Skyrmions in antiferromagnetic and highly anisotropic environments

反铁磁和高度各向异性环境中的斯格明子

• 批准号: 403502758
• 负责人: Professor Dr. Matthias Bode
• 金额: --
• 依托单位: Lehrstuhl für Experimentelle Physik II
• 依托单位国家: 德国
• 项目类别: Priority Programmes
• 财政年份: 2018
• 资助国家: 德国
• 起止时间: 2017-12-31 至 2022-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/403502758?language=en
• 关键词: Skyrmions; antiferromagnetic; highly; anisotropic; environments

Within this project, we will make use of the atomic-resolution capabilities of spin-polarized scanning tunneling microscopy (SP-STM) to (i) prepare and directly image skyrmions in antiferromagnetic (AFM) films, (ii) to study highly anisotropic chiral spin structures and magnetic solitons in yet unexplored strongly anisotropic transition metal oxides (TMO), and (iii) to probe how magnetic domain walls and skyrmions interact with electric currents. Towards these goals, we will image the real-space spin structure with atomic resolution and study the impact of external stimuli, such as global external magnetic fields or local electric field pulses applied by the STM tip. Furthermore, we will investigate the effects of single molecular or atomic defects on the formation, size, shape, and mobility of magnetic skyrmions. WP(i) — Skyrmions with a ferromagnetic exchange interaction (FM-Sky) have already been intensively investigated both experimentally and theoretically. In contrast, skyrmions in materials with AFM exchange (AFM-Sky), which are predicted to exhibit an even stronger spin torque without any skyrmion Hall effect, have so far been only proposed within the framework of model calculations. In cooperation with experts in DFT from the University of Kiel (Heinze) we will investigate skyrmion formation in AFM thin films. In addition to films with lateral AFM exchange, so-called “G-type” antiferromagnets, we will also perform experiments on layered antiferromagnets where individual atomic layers couple FM but the inter-layer coupling is AFM. Once discovered we will investigate how skyrmions can be generated, manipulated, or annihilated by global external or local STM-induced fields. In cooperation with the FZ Jülich (Lounis) we will also study how the properties of single skyrmions or the interactions between them respond to intentionally deposited adatoms or molecules. WP(ii) — Magnetic skyrmion systems investigated so far always consisted of two-dimensional films with rather isotropic exchange mechanisms. Recently, we discovered strongly anisotropic chiral magnetic structures in one-dimensional TMOs epitaxially grown on heavy fcc(001) surfaces. In cooperation with FZ Jülich (Lezaic/Blügel) we will investigate the indirect magnetic exchange coupling responsible for these spiral spin structures. Towards this purpose, we will study how the magnetic structure responds to external magnetic fields or an increased temperature. Furthermore, we will image the propagation of domain walls (solitons) in these spin spirals. WP(iii) — Charge currents exert an extraordinary large spin torque on magnetic skyrmions. We will investigate charge and spin transport through single skyrmions by means of STM-induced remote molecule isomerization studies and compare the results to conventional domains and domain walls. This novel technique allows to interrogate the effects of single defects with unprecedented resolution.

在该项目中，我们将利用自旋扫描隧道显微镜（SP-STM）的原子分辨率功能，以（i）在防铁磁性（AFM）膜中准备和直接对Skyrmions进行，（ii）研究高度各向异性的触及鼠质旋转结构和磁性强度的强度跨度（II型），并在高度各向异性的跨性别跨性别（TM）中（TM）（TM）（TM）（TM）磁性域壁和天空与电流相互作用。为了实现这些目标，我们将以原子分辨率对真实空间自旋结构进行成像，并研究外部刺激的影响，例如全球外部磁场或STM尖端应用的局部电场脉冲。此外，我们将研究单分子或原子缺陷对磁空的形成，大小，形状和迁移率的影响。 WP（i） - 具有铁磁交换相互作用（FM-SKY）的天空已经对我们进行了深入的研究。相比之下，迄今为止，仅在模型计算的框架内提出了迄今为止提出的具有AFM Exchange（AFM-SKY）的材料（AFM-SKY）的材料（AFM-SKY）的天空。与基尔大学（Heinze）DFT的专家合作，我们将研究AFM薄膜中的Skyrmion组。除了具有侧向AFM交换的膜，所谓的“ G型”抗铁磁铁外，我们还将在分层的抗铁磁铁上进行实验，其中单个原子层夫妇FM FM，但层间耦合是AFM。一旦发现，我们将研究如何通过全球外部或局部STM诱导的田地来生成，操纵或an灭天空。在与FZJülich（Lounis）的合作中，我们还将研究单个天空的特性或它们之间的相互作用如何响应有意沉积的适配器或分子。 WP（ii） - 到目前为止所研究的磁性天空系统总是由具有相当各向同性交换机制的二维膜组成。最近，我们发现在重型FCC（001）表面上生长的一维TMO中强烈各向异性手性磁结构。与FZJülich（Lezaic/Blügel）合作，我们将研究负责这些螺旋自旋结构的间接磁交换耦合。为此，我们将研究磁性结构如何响应外部磁场或温度升高。此外，我们将在这些旋转螺旋中映像域壁（孤子）的传播。 WP（III） - 电荷电流在磁性天空上发挥出非凡的大型自旋扭矩。我们将通过STM诱导的远程分子异构化研究来调查通过单个天空的电荷和旋转传输，并将结果与​​常规域和域壁进行比较。这种新颖的技术允许以前所未有的分辨率询问单个缺陷的影响。