Antiferromagnetic Spin Torque Devices for Terahertz Applications

目的：发展超高速纳米磁性器件，其中利用电流感应自旋扭矩来启动和控制反铁磁体中的超快自旋动力学。智能优点：在反铁磁体中，亚晶格矩通过强交换场耦合，导致自旋波模式的频率在1.0-3.0太赫兹范围内，因此，反铁磁体中的自旋动力学在亚皮秒的时间尺度上演化。反铁磁体有望将磁性设备的运行速度提高2-3个数量级。这项研究旨在开发一类新的纳米级磁性器件，如振荡器和开关，其中电流感应自旋扭矩被用来启动和控制反铁磁自旋阀的自旋动力学。这里提出的研究具有变革性，不仅将为超高速纳米设备打开新的大门，而且还将大大有助于理解反铁磁的基础材料科学和自旋物理。广泛影响：拟议的项目将支持康奈尔大学两名研究生和两名本科生的研究，并为研究生研究提供丰富的领域。该中心将推出一门与纳米科学有关的新的2-3学分的一年级/二年级课程，目的是吸引一年级/二年级学生学习相关学科。PI和研究生将参与康奈尔大学的K-12外展工作，为高中生开发一个带有实验室组成部分的纳米结构入门研讨会。根据美国国际开发署的一项国际发展计划，国际和平协会将帮助在巴基斯坦组织教师培训研讨会。

Objective: Development of very high speed nanoscale magnetic devices in which current induced spin torque is used to initiate and control ultrafast spin dynamics in antiferromagnets. Intellectual Merit: In antiferromagnets the sublattice moments are coupled via strong exchange fields that cause the frequencies of the spin-wave modes to be in the 1.0-3.0 terahertz range, and, consequently, spin dynamics in antiferromagnets evolve on sub-picosecond time-scales. Antiferromagnets offer the promise of increasing the operating speeds of magnetic devices by 2-3 orders of magnitude. The proposed research aims to develop a new family of nanoscale magnetic devices, such as oscillators and switches, in which current induced spin torque is used to initiate and control spin dynamics in antiferromagnetic spin valves. The research proposed here is transformative and would not just open new doors for ultrahigh speed nanoscale devices but also contribute significantly towards the understanding of the fundamental material science and spin physics of antiferromagnets.Broader Impacts: The proposed project will support the research of two graduate students and two undergraduate students at Cornell University and provide a rich set of areas for graduate student research. The PI will introduce a new 2-3 credit hour freshman/sophomore level course related to nanosciences with the goal of attracting freshmen/sophomores to related disciplines. The PI and the graduate students will participate in Cornell's K-12 outreach efforts by developing an introductory workshop on nanostructures, with a laboratory component, for high school students. Under a USAID international development program the PI will help organize teacher training workshops in Pakistan..