Collaborative Research: Spin Transport in Nonrelatisvistically Spin-split Antiferromagnets

合作研究：非相对论自旋分裂反铁磁体中的自旋输运

• 批准号: 2316665
• 负责人: Evgeny Tsymbal
• 金额: $ 33.96万
• 依托单位: University of Nebraska-Lincoln
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-08-01 至 2026-07-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2316665&HistoricalAwards=false
• 关键词: Collaborative; Research; Spin; Transport; Nonrelatisvistically

NON-TECHNICAL SUMMARYIn his 1970 Nobel Prize Lecture, Louis Néel famously described antiferromagnets – materials with nearby magnetic moments of atoms being oriented in opposite directions, as interesting but useless. This is due to their vanishing net magnetic moment which makes difficult to control properties of antiferromagnets by an applied magnetic field. Jump forward 50 years, antiferromagnets have emerged as potential replacements for ferromagnets – materials with magnetic moments of atoms being oriented in the same direction, in commercial memory applications. Unlike ferromagnets, antiferromagnets can improve speed and storage density by orders of magnitude. However, harnessing this potential requires the development of efficient information write and read-out protocols for antiferromagnets, which is much more challenging than those used for ferromagnets. This project addresses this challenge by exploiting unique properties of a newly discovered class of antiferromagnets that exhibit an uncompensated magnetic moment along certain crystal directions. While the net magnetic moment of these antiferromagnets remains vanishing, this property allows similar information write and read-out protocols as those used for ferromagnets, provided that the methods to grow single-crystal films of these antiferromagnets have been successfully developed. This collaborative project brings together the experimental and theoretical expertise of the University of Delaware and University of Nebraska-Lincoln with the ultimate goal of developing a memory cell based on this new class of antiferromagnets. The collaborative research will elucidate the unique properties of this new class of antiferromagnets and holds potential to revolutionize information processing and storage. The project will provide valuable training in modern experimental and theoretical methods for early career team members, preparing them for cutting-edge research in materials science. The project emphasizes the inclusion of students from underrepresented minority groups, providing them with exposure to advanced interdisciplinary studies and enriching their professional preparation. The research team will collaborate with industrial researchers offering intellectual stimulus and an important educational component regarding career opportunities in industry. Leveraging the existing program at University of Delaware, the team will outreach to high schools, engaging minority high-school students and inspiring their interest in science and engineering. Additionally, team members will actively participate in the NSF-funded Partnerships for Research and Education in Materials (PREM) program between the University of Nebraska-Lincoln and Tuskegee University. Results of the proposed research will be disseminated to a broader audience via modern multimedia channels including an NSF-supported online resource Funsize Physics.TECHNICAL SUMMARYAntiferromagnets hold great potential for replacing ferromagnets in spintronic device applications due to their orders of magnitude enhanced switching speed and storage density. Realizing this potential requires the development of efficient electric control and detection of the antiferromagnets order parameter, known as the Néel vector, which is much more challenging than the control and detection of the magnetization in ferromagnets. This proposal addresses this challenge by exploiting unique properties of the antiferromagnetic materials that belong to a space group supporting momentum-dependent spin splitting. Among them is RuO2 – the roomtemperature antiferromagnetic metal, exhibiting spin splitting of its electronic bands along certain crystallographic directions. The proposal entails a collaborative effort involving experimental and theoretical research, with the goal of harnessing the advantages offered by these nonrelativistically spin-split antiferromagnets. The ultimate goal is to demonstrate the electrical control and detection of the Néel vector, culminating in the realization of a fully functional antiferromagnetic tunnel junction with a large tunneling magnetoresistance at room temperature. By fundamentally advancing our understanding of the physics and materials science underlying these phenomena, the proposed research will contribute to the technological development of spintronic devices with superior performance. The research team will collaborate with industrial researchers providing intellectual stimulus and valuable insights into potential career opportunities in industry. Additionally, the project will equip early career team members with necessary skills in modern experimental and theoretical methods, essential for conducting research at the frontiers of materials science. The project emphasizes the inclusion of students from underrepresented minority groups, providing them with exposure to advanced interdisciplinary studies and enriching their professional preparation. Leveraging the existing program at University of Delaware, the team will reach out to high schools, engaging minority high-school students and inspiring their interest in science and engineering. Furthermore, team members will actively participate in the NSF-funded Partnerships for Research and Education in Materials (PREM) program between University of Nebraska-Lincoln and Tuskegee University. Results of the proposed research will be disseminated to a broader audience via modern multimedia channels including an NSF-supported online resource Funsize Physics.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.

