NSF-BSF: Development and Study of Lattice-Derived Flat Band States

非技术摘要：虽然许多传统金属的电子性质可以理解为源于孤立的带电电子的性质，但一些最具根本性的有趣和潜在的技术变革材料却超出了这种范式。这种所谓的相关电子材料可以拥有超出基本预测范式的新兴量子性质，如高温超导。为了发现和开发新的相关材料，最近重新讨论的一个设计原则是创建弱分散(平坦)的电子能带。这些带中的电子相互影响很大，可以为电子关联提供一个天然的平台。该项目旨在以这一研究领域的最新进展为基础，针对、合成和研究特定材料，这些材料旨在基于平坦的电子能带具有强烈的相互作用效应。当前研究计划的更广泛影响包括：(1)通过基础科学创新对社会产生潜在影响，包括基于平板超导体和新型自旋液体材料的量子技术的新平台；(2)通过公众参与讲座、可视化和在线内容，对公众进行量子科学和量子技术主题的教育；(3)通过本科生研究项目吸引针对HBCU的URM学生；(4)通过与魏兹曼科学研究所这个具有凝聚态物理独特能力的项目的合作，增加美国的竞争优势。这种行为是由平带态的猝灭动能引起的，它促进了电子之间的相互作用。这种平坦的频带还可以承载拓扑上的非平凡状态，从而允许潜在的相关和拓扑平台。然而，在多大程度上可以在真实材料中实现足够平坦的能量分散仍然是一个悬而未决的问题。该项目致力于合成和研究新的扁平带材料，重点是新的相关拓扑相、近藤行为以及与自旋液体物理的联系。这项研究的一个关键因素是靶向材料合成和先进光谱之间的密切反馈，以允许检测和晶体工程的平带状态。我们的努力将与本科生开发新测量技术的研究和教育努力相吻合，创造量子概念的可视化以改善量子直觉，以及量子科学教育/推广/URM招募努力。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

Non-Technical Abstract:While the electronic properties of many conventional metals can be understood as arising from the properties of isolated, charge-carrying electrons, several of the most fundamentally interesting and potentially technologically transformative materials are beyond this paradigm. Such so-called correlated electron materials can host emergent quantum properties such as high temperature superconductivity that are beyond basic predictive paradigms. To find and develop new correlated materials, one recently revisited design principle is the creation of weakly dispersing (flat) electron energy bands. Electrons in such bands are strongly influenced by each other and can offer a natural platform for electronic correlation. This project aims to build on recent progress in this research area to target, synthesize, and study specific materials designed to have strong interaction effects based on flat electronic bands. The broader impacts of the present research program include (1) Potential impact on society through fundamental science innovations including new platforms for quantum technology based on flatband superconductors and new spin liquid materials; (2) Education of the public in topics in quantum science and quantum technology through public engagement with lectures, visualizations, and online content; (3) Engagement of URM students targeted at HBCUs via undergraduate research projects; (4) Increasing the competitive advantage of the USA with partnership of this project with unique capabilities for condensed matter physics at the Weizmann Institute of Science.Technical Abstract:Material systems which can host flat electronic bands have been proposed to host exotic electronic behavior. Such behavior arises from the quenched kinetic energy of flat band states that promotes interaction between electrons. Such flat bands can also host topologically non-trivial states, allowing for potential platforms for both correlation and topology. However, the extent to which sufficiently flat energy dispersions can be realized in real materials has remained an open question. This project focuses on the synthesis and study of new flat band materials with a focus on new correlated topological phases, Kondo behavior, and connections to spin liquid physics. A key element of this research is a close feedback between targeted material synthesis and advanced spectroscopy to allow for detection and crystal engineering of flat band states. Our efforts will dovetail with research and educational efforts focused on undergraduate efforts to develop novel measurement techniques, creation of visualizations of quantum concepts to improve quantum intuition, and quantum science education/outreach/URM recruitment efforts.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.