Collaborative research: The effects of Dzyaloshinskii Moriya interactions on magnetization dynamics in layered thin films

非技术摘要：本项目侧重于研究铁磁性材料和非磁性材料之间可能产生的相互作用。这种相互作用是形成磁性结构的关键，这种磁性结构有可能成为存储和传输信息的新手段，它也导致了磁性材料性质的不寻常变化，这对未来的设备很重要。布林莫尔学院和科罗拉多州立大学的研究小组正在采取合作的方法来研究磁相互作用和磁化动力学，以期对相互作用效应的潜在物理学有新的见解。对年轻一代的教育是这一项目的重要组成部分。私人投资机构努力让本科生和研究生都参与和培训学生，特别是妇女和来自代表人数不足的少数群体的学生。参与这个项目的学生还有机会与阿贡国家实验室的科学家合作，获得成像经验。私人投资机构将该项目的研究范例纳入这两个机构的教学和外展活动。技术摘要：导致各向异性交换效应的Dzyaloshinskii-Moriya相互作用(DMI)正迅速引起磁学和自旋电子学相关研究的关注。如果非磁性层表现出较高的自旋轨道耦合，则在块状手性晶体中以及在非磁性/磁性界面处可能会发生DMI，这是由于破坏了反转对称性和自旋-轨道耦合而引起的。DMI促进了稳定的手性磁自旋组态的形成，如Skyrmions，并显著改变了薄膜系统的动力学过程。结果表明，DMI可以影响薄膜的势垒和磁区壁运动，并导致扩展薄膜中表面自旋波的非互易性。DMI还应该显着改变图案化磁性纳米结构中的动力学，其中自旋动力学的波长由于几何限制效应而固有地短。在这项合作研究项目中，研究团队正在研究界面DMI对Skyrmion形成的影响，以及对延伸和图案化多层膜的自旋动力学的影响。多层膜不仅通过选择材料来调节DMI和表面各向异性，而且通过改变重复次数来调节静磁相互作用，从而提供了一种在室温下稳定亚微米级天空微子的方法。这一项目的结果带来了关于界面DMI的新信息，以及DMI对受限几何中Skyrmion形成和自旋动力学的影响。

Non-Technical Abstract:This project focuses on the study of the interactions that can arise at the boundary between ferromagnetic and non-magnetic materials. This interaction is key to the formation of magnetic structures that have potential as a new means to store and transmit information, and it also leads to unusual modifications of the properties of magnetic materials, important for future devices. The research teams at Bryn Mawr College and Colorado State University are taking a collaborative approach to study magnetic interactions and magnetization dynamics in order to gain new insight into the underlying physics of the interaction effects. Education for the young generation is an important component of this project. The PIs strive to involve and train students at both the undergraduate and graduate levels, especially women and students from underrepresented minority groups. The students working on this project also have the opportunity to collaborate with scientists at Argonne National Laboratory and gain hands on imaging experience. The PIs incorporate research examples from this project into teaching and outreach activities at both institutions. Technical Abstract:Dzyaloshinskii-Moriya interactions (DMI) that lead to anisotropic exchange effects are rapidly gaining attention in magnetism and spintronics-related research. DMI, which arise from broken inversion symmetry and spin-orbit coupling, can occur in bulk chiral crystals and at non-magnetic/magnetic interfaces if the non-magnetic layer exhibits high spin orbit coupling. DMI promote the formation of stable chiral magnetic spin configurations such as skyrmions, and significantly modify dynamic processes in thin film systems. It has been shown that DMI can influence skyrmion and domain wall motion and that DMI lead to a nonreciprocity for surface spin waves in extended thin films. DMI should also significantly modify the dynamics in patterned magnetic nanostructures where the wavelengths of the spin dynamics are inherently short due to geometric confinement effects. In this collaborative research project, the research teams are investigating the effects of interfacial DMI on skyrmion formation and on spin dynamics in both extended and patterned multilayered films. Multilayers provide a means to stabilize submicron-sized skyrmions at room temperature by tuning not only DMI and surface anisotropies through the choice of the materials, but also the magnetostatic interactions through varying the number of repeats. The results of this project lead to new information on interfacial DMI and the effects of DMI on skyrmion formation and spin dynamics in confined geometries.