Theoretical Investigations of Low Dimensional Quantum Materials

低维量子材料的理论研究

• 批准号: 1410364
• 负责人: Mohit Randeria
• 金额: $ 28.24万
• 依托单位: Ohio State University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-08-15 至 2018-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1410364&HistoricalAwards=false
• 关键词: Theoretical; Investigations; Low; Dimensional; Quantum

NONTECHNICAL SUMMARYThis award supports fundamental theoretical research and education to advance understanding of magnetism and superconductivity in materials, particularly two dimensional materials. The research is motivated in part by the experimental discovery of magnetism at the interface between two materials that are themselves not magnetic. The PI aims to develop a theoretical framework to investigate magnetism in two dimensions that can investigate the possibility of quantum mechanical states with spatially varying magnetism. These spatially varying states have particle-like properties and a structure where the local direction of magnetism twists around the center. These magnetic states may form the basis of new technologies for data storage or new devices. The PI will also investigate the effect of a high degree of imperfections and defects on the superconducting state, which can transport electric power without loss. Specifically the PI will investigate the transformation of a superconductor into an insulator when the level of imperfections and defects, or disorder, becomes sufficiently high. The PI will study the consequences of the interplay between superconductivity and disorder to advance understanding of the nature of both the insulating and superconducting states. This research contributes fundamental insights into novel materials providing the basis for controlling their properties for potential applications with benefits to society. This project will involve the training and mentoring of young scientists at the frontiers of science.TECHNICAL SUMMARYThe award supports theoretical research and education with a goal to gain theoretical insights into two classes of low-dimensional quantum materials. The first project seeks to elucidate the chiral and anisotropic exchange interactions arising from spin-orbit coupling and broken inversion symmetry in two-dimensional materials. This will lead to a better understanding of the resulting spatially modulated magnetic phases, like skyrmion crystals, and their unusual electronic properties. These investigations are motivated by recent experiments on thin films and interfaces. The second set of problems is related to the interplay between localization and superconductivity and the resulting quantum phase transition in disordered thin films. The superconductor-insulator transition is a long-standing problem that has received renewed impetus from the PI's recent theoretical work and from new experimental progress in tunneling and optical spectroscopy. The PI will investigate the spatially inhomogeneous electronic state in highly disordered superconductors, with emergent granularity and an unusual insulator of pairs, for which there is growing experimental evidence. In both areas the PI's theoretical research will use a mix of analytical and numerical approaches to address questions directly motivated by recent experiments, with the goal of obtaining new insights and making testable predictions.The project will involve the training and mentoring of young scientists in frontier areas of condensed matter and materials physics. The PI is actively involved in the Bridge Program at Ohio State to help enhance under-represented minority participation in physics. The PI will incorporate aspects of his research into teaching, and will disseminate this research through publications, talks at international conferences and lecture at summer schools. The PI will also continue to give public talks and lecture-demonstrations, aimed at non-scientific audiences including middle and high school students.

非技术摘要这一奖项支持基本的理论研究和教育，以提高对材料（尤其是二维材料）的磁性和超导性的理解。这项研究的一部分是由于在两种本身没有磁性的材料之间的界面上发现磁性的实验发现。 PI旨在开发一个理论框架，以在两个维度上研究磁性，以研究具有空间变化的磁性的量子机械状态的可能性。这些在空间上变化的状态具有类似粒子的特性和一个结构，其中磁性的局部方向在中心周围扭曲。这些磁性状态可能构成用于数据存储或新设备的新技术的基础。 PI还将研究高度缺陷和缺陷对超导状态的影响，该状态可以在不会损失的情况下运输电力。具体而言，当缺陷和缺陷或无序的水平变得足够高时，PI将研究超导体向绝缘体的转化。 PI将研究超导性与混乱之间的相互作用的后果，以提高对绝缘状态和超导状态的性质的理解。这项研究为新颖材料提供了基本的见解，为控制其潜在应用的财产提供了基础，并为社会带来了利益。该项目将涉及科学领域的年轻科学家的培训和指导。技术摘要该奖项支持理论研究和教育，其目标是使理论上的见解介绍两类低维量子材料。第一个项目旨在阐明由二维材料中的自旋轨道耦合和破裂的反转对称性引起的手性和各向异性交换相互作用。这将使对所得的空间调制磁相（如天空晶体及其异常的电子特性）有更好的了解。这些研究是由最近在薄膜和界面上进行的实验激励的。第二组问题与无序薄膜中定位和超导性之间的相互作用以及产生的量子相变有关。超导体 - 绝缘体过渡是一个长期存在的问题，它从PI的最新理论工作以及隧道和光谱方案中的新实验进步中获得了新的动力。 PI将在高度无序的超导体中研究空间不均匀的电子状态，具有新兴的粒度和不寻常的成对绝缘子，为此，实验证据越来越多。在这两个领域，PI的理论研究将使用分析和数值方法的混合，以解决最近实验直接动机的问题，目的是获得新的见解并做出可测试的预测。该项目将涉及培训和指导冷凝物质和材料物理学的边境地区的年轻科学家的培训和指导。 PI积极参与俄亥俄州立大学的桥梁计划，以帮助增强代表性不足的少数群体参与物理学。 PI将纳入他在教学上的研究的各个方面，并将通过出版物，在暑期学校的国际会议和演讲中进行谈判来传播这项研究。 PI还将继续进行公开谈判和讲座示范，以中学和高中生在内的非科学观众。