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

NSF-BSF：晶格衍生平带态的发展和研究

• 批准号: 2104964
• 负责人: Joseph Checkelsky
• 金额: $ 72万
• 依托单位: Massachusetts Institute of Technology
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-12-01 至 2025-11-30
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2104964&HistoricalAwards=false
• 关键词: NSF; BSF; Development; Study; Lattice

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.

非技术摘要：虽然许多传统金属的电子特性可以理解为源自孤立的、带电荷的电子的特性，但一些最有趣且具有潜在技术变革性的材料超出了这一范式。 这种所谓的相关电子材料可以具有超出基本预测范式的新兴量子特性，例如高温超导性。 为了寻找和开发新的相关材料，最近重新审视的一项设计原则是创建弱色散（平坦）电子能带。 这些能带中的电子相互之间影响很大，可以为电子关联提供自然的平台。 该项目旨在以该研究领域的最新进展为基础，瞄准、合成和研究基于平坦电子能带而设计的具有强相互作用效应的特定材料。 目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，包括基于平带超导体和新型自旋液体材料的量子技术新平台； (2) 通过讲座、可视化和在线内容的公众参与，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 学生的参与； (4) 通过与魏茨曼科学研究所具有独特的凝聚态物理能力的项目合作，提高美国的竞争优势。技术摘要：已提出可以承载平坦电子带的材料系统来承载奇异的电子行为。 这种行为是由促进电子之间相互作用的平带态动能猝灭引起的。 这种平带还可以承载拓扑上的非平凡状态，从而为相关和拓扑提供潜在的平台。 然而，在实际材料中能够在多大程度上实现足够平坦的能量色散仍然是一个悬而未决的问题。 该项目专注于新型平带材料的合成和研究，重点关注新的相关拓扑相、近藤行为以及与自旋液体物理学的联系。 这项研究的一个关键要素是目标材料合成和先进光谱学之间的密切反馈，以实现平带态的检测和晶体工程。 我们的努力将与研究和教育工作相结合，重点是本科生开发新颖测量技术、创建量子概念可视化以提高量子直觉，以及量子科学教育/推广/URM 招募工作。该奖项反映了 NSF 的法定使命，并已通过使用基金会的智力优点和更广泛的影响审查标准进行评估，认为值得支持。

项目成果

Large anomalous Hall effect in single crystals of the kagome Weyl ferromagnet Fe3Sn

Kagome Weyl 铁磁体 Fe3Sn 单晶中的大反常霍尔效应

• DOI: 10.1103/physrevb.108.075164
• 发表时间: 2023-08
• 期刊: Physical Review B
• 影响因子: 3.7
• 作者: Belbase, Bishnu P.;Ye, Linda;Karki, Bishnu;Facio, Jorge I.;You, Jhih;Checkelsky, Joseph G.;van den Brink, Jeroen;Ghimire, Madhav Prasad
• 通讯作者: Ghimire, Madhav Prasad

Three-dimensional flat bands in pyrochlore metal CaNi2

烧绿石金属 CaNi2 中的三维平带

• DOI: 10.1038/s41586-023-06640-1
• 发表时间: 2023-11
• 期刊: Nature
• 影响因子: 64.8
• 作者: Wakefield, Joshua P.;Kang, Mingu;Neves, Paul M.;Oh, Dongjin;Fang, Shiang;McTigue, Ryan;Frank Zhao, S. Y.;Lamichhane, Tej N.;Chen, Alan;Lee, Seongyong;et al
• 通讯作者: et al

Spin wavepackets in the Kagome ferromagnet Fe 3 Sn 2 : Propagation and precursors

Kagome 铁磁体 Fe 3 Sn 2 中的自旋波包：传播和前驱体

• DOI: 10.1073/pnas.2220589120
• 发表时间: 2023-05-23
• 期刊: Proceedings of the National Academy of Sciences
• 作者: Lee, Changmin;Sun, Yue;Ye, Linda;Rathi, Sumedh;Wang, Kevin;Lu, Yuan-Ming;Moore, Joel;Checkelsky, Joseph G.;Orenstein, Joseph
• 通讯作者: Orenstein, Joseph