Uncovering the Missing Physics in the Metrology of Spin-Orbit Torques

揭示自旋轨道扭矩计量中缺失的物理现象

• 批准号: 2104268
• 负责人: Daniel Ralph
• 金额: $ 51.37万
• 依托单位: Cornell University
• 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 2024-11-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2104268&HistoricalAwards=false
• 关键词: Uncovering; Missing; Physics; Metrology; Spin

Non-Technical AbstractMagnetic devices offer a combination of virtues for computer memory that no other technology can match – they can retain information with no applied power, they can withstand an unlimited number of writing and reading operations without wearing out, and they can be made fast and high-density. However, widespread applications in electronics will require finding a way to write information to magnetic memories with lower power. Recently, a promising new mechanism has been discovered for controlling magnetic memories very efficiently, known as “spin-orbit torque,” but there is a problem that different experimental methods used to measure the strength of this mechanism often give inconsistent values. This project is investigating what is the missing science that has not been properly taken into account, causing these conflicting results. The practical aim of the research is to enable trustworthy measurements of spin-orbit torques. This will provide the scientific foundation to optimize the next generation of magnetic memory technologies, with the goal that they will enable improved performance and lower energy consumption for applications ranging from machine learning to low-power internet-of-things networks. This project trains graduate and undergraduate students in advanced device fabrication, measurement techniques, and computer modeling along with science communication and other professional skills. Graduates typically find employment in research laboratories of electronics hardware companies. Participants in the project are also active in public outreach programs, in particular a partnership between the Cornell Nanofabrication Facility and 4-H clubs.Technical AbstractRecent advances in understanding the interactions between charge currents, spin currents, and magnets have led to the development of magnetic-memory technologies in which the orientation of magnets is efficiently controlled by torques exerted from spin currents. However, this field faces a fundamental-science puzzle because different experimental techniques used to measure spin-orbit torques (the most-efficient known mechanism for current-driven magnetic manipulation) often give contradictory results. This indicates that the intellectual framework used to analyze these measurements is missing essential physics. This project is performing experiments to test whether the excitation of short-wavelength magnons, heating, nonlinear transport effects, spin currents emitted by ferromagnets, or other yet-to-be recognized effects might explain this missing physics. The ultimate project goal is to establish trustworthy measurement techniques for use in the development of a new generation of magnetic memory devices with improved performance and lower energy consumption, for applications ranging from machine learning to low-power internet-of-things networks. This project trains graduate and undergraduate students in advanced device fabrication, measurement techniques, and computer modeling along with science communication and other professional skills. Participants in the project are also active in public outreach programs, in particular a partnership between the Cornell Nanofabrication Facility and 4-H clubs.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.

磁性器件为计算机存储器提供了一系列其他技术无法比拟的优点--它们可以在不施加电源的情况下保留信息，它们可以承受无限次的写入和阅读操作而不会磨损，并且它们可以制造得更快和更高密度。然而，在电子领域的广泛应用将需要找到一种方法，以较低的功率将信息写入磁存储器。最近，人们发现了一种很有前途的新机制，可以非常有效地控制磁存储器，称为“自旋轨道力矩”，但存在一个问题，即用于测量这种机制强度的不同实验方法往往给出不一致的值。这个项目正在调查什么是缺失的科学，没有得到适当的考虑，导致这些相互矛盾的结果。 研究的实际目的是使自旋轨道扭矩的可靠测量。 这将为优化下一代磁存储器技术提供科学基础，目标是为从机器学习到低功耗物联网网络的应用提供更高的性能和更低的能耗。本计画训练研究生与本科生先进的元件制造、量测技术、电脑模型沿着科学沟通及其他专业技能。毕业生通常在电子硬件公司的研究实验室找到工作。该项目的参与者也积极参与公共宣传计划，特别是康奈尔大学纳米纤维设施和4-H clubs.Technical Abstractive最近的进展，了解电荷电流，自旋电流和磁铁之间的相互作用，导致了磁存储器技术的发展，其中磁铁的方向是有效地控制施加的转矩从自旋电流。然而，这一领域面临着一个基础科学难题，因为用于测量自旋轨道扭矩（电流驱动磁操纵的最有效机制）的不同实验技术往往会给出相互矛盾的结果。这表明用于分析这些测量的知识框架缺少基本的物理学。该项目正在进行实验，以测试短波长磁振子的激发，加热，非线性输运效应，铁磁体发射的自旋电流或其他尚未被认可的效应是否可以解释这种缺失的物理学。该项目的最终目标是建立可靠的测量技术，用于开发新一代磁存储设备，这些设备具有更高的性能和更低的能耗，适用于从机器学习到低功耗物联网网络的应用。本计画训练研究生与本科生先进的元件制造、量测技术、电脑模型沿着科学沟通及其他专业技能。该项目的参与者还积极参与公共外联计划，特别是康奈尔纳米纤维设施和4-H clubs.This奖项之间的伙伴关系反映了NSF的法定使命，并已被认为是值得通过使用基金会的智力价值和更广泛的影响审查标准进行评估的支持。

项目成果

Tuning the Curie temperature of a two-dimensional magnet/topological insulator heterostructure to above room temperature by epitaxial growth

• DOI: 10.1103/physrevmaterials.7.104004
• 发表时间: 2023-08
• 期刊: Physical Review Materials
• 影响因子: 3.4
• 作者: Wenyi Zhou;A. Bishop;Xiyue S. Zhang;K. Robinson;I. Lyalin;Ziling Li;Ryan Bailey-Crandell

Anisotropic Gigahertz Antiferromagnetic Resonances of the Easy-Axis van der Waals Antiferromagnet CrSBr

• DOI: 10.1021/acs.nanolett.2c02124
• 发表时间: 2022-08-04
• 期刊: NANO LETTERS
• 影响因子: 10.8
• 作者: Cham, Thow Min Jerald;Karimeddiny, Saba;Luo, Yunqiu Kelly
• 通讯作者: Luo, Yunqiu Kelly