SGER: Sublithographic Patterning of Nanoscale Spintronic Devices

目的：这项计划的主要技术和科学目标将是制造超高密度的铁磁纳米线阵列，以及它们的磁学和电学特性。这项工作将提供对纳米尺度磁性机制的洞察，并为未来的工作奠定基础，从制造超高密度磁存储器(~0.5Tit/in2)和微波振荡器的相干阵列到开发和探索纳米磁性超材料。技术优点：近年来，控制纳米尺度物质的结构和组成已成为科学界和工程界面临的重大挑战。然而，在这一挑战的广度中，蕴含着从新的角度处理以前难以解决的问题的难得机会。例如，生物启发的有机模板用于低温、特定取向、金属和半导体纳米晶体的合成，以及在有机-无机纳米级混合器件和电路中使用分子材料作为有源层。这一提议提出了另一种这样的趋同，即利用新的亚光刻图形技术与基于自旋转移扭矩机制的自旋电子器件和电路的开发之间的内在兼容性。这种兼容性源于这样一个事实，即自旋转移扭矩的幅度取决于自旋电流密度，因此自然地适合于纳米级的几何形状。同时，超晶格纳米线图案转移(SNAP)技术的发展，用于产生极高密度和良好折射率的大规模平行纳米线阵列(1000‘S导线，间距降至20 nm)，使得能够以接近晶体密度创建多达160,000个结点的交叉开关电路。这项提议的重点将是在Fe、Co和Ni合金中实施这种方法，允许以前所未有的密度制造磁性纳米线，并为尺寸达到超顺磁性极限的磁性隧道结奠定基础。这些结构具有潜在的应用，包括超高密度磁随机存取存储器(MRAM)、电子和光学超材料以及相位相干微波阵列。广泛影响：纳米系统固有的挑战广度的第二个后果是，它需要相应的知识广度来开发给定问题的众多潜在解决方案。从另一个角度考虑这一挑战，纳米科学/纳米技术的研究也提供了一个令人兴奋的机会，为在科学和工程领域接受职业培训的学生和广大公众提供了洞察一些传统上截然不同的学科的机会。因此，该项目将纳入一个综合计划，既为学生进行跨学科研究做准备，又为未来社区的外展工作奠定基础。该计划的中心内容将是开发一门针对高水平本科生和一年级研究生的纳米科学/纳米技术跨学科课程。本课程将分为三个模块，每个模块一个物理、化学和生物模块，每个模块都将介绍纳米科学为什么与适当的学科相关，以及纳米技术的特定方面所隐含的技术和应用。每个模块将由相关领域的讲师专家授课，并将尽可能广泛地发布课程广告，以鼓励来自不同背景的学生报名。由于将每个学生都培养成所有三个学科的专家显然是不现实的，这门课程的目标将是为物理科学提供一种罗塞塔石。更具体地说，向学生介绍他们的同事认为重要的问题和解决方案，以便在他们未来的职业生涯中促进富有成效和成功的跨学科合作。这些活动将为未来高中层面的合作课程开发以及涉及COSI哥伦布科学博物馆的外展项目奠定基础。

SGER: Sublithographic Patterning of Nanoscale Spintronic Devices Objective: The primary technical and scientific objectives of this proposal will be the fabrication of ultra-dense arrays of ferromagnetic nanowires and their magnetic and electronic characterization, respectively. This work will provide insight into the mechanisms of nanoscale magnetism and lay the groundwork for future work ranging from the fabrication of ultra-dense magnetic memories (~ 0.5 TBit/in2) and coherent arrays of microwave oscillators to the development and exploration of nanopatterned magnetic meta-materials.Technical Merit: In recent years, control over the structure and composition of matter at nanoscopic length scales has emerged as a grand challenge facing the scientific and engineering communities. Inherent in the breadth of this challenge, however, is a remarkable opportunity to approach previously intractable problems from a new perspective. Examples include the use of biologically inspired organic templating for the low temperature, orientation specific, synthesis of both metallic and semiconducting nanocrystals and the use of molecular materials as active layers in hybrid organic-inorganic nanoscale devices and circuits. This proposal presents another such convergence, in exploiting an inherent compatibility between novel sublithographic patterning techniques and the development of spintronic devices and circuits based on the spin-transfer torque mechanism. This compatibility arises from the fact that the amplitude of the spin-transfer torque depends on spin current density, and therefore naturally lends itself to nanoscale geometries. In parallel, the development of the superlattice nanowire pattern transfer (SNAP) technique for creating massively parallel arrays of extremely dense and well indexed nanowires (1000's of wires at a pitch down to 20 nm) has allowed for the creation of crossbar circuits of up to 160,000 junctions at nearly crystallographic density. The focus of this proposal will be the implementation of this approach in Fe, Co, and Ni alloys, allowing the fabrication of magnetic nanowires at unprecedented density and laying the groundwork for magnetic tunnel junctions at sizes down to the superparamagnetic limit. These structures have potential applications including ultra-dense magnetic random access memories (MRAM), electronic and optical metamaterials, and phase coherent microwave arrays.Broader Impact: A second consequence of the breadth of the challenge inherent in nanoscale systems is that it requires a commensurate breadth of knowledge to exploit the multitude of potential solutions to a given problem. Considering this challenge from another perspective, the study of nanoscience/nanotechnology also provides an exciting opportunity to provide insight into a number of traditionally distinct disciplines, both for students training in careers in science and engineering and for the public at large. As a result, this program will incorporate an integrated plan to both prepare students for interdisciplinary research as well as lay the foundation for future outreach efforts in the community. The centerpiece of this program will be the development of an interdisciplinary course in nanoscience/nanotechnology aimed at upper level undergraduates and first year graduate students. The course will be broken into three modules, one each for physics, chemistry, and biology, and each module will provide an introduction into both why nanoscience is relevant for the appropriate discipline and the techniques and applications implicit in that particular aspect of nanotechnology. Each module will be taught by an instructor expert in the pertinent area, and the class will be advertised as broadly as possible to encourage students from diverse backgrounds to enroll. As it is clearly not practical to train each student to the level of expert in all three disciplines, the goal of this course will be rather to provide a sort of Rosetta stone for the physical sciences. More specifically, to provide students with an introduction to both the problems and solutions considered important by their colleagues so as to foster productive and successful interdisciplinary collaboration in their future careers. These activities will lay the foundation for future collaborative course development at the high school level, as well as outreach programs involving the Columbus science museum, COSI.