Collaborative Research: Correlating Device Performance and Interfacial Properties for Weyl Spintronics

合作研究：关联 Weyl 自旋电子学的器件性能和界面特性

• 批准号: 2031871
• 负责人: Axel Hoffmann
• 金额: $ 29.82万
• 依托单位: University of Illinois at Urbana-Champaign
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-09-15 至 2023-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2031871&HistoricalAwards=false
• 关键词: Collaborative; Research; Correlating; Device; Performance

This grant supports research into understanding new mechanisms by which electrical currents can be used to switch the magnetic orientation of thin magnetic layers in devices for data processing and storage. The use of current pulses to alter magnetism is central to the operating principles of a variety of electronic and spintronic devices. However, new materials systems are needed to reduce the power consumption required for magnetic switching and to enable future device scaling. This award supports fundamental research to identify quantum materials known as Weyl semimetals that enable significant improvements in the efficiency of current-induced magnetic switching. The project will characterize a variety of Weyl semimetals for use in magnetic devices with emphasis on understanding how the switching metrics are influenced by the interfacial properties between the Weyl semimetal and the magnetic layer. The project will also identify how Weyl semimetals can be used to enable switching of perpendicular magnets to facilitate emerging device concepts. The insights into how new quantum materials can reduce power consumption in electronic and magnetic devices may lead to new advances in electronics and computing devices, providing broad societal benefit. The students’ research training enabled by this project will serve to advance the U.S. economic interests by providing them with the experimental skill set needed to contribute to the technological sector.This collaborative project will lay the groundwork for low-power spintronic devices through a series of research activities aimed at providing a detailed understanding of spin-orbit torques generated by Weyl semimetals. The charge-to-spin conversion process will be thoroughly characterized at a series of interfaces between Weyl semimetals and ferromagnetic metals to quantify torque efficiencies. The interfacial properties of these same structures will be characterized using resonant x-ray reflectivity, a technique that allows for both the elemental concentration and magnetization to be determined as a function of depth across the interfaces. The correlations between spin-orbit torque efficiency and the composition and magnetic properties of the interfaces will elucidate the roles of intrinsic (Weyl physics) and extrinsic (non-idealities at the interfaces) contributions to the torques. These activities will yield a thorough understanding of spin-orbit torques across real interfaces in device-based structures fabricated using industry-relevant deposition processes. The research will also identify novel spin-orbit torques, including those associated with an out-of-plane spin polarization, enabled by the unique properties of Weyl semimetals and quantify torque metrics relevant for non-volatile magnetic memory devices and thermally driven stochastic oscillators, where the magnetization of the free magnetic layer is controlled via spin-orbit torques. Through these research activities, this project will advance progress toward employing Weyl semimetals in emerging electronic and spintronic device architectures.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.

该赠款支持研究新机制的研究，可以使用电流来切换设备中薄磁层的磁取向，以进行数据处理和存储。使用当前脉冲来改变磁性是各种电子和自旋设备的运行原理的核心。但是，需要新的材料系统来减少磁开关所需的功耗并实现将来的设备缩放。该奖项支持基本研究，以识别称为Weyl半含量的量子材料，可在电流诱导的磁切换的效率方面进行显着提高。该项目将表征各种Weyl半应用于磁性设备，重点是了解开关指标如何受到Weyl Semimetal和磁层之间的界面特性的影响。该项目还将确定如何使用Weyl Semimetals来启用垂直磁体的切换以促进新兴的设备概念。关于新量子材料如何减少电子和磁性设备的功耗的见解可能会导致电子和计算设备的新进步，从而提供广泛的社会利益。该项目支持的学生的研究培训将通过为他们提供为技术领域做出贡献所需的实验技能集来推动美国的经济利益。该协作项目将通过一系列旨在通过一系列旨在通过Weyl Semimetals生成的旋转型号的详细理解来为低功耗的旋转式设备奠定基础。电荷到旋转转换过程将在Weyl Semimetals和铁磁金属之间的一系列接口上进行彻底表征，以量化扭矩效率。这些相同结构的界面特性将使用谐振X射线反射率来表征，该技术允许在整个接口之间确定元素浓度和磁化的技术。自旋轨道扭矩效率与界面的组成和磁性能之间的相关性将阐明对扭矩的内在（Weyl Physics）和外部外部（非理想性）贡献的作用。这些活动将对使用与行业相关的沉积过程制造的基于设备的结构中的真实接口进行透彻的自旋轨道扭矩。该研究还将确定新型的自旋轨道扭矩，包括与面外旋转极化相关的扭矩，这是由Weyl Semimetals的独特性能和量化与非挥发性磁性内存设备和热驱动的随机振荡器相关的量子的独特性能，而自由磁性层通过旋转式Tor-Orbit Torreqe控制的磁力。通过这些研究活动，该项目将在新兴的电子和自旋设备体系结构中采用Weyl半学的进展。该奖项反映了NSF的法定任务，并通过使用基金会的知识分子优点和更广泛的影响评估标准来评估，被认为是宝贵的支持。