CAREER: Spin-Torque Oscillator Arrays

本研究探讨多层巨磁电阻（GMR）与隧道磁电阻（TMR）自旋力矩振荡器（STO）阵列中静磁自旋波的产生、传播、相互作用与吸收。 随着最近自旋力矩转移和自持振荡器的展示，出现了一类新的振荡器，具有极高的可调谐性和优异的RF性能的潜力。 然而，最近的结果表明，这些新器件的潜力受到单个器件的大相位噪声的限制，这是由于单个器件中存储的能量很小。 一个潜在的解决方案是在一个大的阵列中的许多STO的相位锁定。本研究的重点是STO-STO相互作用的基础科学在多设备阵列的目标奠定可控，可扩展的STO振荡器阵列的基础。具体而言，本研究计划侧重于研究自旋波STO相互作用的基础科学的三个任务：1）多层STO堆栈上的静磁表面波动力学研究，2）STO的静磁表面波受激发射研究，以及3）STO-STO相互作用的空间依赖性和缩放。智力优点：这项研究将发展的基础知识，静磁自旋波在多层GMR/TMR堆栈，如波数的依赖性，衰减，对各种参数的方向性，也是最好的可能的膜配置转移自旋波能量到相邻的STO。此外，对STO与波相互作用的研究还将对单个STO的自旋波发射效率、单个STO对自旋波的散射/吸收/放大、STO在自旋波场中的频率牵引效应以及激发粒子（STO）与连续平面波的非线性相互作用等问题有新的认识。更广泛的影响：这项研究将开发STO阵列，具有低相位噪声振荡器和频谱捷变RF系统的高可调谐性。与这些研究计划相结合，是一个综合的努力，为新的跨学科课程，重点放在设备物理学及其应用的基础知识，虚拟实验室，使地球仪周围的学生探索这些基本概念的创建，并在当地社区的小学和高中学生介绍到磁性和电子的令人兴奋的领域的发展。此外，一个综合的研究和教育计划将为当地社区和地球仪的学生提供直接访问，通过网络部署的虚拟实验室和教育教程来研究纳米器件的基础知识。教育工作将侧重于通过虚拟实验室为学生开发体验式学习活动，使学生能够通过实验和探索学习概念，补充传统的基于讲座的教育方法。

This research investigates magnetostatic spin-wave generation, propagation, interaction and absorption in multi-layer Giant magnetoresistance (GMR) and Tunnel magnetoresistance (TMR) spin-torque oscillator (STO) arrays. With the recent demonstration of spin-torque transfer and self-sustained oscillators, a new class of oscillator has emerged with extreme tunability and potential for excellent RF performance. Recent results have shown, however, that the potential of these new devices is limited by the large phase noise of individual devices due to the small amount of energy stored in a single device. A potential solution is the phase-locking of many STOs in a large array. This research focuses on the fundamental science of STO-STO interaction in multi-device arrays with the goal of laying the foundation for controllable, scalable arrays of STO oscillators. Specifically, this research proposal focuses on three tasks investigating fundamental science of spin-wave STO interaction: 1) Study of magnetostatic surface wave dynamics on multi-layer STO stacks, 2) Study of magnetostatic surface wave stimulated emission by an STO, and 3) Spatial dependence and scaling of STO-STO interactions. Intellectual merit: This research will develop fundamental knowledge about magnetostatic spin wave propagation in multi-layer GMR/TMR stacks such as dependence of wavenumber, decay, directionality on various parameters and also the best possible film configuration for transferring spin wave energy to adjacent STOs. In addition the proposed study on STO-wave interaction will develop new understanding about spin wave emission efficiency of a single STO, spin wave scattering/absorption/amplification by a single STO, frequency pulling effect of a STO under spin wave field as well as non-linear interaction of an excited particle (STO) with a continuous plane wave. Broader impacts: This research will develop STO arrays, with low phase noise oscillators and high tunability for spectrum-agile RF systems. Combined with these research programs is an integrated effort for the development of new interdisciplinary courses that focus on the fundamentals of device physics and their applications, the creation of virtual laboratories that enable students around the globe to explore these fundamental concepts, and the introduction of elementary and high school students in local communities to the exciting field of magnetics and electronics. Furthermore, an integrated research and educational program will provide direct access for students, in local communities and around the globe, to investigate fundamentals of nanoscale devices through web-deployed virtual laboratories and educational tutorials. The educational efforts will focus on developing experiential learning activities for students via virtual labs to enable students to learn concepts through experimentation and exploration, complimenting traditional lecture based educational methods.