Theoretical Investigations of Low Dimensional Quantum Materials

该奖项支持基础理论研究和教育，以促进对材料，特别是二维材料的磁性和超导性的理解。这项研究的部分动机是由于实验发现，两种本身不具有磁性的材料之间的界面存在磁性。PI的目标是开发一个理论框架来研究二维磁性，可以研究具有空间变化磁性的量子力学状态的可能性。这些空间变化的状态具有类似粒子的性质和局部磁方向围绕中心扭曲的结构。这些磁性状态可能构成数据存储新技术或新设备的基础。PI还将研究高度的缺陷和缺陷对超导状态的影响，超导状态可以毫无损失地传输电力。具体来说，PI将研究当不完美和缺陷或无序程度足够高时超导体向绝缘体的转变。PI将研究超导和无序之间相互作用的后果，以促进对绝缘和超导状态本质的理解。这项研究为新材料提供了基本的见解，为控制其特性提供了基础，为潜在的应用提供了基础，对社会有益。这个项目将包括对科学前沿的青年科学家进行培训和指导。该奖项支持理论研究和教育，目的是获得两类低维量子材料的理论见解。第一个项目旨在阐明二维材料中自旋-轨道耦合和逆对称性破缺引起的手性和各向异性交换相互作用。这将有助于更好地理解由此产生的空间调制磁相，如斯基米子晶体，以及它们不同寻常的电子特性。这些研究的动机是最近对薄膜和界面的实验。第二组问题与局域化和超导性之间的相互作用以及由此产生的无序薄膜中的量子相变有关。超导体-绝缘体跃迁是一个长期存在的问题，由于PI最近的理论工作以及隧道和光谱学方面的新实验进展，该问题得到了新的推动。PI将研究高度无序超导体中空间非均匀的电子状态，具有涌现的粒度和不寻常的对绝缘体，这方面的实验证据越来越多。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方法来解决由最近的实验直接引起的问题，目的是获得新的见解并做出可测试的预测。该项目将对凝聚态和材料物理前沿领域的年轻科学家进行培训和指导。PI积极参与俄亥俄州立大学的桥梁项目，以帮助提高少数族裔在物理学领域的参与度。PI将把他的研究纳入教学，并将通过出版物、在国际会议上的演讲和在暑期学校的演讲来传播这些研究。PI还将继续以初高中学生等非科学观众为对象，进行公开演讲和讲座示范。

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.