EAPSI: Detection and Manipulation of the Exotic Magnetic Structures known as Skyrmions in Nanowires for Next Generation Information Storage Applications

提高高密度信息存储系统，如磁性硬盘驱动器，对于计算机和互联网的持续成功是必不可少的。与传统的计算机处理单元（cpu）仍有相当大的改进空间不同，信息存储系统，如磁性硬盘驱动器，正在接近其极限，将需要新的材料来突破这些极限。一种在物理界引起广泛关注的新方法是使用被称为skyrmions的奇异磁畴，它类似于磁泡，可以在其中写入和存储信息。这些吗?磁性泡沫呢?可以比目前在磁性硬盘驱动器中使用的磁域更小，从而可以在更小的区域内存储更多的信息。PI将与中国科学院的田明联教授合作，田明联教授是电子应用领域（包括skyrmins）纳米磁性领域的知名专家。除了田教授的专业知识外，他的实验室还拥有许多仪器，可以用于研究skyrmions及其在单纳米线设备原型中的电子应用。采用化学气相沉积的方法合成了FeGe和Mn1-xFexSi纳米线。每种纳米线的单纳米线器件将在田教授？美国实验室使用他们最先进的聚焦离子束（FIB）。FIB会将Pt导线写入由微操作器拾取的隔离导线上。然后将利用在小组中进行的磁电阻和霍尔效应测量来绘制纳米线中skyrmion相的稳定性。我们自己的物理性能测量系统（PPMS）。由于在纳米线主体中的空间限制，与大单晶相比，skyrmions的稳定性有望提高。一旦绘制出每个系统的相图，就可以研究新的电检测方法。如果这个项目成功了，两种新的纳米线系统将被彻底地研究它们的粒子特性，更重要的是，一种新的、简便的检测单个粒子的方法将被开发出来。能够检测单个skyrmions将是在下一代电子信息存储系统中利用skyrmions的一大步。该奖项隶属于东亚和太平洋暑期研究所项目，由美国国家科学基金会和中国科技部共同资助，支持美国研究生的暑期研究。

Improvement of high density information storage systems, such as magnetic hard drives, is imperative for the continued success of computers and the internet. Unlike computer processing units (CPUs) which still have a fair amount of room for traditional improvement, information storage systems, like magnetic hard drives, are approaching their limits and will need new materials to break through these limits. One new approach that has garnered much attention in the physics community is the use of exotic magnetic domains known as skyrmions which are analogous to magnetic bubbles in which information can be written and stored. These ?magnetic bubbles? can be smaller than the magnetic domains used currently in magnetic hard drives which can allow for more information to be stored in a smaller area. The PI will collaborate with Professor Minglian Tian at the Chinese Academy of Sciences who is a known expert in the field of nanoscale magnetism for electronics applications which includes skyrmions. Along with Tian's expertise, his lab has a number of instruments that allow for the study of skyrmions and their electronic applications in single nanowire device prototypes.Novel nanowires of FeGe and Mn1-xFexSi which are known to host skyrmions have been synthesized via a chemical vapor deposition route. Single nanowire devices of each type of nanowire will be made in Prof. Tian?s lab using their state of the art Focus Ion beam (FIB). The FIB will write Pt electrical leads to an isolated wire picked by a micromanipulator. The stability of the skyrmion phase in the nanowires will then be mapped using magnetoresistance and Hall effect measurements carried out in the group?s own physical properties measurement system (PPMS). The stability of the skyrmions is expected to be increased compared to large single crystals due the spatial confinement of the skyrmions in the nanowire host. Once the skyrmion phase diagram has been mapped for each system, new electrical detection methods will be studied. If the project is successful, two new nanowire systems will have had their skyrmion properties thoroughly studied, and more importantly a novel and facile way to detect single skyrmions will be developed. Being able to detect single skyrmions would be a large step toward utilizing skyrmions in next generation electronic information storage systems. This award under the East Asia and Pacific Summer Institutes program supports summer research by a U.S. graduate student and is jointly funded by NSF and the Ministry of Science and Technology of China.