EAGER: Magnonic logic devices with perpendicular magnetic anisotropy

目前基于磁性材料的新型计算器件的发展旨在提高效率并为现有的基于半导体的逻辑器件增加新的功能。磁逻辑器件是一种很有前途的候选器件，它利用纳米结构磁性材料中的磁化波来传递和处理信息，并进行逻辑运算。在载波磁线的连接处，两个或多个波之间的相互作用被用来执行逻辑运算。制造这样的装置需要能够在各种形状的磁线中引导波，并形成磁线结。磁线形状与直线的任何偏差都会导致不必要的波反射和散射，从而极大地限制了磁逻辑器件的性能。拟议的项目将进行一项可行性研究，使用有可能克服这些限制的新型磁性材料。提出了一种优选面外磁化的超薄磁性薄膜的可行性评价方法。这些材料应该允许建造具有不受限制几何形状的磁信息传输总线和逻辑连接的磁逻辑器件。本文的研究将在微波电子学和磁存储技术领域产生更广泛的影响。此外，拟议的研究将成为未来物理学家和工程师的独特训练基地。佐治亚州立大学是少数族裔服务机构，其毕业的少数族裔学生（主要是非裔美国人）比全国任何其他公立或私立学校都多。该计划将促进磁学，光学和纳米技术领域的研究生和本科生教育，并提供各种各样的实验技能，其中纳米制造将具有最广泛的应用范围。本文的研究重点是基于具有垂直磁各向异性的铁磁材料的磁系统的可行性研究。垂直磁各向异性将保证结构的面外磁化，从而支持各向同性正向体积静磁自旋波模式。该项目旨在研究具有垂直磁各向异性的结构铁磁薄膜中的正向体积静磁自旋波传播，并评估将这些结构用于磁逻辑器件的可行性。将使用具有垂直磁各向异性的多层磁性材料。这些材料体系中的自旋波色散不受自旋波导形状变化的显著影响。因此，自旋波的传播不会受到自旋波波导形状变化引起的模式不匹配的影响。基于该结构的磁振逻辑器件将在没有偏置磁场的情况下表现出稳定的运行，而均匀的外部磁场可以用来重新配置它们的运行。提出的项目将导致具有垂直磁各向异性的结构多层薄膜的制造和表征，从而导致对这些系统中的磁化动力学的基本理解。这包括通过铁磁共振测量来评估损耗，以及测量自旋波在可变形状自旋波导和自旋波导结中的传播。微波矢量光谱结合磁光克尔显微实验技术。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Current development of novel computing devices based on magnetic materials is aimed at improving efficiency and adding new functionalities to existing semiconductor based logic devices. One of the promising candidates, magnonic logic device, utilizes waves of magnetization in nano-structured magnetic materials to transfer and process information, and perform logic operations. Interaction between two or more waves in junctions of wave carrying magnetic wires is used to perform logic operations. Building such device requires the ability to guide waves in magnetic wires of various shapes as well as forming magnetic wire junctions. Any deviation of a magnetic wire shape from a straight wire results in unwanted wave reflection and scattering that significantly limits capabilities of magnonic logic devices. The proposed project will perform a feasibility study of using novel magnetic materials that have potential to overcome such limitations. It is proposed to evaluate feasibility of using ultra-thin magnetic films with preferred out-of-plane magnetization. These materials should allow for building magnonic logic devices with unrestricted geometries of magnetic information-carrying busses and logic junctions. The proposed research will have a broader impact in the field of microwave electronics and magnetic memory technology. In addition, the proposed research will be a unique training ground for future physicists and engineers. Georgia State University is the minority serving institution which graduates the largest number of minority students (primarily African-American) than any other public or private school in the country. This program will facilitate graduate and undergraduate student education in the areas of magnetism, optics and nanotechnology and provide a wide variety experimental skills among which nanofabrication will have most broad applications spectrum.The proposed research focuses on the feasibility study of the magnonic systems based on ferromagnetic materials with perpendicular magnetic anisotropy. Perpendicular magnetic anisotropy will ensure the out-of-plane magnetization of structures resulting in support of isotropic forward volume magnetostatic spin wave modes. The project aims at investigating forward volume magnetostatic spin wave propagation in structured ferromagnetic films with perpendicular magnetic anisotropy and evaluating feasibility of using these structures for magnonic logic devices. Multi-layered magnetic materials exhibiting perpendicular magnetic anisotropy will be used. Spin wave dispersion in these material systems is not significantly affected by spin waveguide shape variation. Therefore, propagation of spin waves will not be altered by the mode-mismatching induced by spin waveguide shape variation. Magnonic logic devices based on the proposed structures will demonstrate stable operation in absence of biasing magnetic fields while uniform external magnetic fields can be used to reconfigure their operation. The proposed project will result in fabrication and characterization of structured multilayered films with perpendicular magnetic anisotropy leading to the fundamental understanding of magnetization dynamics in these systems. That includes assessing losses via ferromagnetic resonance measurements, and measuring spin wave propagation in variable shape spin waveguides and spin waveguide junctions. Microwave vector spectroscopy combined with magneto-optical Kerr microscopy experimental techniques will be used.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.