Electrical control of nontrivial textures in magnetic nanostructures

非技术描述：对具有新功能的更小更快的设备的技术需求推动了对物质的非平凡状态的科学探索，这些状态在缩小到几纳米时保持稳定。该项目研究的是skyrmions——一种不平凡的纳米级磁性结构，它不能被磁化的持续演化所湮灭。这种结构可以小到几纳米，这使得传统的显微镜技术很难研究它们，因此对它们的性质或如何在纳米器件中使用它们知之甚少。该项目在纳米结构中使用磁电子测量来获取相关的长度，并研究使用电流局部注入超薄磁性薄膜来创建、操纵和检测skyrmions的可能性。这项研究与本科生和研究生的培训相结合，并为亚特兰大地区迅速发展的更广泛的纳米科学研究、教育和推广工作做出了贡献。技术描述：该项目研究磁天子-磁性材料中的拓扑非平凡状态，它不能通过“平凡”状态的连续变换来获得，因此表现出更高的稳定性，不寻常的动力学特性和对扰动的响应。该研究利用基于垂直各向异性的超薄磁性薄膜的纳米磁性纳米结构和磁电子技术，通过电流产生、表征和操纵skyrmions的静态和动态状态。材料科学和磁性工程被用来实现一个重要的Dzyaloshinskii-Moriya相互作用，能够在没有电流的情况下稳定skyrmions。新的测量方法，如三端霍尔效应，是专门为研究纳米尺度上的现象而设计的，这些现象是现有技术无法达到的。这项研究为拓扑结构对材料性能的影响提供了基本的见解，并为它们的实验探索以及在纳米级磁电子（自旋电子）器件中的可能应用开辟了途径。除了直接培训两名研究生外，该项目的影响还显著增强，因为它支持PI向埃默里大学和更大亚特兰大地区的研究人员提供的免费共享凝聚体和纳米科学研究设施，本科生和高中生的研究参与，以及为亚特兰大科学节和小学科学日等大型特殊活动做出贡献。

Nontechnical description: The technological demand for smaller and faster devices capable of new functionalities drives the scientific exploration of the nontrivial states of matter that remain stable when scaled down to just a few nanometers. The Project studies the skyrmions - nontrivial nanoscale magnetic textures that cannot by annihilated by a continuous evolution of magnetization. Such textures can be as small as a few nanometers, making it difficult to study them by the conventional microscopy techniques, and consequently very little is known about their properties or how they can be used in nanodevices. The Project uses magnetoelectronic measurements in nanofabricated structures to access the relevant length sales, and investigate the possibility to use electrical current locally injected into ultrathin magnetic films to create, manipulate, and detect skyrmions. The research is integrated with the training for undergraduate and graduate students, and contributes to the burgeoning broader nanoscience research, education and outreach efforts in the Atlanta area.Technical description: The Project investigates magnetic skyrmions - topologically nontrivial states in magnetic materials, which cannot be obtained by a continuous transformation of "trivial" states, and thus exhibit higher stability, unusual dynamical characteristics and response to perturbations. The research utilizes nanofabricated magnetic nanostructures based on ultrathin magnetic films with perpendicular anisotropy, and magnetoelectronic techniques to generate, characterize, and manipulate both static and dynamical states of skyrmions by electrical current. Materials science and magnetic engineering are used to achieve a significant Dzyaloshinskii-Moriya interaction capable of stabilizing skyrmions in the absence of current. New measurement approaches, such as three-terminal Hall effect , are designed specifically to investigate phenomena on nanoscale not accessible with the established techniques. This research provides fundamental insight into the effects of topological textures on the material properties, and develops routes for their experimental exploration as well as possible applications in nanoscale magnetoelectronic (spintronic) devices. In addition to directly training two graduate students, the impact of the Project is significantly enhanced by its role in supporting the free shared condensed matter and nanoscience research facilities provided by the PI to researchers at Emory University and in the larger Atlanta area, research involvement of undergraduates and high school students, and contribution the large special events such as the Atlanta Science Festival and the Elementary School Science Day.