非技术性总结在1970年的诺贝尔奖演讲中，Louis Néel著名地描述了反铁磁体--附近原子磁矩方向相反的材料，有趣但无用。这是由于它们的净磁矩消失，这使得难以通过施加磁场来控制反铁磁体的性质。向前跳跃50年，反铁磁体已经成为铁磁体的潜在替代品-在商业存储应用中，原子磁矩取向相同的材料。与铁磁体不同，反铁磁体可以将速度和存储密度提高几个数量级。然而，利用这种潜力需要开发高效的反铁磁体信息写入和读出协议，这比铁磁体更具挑战性。该项目通过利用新发现的一类反铁磁体的独特性质来解决这一挑战，这些反铁磁体沿着沿着某些晶体方向表现出未补偿的磁矩。虽然这些反铁磁体的净磁矩仍然消失，但这种性质允许类似于用于铁磁体的信息写入和读出协议，前提是生长这些反铁磁体的单晶薄膜的方法已经成功开发。这个合作项目汇集了特拉华州大学和内布拉斯加州林肯大学的实验和理论专业知识，最终目标是开发基于这种新的反铁磁体的存储单元。这项合作研究将阐明这类新的反铁磁体的独特性质，并有可能彻底改变信息处理和存储。该项目将为早期职业团队成员提供现代实验和理论方法的宝贵培训，为材料科学的前沿研究做好准备。该项目强调吸收代表性不足的少数群体的学生，让他们接触先进的跨学科研究，丰富他们的专业准备。研究团队将与工业研究人员合作，提供智力刺激和有关工业职业机会的重要教育内容。利用特拉华州大学现有的项目，该团队将深入高中，吸引少数民族高中生，激发他们对科学和工程的兴趣。此外，团队成员将积极参与NSF资助的内布拉斯加大学林肯分校和塔斯基吉大学之间的材料研究和教育合作伙伴关系（PREM）计划。拟议的研究结果将通过现代多媒体渠道传播给更广泛的受众，包括NSF支持的在线资源Funsize Physics.Technical SummaryAntiferromagnets拥有巨大的潜力，取代铁磁体自旋电子器件的应用，由于它们的数量级提高开关速度和存储密度。实现这一潜力需要开发有效的电子控制和反铁磁体序参量（称为Néel矢量）的检测，这比控制和检测铁磁体中的磁化强度更具挑战性。该提案通过利用属于支持动量依赖自旋分裂的空间群的反铁磁材料的独特性质来解决这一挑战。其中之一是RuO 2-室温反铁磁金属，表现出自旋分裂的电子带沿着某些晶体方向。该提案需要涉及实验和理论研究的合作努力，目的是利用这些非相对论自旋分裂反铁磁体提供的优势。最终目标是演示Néel矢量的电气控制和检测，最终实现在室温下具有大隧穿磁阻的全功能反铁磁隧道结。通过从根本上推进我们对这些现象背后的物理学和材料科学的理解，拟议的研究将有助于具有上级性能的自旋电子器件的技术发展。该研究团队将与工业研究人员合作，提供智力刺激和对行业潜在职业机会的宝贵见解。此外，该项目将为早期职业团队成员提供现代实验和理论方法方面的必要技能，这对于在材料科学前沿进行研究至关重要。该项目强调吸收代表性不足的少数群体的学生，让他们接触先进的跨学科研究，丰富他们的专业准备。利用特拉华州大学现有的项目，该团队将深入高中，吸引少数民族高中生，激发他们对科学和工程的兴趣。此外，团队成员将积极参与NSF资助的内布拉斯加大学林肯分校和塔斯基吉大学之间的材料研究和教育合作伙伴关系（PREM）计划。拟议研究的结果将通过现代多媒体渠道传播给更广泛的受众，包括NSF支持的在线资源Funsize Physics。该奖项反映了NSF的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。