Collaborative Research: Large-Amplitude, Easy-Plane Spin-Orbit Torque Oscillators

合作研究：大振幅、简易平面自旋轨道扭矩振荡器

• 批准号: 2236160
• 负责人: Satoru Emori
• 金额: $ 31.15万
• 依托单位: Virginia Polytechnic Institute and State University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-07-01 至 2026-06-30
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2236160&HistoricalAwards=false
• 关键词: Collaborative; Research; Large; Amplitude; Easy

The rapid growth of information and communications technology continues to have an outsized impact on global energy consumption. It is therefore crucial to create new, energy-efficient electronic components that benefit this technology. One such essential device converts a constant voltage input into an oscillating voltage output. The goal of this research is to develop a new class of microscale electronic oscillators, called easy-plane spin-orbit torque oscillators, which are compatible with standard industrial fabrication techniques. By exploiting novel device geometries and recently-discovered phenomenon in ferromagnetic materials, easy-plane spin-orbit torque oscillators could address many problems plaguing conventional oscillators, such as small output signal, nanoscale confinement, and thermal instability. Applications for these new oscillators range from microwave communications to brain-inspired computing. This project also has an outreach component designed to teach K-12 students, especially those from schools underserved in science, how to build simple magnetic motors from household items, with the goal of sparking interest in science at an early age.This research aims to produce foundational knowledge for new spin-orbit torque oscillators based on current-in-plane spin valves, in which the free-layer magnetization precesses at a large cone angle of nearly 90 degrees. The research is inspired by a recent discovery that an electric current in an in-plane magnetized film produces an out-of-plane spin current. This novel spin current can then generate an antidamping torque, driving large-angle precession in the free layer of the spin valve. The first thrust of the research will identify the mechanisms of the out-of-plane spin current and the resulting antidamping torque in spin valves. To this end, first-principles calculations and spin-torque ferromagnetic resonance experiments will be performed on spin valves with systematically varied compositions and structures. The second thrust of the research will determine the critical requirements for stable, large-angle precession in spin valves through micromagnetic simulations and electrical device characterization. A successful outcome will lead to easy-plane oscillators with more than an order of magnitude higher signal and stability compared to existing spin-orbit torque oscillators, owing to a larger swing in magnetoresistance and stronger immunity against thermal fluctuations. Furthermore, the research will produce crucial fundamental knowledge on unconventional spin currents and spin torques, which can control a variety of magnetization dynamics (e.g., perpendicular magnetic switching, superfluid-like exchange flow) in next-generation spintronic devices.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.

信息和通信技术的快速增长对全球能源消耗产生了巨大的影响。因此，至关重要的是创建新的，节能的电子组件，从而使该技术受益。这样的基本设备将恒定电压输入转换为振荡电压输出。这项研究的目的是开发一种新的微观电子振荡器，称为易于平面旋转轨道扭矩振荡器，该振荡器与标准工业制造技术兼容。通过利用新型装置的几何形状和最近发现的铁磁材料现象，易于平面自旋轨道扭矩振荡器可以解决困扰常规振荡器的许多问题，例如小输出信号，纳米级限制和热不稳定性。这些新振荡器的应用范围从微波通信到受脑启发的计算。 This project also has an outreach component designed to teach K-12 students, especially those from schools underserved in science, how to build simple magnetic motors from household items, with the goal of sparking interest in science at an early age.This research aims to produce foundational knowledge for new spin-orbit torque oscillators based on current-in-plane spin valves, in which the free-layer magnetization precesses at a large cone angle of nearly 90 degrees.这项研究的灵感来自最近发现的，即面内磁化膜中的电流会产生平面外旋转电流。然后，这种新颖的自旋电流可以产生防护扭矩，从而在自旋阀的自由层中驱动大角度的进攻。研究的第一个推力将确定平面外旋转电流的机制以及自旋阀中产生的防护扭矩。为此，将在具有系统多样的组成和结构的自旋阀上进行第一原理计算和自旋扭转铁磁共振实验。研究的第二个推力将通过微磁模拟和电气设备表征来确定自旋阀中稳定的大角度进动的关键要求。与现有的自旋轨道扭矩振荡器相比，成功的结果将导致易于平面振荡器，其信号和稳定性高于数量级，这是由于磁力耐药性的挥杆较大，并且针对热波动的免疫力更强。 Furthermore, the research will produce crucial fundamental knowledge on unconventional spin currents and spin torques, which can control a variety of magnetization dynamics (e.g., perpendicular magnetic switching, superfluid-like exchange flow) in next-generation spintronic devices.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 标准。