which summarizes the main research developments in terms accessible to graduate students as well as to professional colleagues.

技术概述：该奖项支持理论研究，旨在实现对各种局部和流动量子磁体的基本理解。它包括三个研究方向：(1)第一个解决了受挫反铁磁体磁化过程的不寻常特征，特别是在三角形晶格上强相关但流动的电子系统中的磁化平台相的外观和稳定性。PI和他的团队将研究在固定磁化下向金属态的转变，并探索分离共面相和锥相的量子临界点的灵敏度，以及自旋之间的交换各向异性和层间相互作用以及微观自旋的大小。(2)第二个方向致力于利用自旋-轨道相互作用，这种相互作用总是存在于感兴趣的实验材料中，以探测自旋-液体基态的分形自旋激发。(3)第三个方向包括开发和应用一种新的数值方法，称为图解蒙特卡罗，用于研究受挫反铁磁体的有限温度特性。该方法摆脱了传统数值方法的有限尺寸效应，有望为描述实验相关材料的协同顺磁状态开辟一条新的途径。该奖项还支持PI的教育活动，这些活动与概述的研究计划密切相关。这些包括研究生和本科生在分析和数值凝聚态物理方面的培训和教育。此外，PI将开发一门新的研究生课程，现代材料物理学，旨在让学生接触凝聚态物理的最新发展。PI将继续维持一个研究网站，以研究生和专业同事可以访问的方式总结主要的研究进展。该奖项支持旨在实现对“受挫”磁性材料的基本理解的理论研究。挫折是一个技术术语，用于描述不同微观元素的情况，例如磁性材料中的微观磁矩，无法找到所有成员具有最小可能能量贡献的平衡构型。因此，微观时刻的有限部分可以被视为不断“移动”以寻找更令人满意的安排，而这种安排永远不会实现。这种情况导致了非常不寻常的磁结构和特殊的量子动力学的出现，这些量子动力学在很宽的温度、磁场和其他实验控制的外部参数范围内持续存在。PI将使用分析方法和开发新的数值技术来探索各种重要的受挫磁体系统。该奖项还支持PI的教育活动，这些活动与概述的研究计划密切相关。这些包括研究生和本科生在分析和数值凝聚态物理方面的培训和教育。此外，PI将开发一门新的研究生课程，现代材料物理学，旨在让学生接触凝聚态物理的最新发展。PI将继续维持一个研究网站，以研究生和专业同事可以访问的方式总结主要的研究进展。