ERI: Hybrid magnonic optics for data processing applications

该奖项全部或部分由2021年美国救援计划法案（公法117-2）资助。现代通信和数据处理依赖于光或微波等电磁波。利用光的引导和操纵可以通过使用诸如纤维、透镜、棱镜和镜子之类的众所周知的元件来完成。为了有效地工作，它们的尺寸不能小于所用波的波长，这大大限制了微波和光学器件的小型化能力。如果使用较短的波来编码信息，这种情况可能会得到显著改善。该项目的重点是磁性材料的研究，其中微波波长可以显着缩短。该提案的主要目标之一是在磁系统中构建光学元件，以推动现有技术朝着创建节能和超紧凑微波设备的方向发展。另一个目标是创建模仿人脑神经元功能的magnonic元素。这种设备是神经形态计算机的核心元素，可以用于广泛的模式识别任务。在这个项目的框架内，首席研究员将教育新一代的学生在现代微波和光学测量技术，材料工程和纳米纤维，这将致力于进一步发展美国的科学，工程和技术劳动力。该项目的重点是基于自旋波的物理数据处理设备的开发。自旋波是磁有序材料中磁化强度的本征激发。它们的性质强烈地依赖于磁化顺序，这可以通过施加的偏置磁场来控制。该提议的基本原理是使用由具有不同磁化强度和高各向异性的其他材料的相邻磁性层产生的局部场来控制磁管道中的自旋波色散。基于这一原理，各种自旋波光学元件，如透镜，棱镜，磁振子晶体，频率复用器和傅立叶光学器件将被设计，创建和优化。通过使用具有不同磁化模式的相邻磁性元件，可以实现复杂的波散射几何形状，为设备功能的定制创造了广泛的可能性。这种系统的主要优点之一是可以通过外部磁场重新磁化整个结构来调整这些图案，而无需改变层的几何形状。将特别注意缩小这些设备的规模，同时保持其特性。自旋波固有的非线性将用于构建具有阈值行为的光学元件，这是创建人工神经元所需的。在该提案的最后阶段，将结合这些发展来实现非线性自旋波水库计算设备原型。所描述的研究目标将通过布里渊光散射技术、微波表征以及数值微磁模拟对拟议原型进行深入的实验研究来实现。总的来说，拟议的研究将促进对磁性材料中线性和非线性波物理学的理解，并导致创造一种新的超紧凑节能微波数据处理设备。该奖项反映了NSF的法定使命，并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。

This award is funded in whole or in part under the American Rescue Plan Act of 2021 (Public Law 117-2).Modern communications and data processing rely on electromagnetic waves such as light or microwaves. Guiding and manipulation with light can be done by using such well-known elements as fibers, lenses, prisms, and mirrors. For effective operation, their size cannot be made smaller than the wavelengths of the used wave, which significantly limits the miniaturization capabilities of microwave and optical devices. The situation could be significantly improved if shorter waves will be used for encoding information. This project is focused on the investigation of magnetic materials, in which microwave wavelengths can be made significantly shorter. One of the main goals of this proposal is to build optical elements in magnetic systems to advance the existing technology towards the creation of energy-efficient and ultra-compact microwave devices. Another goal is to create magnonic elements mimicking the functionality of human brain neurons. Such devices are the core elements of neuromorphic computers, which could be used in a broad range of pattern recognition tasks. In the frame of this project, the principal investigator will educate the new generation of students in modern microwave and optical measurements techniques, materials engineering, and nanofabrication, which will commit to further development of the U.S. science, engineering, and technology workforce.The project focuses on the development of spin-wave-based physical data processing devices. Spin waves are eigen-excitations of magnetization in magnetically ordered materials. Their properties strongly depend on the magnetization order, which can be controlled by the applied bias magnetic field. The rationale of the proposal is the control of spin-wave dispersion in magnetic conduits using local fields produced by adjacent magnetic layers of other material with different magnetization and high anisotropy. Based on this principle, various spin-wave optical elements, such as lenses, prisms, magnonic crystals, frequency multiplexers, and Fourier-optics devices will be designed, created, and optimized. By using adjacent magnetic elements with different magnetization patterns, complicated wave-scattering geometries could be realized, creating broad possibilities for customization of the device functions. One of the key benefits of such a system is the possibility to tune these patterns by remagnetizing the whole structure by external field without a need to change the geometry of the layer. Special attention will be devoted to downscaling these devices while preserving their characteristics. Spin-waves intrinsic nonlinearity will be used to build optical elements with threshold-like behavior, which is required for the creation of an artificial neuron. In the last stage of the proposal, the developments will be combined for the realization of the nonlinear spin-wave reservoir computing device prototype. The described research aims are going to be achieved by intense experimental study of the proposed prototypes by means of Brillouin light scattering technique together with microwave characterization as well as numerical micromagnetic simulations. Overall, the proposed research will advance understanding of the physics of linear and nonlinear waves in magnetic materials as well result in the creation of a new class of ultra-compact energy-efficient microwave data processing 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.