CAREER: Experimental Neutron Scattering and Materials-Based Exploration of Spin-Orbital Physics in Intermediate-Bandwidth Quantum Materials

非技术摘要：最近发现的一些具有令人兴奋的新性质的材料中的电子在两个极端之间徘徊：一个是独立的电子基本上相互忽略(如在优质金属中)，另一个是电子相互作用如此强烈，以至于它们促进了集体行为。这些新的所谓的中等带宽系统占据了一种独特的机制，其中电子的原子轨道运动和其本征磁场(或自旋)之间的耦合在产生新的电子行为中起着重要的作用。该项目将支持一个基于中子散射的实验研究计划，探索这些新的自旋-轨道耦合材料的三个关键类别中的基本电子行为：铁基高温超导体、氧化Ir绝缘体和拓扑绝缘体；其中许多材料具有未来能量传输和计算应用的潜力。该项目还将支持解决关键研究问题所需材料的增长，同时满足国家对创造性材料探索的巨大需求。除了支持两名博士生的教育外，该项目还将为未被充分代表的高中实习生和本科生提供动手的、以研究为基础的教育。该项目的研究和教育活动的整合所促进的协同作用也将推进在美国培养下一代中子散射专家的更广泛的目标。技术摘要：该奖项将支持一个基于中子散射的实验研究计划，该计划的目标是了解磁性和竞争秩序在一种新兴的中等带宽材料的电子行为中的作用，在这种材料中，强烈的自旋-轨道耦合效应共同创造了新的性质。这些材料占据了一个独特的耦合区域(U~W)，其中适度的关联可以在它们所产生的基态中产生巨大的影响。这个项目将集中在这三类材料上，其中磁性和轨道自由度被认为起着关键作用：铁磷酸盐高温超导体，新型5d Mott绝缘体，以及扰动的拓扑绝缘体。工作将以项目支持的晶体材料的增长为指导，这些晶体材料是解决关键问题所必需的，同时满足国家对创造性材料探索的巨大需求。除了支持两名博士生的教育外，该项目还将为未被充分代表的高中实习生和本科生提供动手的、以研究为基础的教育。该项目研究和教育活动的整合所促进的协同作用也将推进在美国培训下一代中子散射专家的更广泛目标。

Non-Technical Abstract:The electrons in a number of recently discovered materials with exciting new properties tread a fine line between two extremes: one of independent electrons largely ignoring one another (such as in good metals) and one where electrons interact so strongly with each other that they foster collective behavior. These new classes of so-called intermediate bandwidth systems occupy a unique regime where the coupling between an electron's atomic orbital motion and its intrinsic magnetic field (or spin) plays an important role in generating new electronic behavior. This project will support a neutron scattering-based experimental research program exploring the fundamental electronic behavior in three key classes of these new spin-orbit coupled materials: iron-based high temperature superconductors, iridium oxide insulators, and topological insulators; many of which possess potential for future energy transport and computing applications. The project will also support the growth of materials necessary to attack key research problems while simultaneously addressing the large national need for creative materials exploration. In addition to supporting the education of two PhD students, the project will also provide hands-on, research-based, education to underrepresented high school interns and undergraduates. The synergy fostered by this project's integration of research and educational activities will also advance a broader goal of training the next generation of neutron scattering experts in the United States.Technical Abstract:This award will support a neutron scattering-based experimental research program whose goal is to understand magnetism and competing order's role in the electronic behavior of an emerging class of intermediate bandwidth materials where strong spin-orbital coupling effects conspire to create novel properties. These materials occupy a unique coupling regime (U~W) where modest correlation can exert a dramatic influence within their resulting ground states. This project will focus on three classes of these materials where magnetic and orbital degrees of freedom are thought to play a key role: iron pnictide high temperature superconductors, novel 5d Mott insulators, and perturbed topological insulators. Work will be guided by the project-supported growth of the crystalline materials necessary to attack key issues while simultaneously addressing the large national need for creative materials exploration. In addition to supporting the education of two PhD students, the project will also provide hands-on, research-based, education to underrepresented high school interns and undergraduates. The synergy fostered by this project's integration of research and educational activities will also advance a broader goal of training the next generation of neutron scattering experts in the United States.