Collaborative Proposal: Physics of Ferromagnetic Nanostructures in a Circular Field

****技术摘要****这个由霍利奥克山学院和马萨诸塞大学阿默斯特分校合作的项目，通过在原子力显微镜尖端施加电流产生的局部圆形场，以及在AFM尖端或制造的引线上施加电流脉冲，来探索铁磁纳米结构中的磁态。这些技术将允许对磁盘的涡旋和涡旋核进行单独控制，以及对导线中单个畴壁（DWs）的操作，以研究不同类型DWs的物理性质及其之间的相互作用。据预测，在应用的圆形场中，当涡旋状态切换时，足够薄的铁磁纳米环具有由成对的360度畴壁（DWs）组成的独特状态。了解dw和圆形纳米结构将为下一代数据存储设备提供信息。这项工作将涉及芒特霍利奥克学院的本科生，以及博士后和研究生，促进两个机构之间的频繁互动。此外，将为K12教师和附近的斯普林菲尔德技术社区学院建立的项目开发有关磁力的课程材料，并将创建一个当地的科学咖啡馆，让科学技术专家在非正式的环境中与公众交谈。****非技术摘要****计算机硬盘驱动器目前以二进制“1”和“0”存储信息，这些信息被编码为有效的小条形磁铁，北极或南极指向上方。有很多改进数据存储设备的建议，包括圆形纳米结构，可以在一个独特的顺时针或逆时针“漩涡”状态下存储“1”和“0”，以及将信息存储在相反磁化部分之间形成的畴壁中的设备。传统上，磁化是用均匀外场来研究的。这个由Mount Holyoke学院（MHC）和马萨诸塞大学阿默斯特分校（UMass）合作的项目，使用一种最新开发的技术，通过精确定位一根微小的电线，并通过电流通过产生磁场的电线，产生局部不均匀的圆形磁场，从而研究磁态。这项工作将涉及芒特霍利奥克学院的本科生，以及博士后和研究生，促进两个机构之间的频繁互动。有关磁学的课程材料将由K12教师和附近的斯普林菲尔德技术社区学院开发，并将创建一个科学咖啡馆，让科学技术专家在非正式的环境中与公众交谈。

****Technical Abstract****This collaborative project between Mount Holyoke College and the University of Massachusetts, Amherst, explores magnetic states in ferromagnetic nanostructures by applying a local circular field generated by passing current through the tip of an atomic force microscope, as well as applying current pulses through the AFM tip or fabricated leads on the sample. These techniques will allow for separate control over the vortex and vortex core of magnetic disks, as well as manipulation of individual domain walls (DWs) in wires to investigate the physics of different types of DWs and interactions between them. Sufficiently thin ferromagnetic nanorings are predicted to have unique states that consist of pairs of 360 degrees domain walls (DWs) when switching between vortex states in an applied circular field. Understanding DWs and circular nano-structures will inform the next generation of data storage devices. This work will involve the undergraduate women at Mount Holyoke College, as well as post-docs and graduate students, fostering frequent interaction between the two institutions. Furthermore, curricular material on magnetism will be developed for established programs with K12 teachers and the nearby Springfield Technical Community College, and a local Science Café will be created, bringing experts in science and technology to speak with the general public in an informal setting.****Non-Technical Abstract****Computer hard drives presently store information in binary bits of "1" and "0" that are encoded in what are effectively little bar magnets with either the north or south pole pointing up. There are a variety of proposals for improved data storage devices, including circular nanostructures that could store the "1" and "0" in a unique clockwise or counterclockwise "vortex" state, and devices that store information in the domain walls that form between oppositely magnetized sections of a wire. Traditionally, magnetization has been studied using uniform external fields. This collaborative project between Mount Holyoke College (MHC) and the University of Massachusetts, Amherst (UMass), uses a recently developed technique to investigate magnetic states by generating a local non-uniform, circular magnetic field by precisely positioning a tiny wire and passing a current through the wire that creates the magnetic field. This work will involve the undergraduate women at Mount Holyoke College, as well as post-docs and graduate students, fostering frequent interaction between the two institutions. Curricular material on magnetism will be developed for established programs with K12 teachers and the nearby Springfield Technical Community College and a Science Café will be created, bringing experts in science and technology to speak with the general public in an informal setting.