Skyrmion spectroscopy in ferro- and antiferromagnets

铁磁体和反铁磁体中的斯格明子光谱

• 批准号: 403512431
• 负责人: Professor Dr. Philipp Pirro, since 5/2019
• 金额: --
• 依托单位: Arbeitsgruppe Magnetismus
• 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 2021-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/403512431?language=en
• 关键词: Skyrmion; spectroscopy; ferro; antiferromagnets

Combining expertise in theory and in Brillouin light scattering spectroscopy, we will explore the magnetic eigenmodes of skyrmions in ferro- and antiferromagnetic thin films including their excitations due to external stimuli. The main objective is to obtain a general picture for understanding and controlling magnetic excitations within single skyrmions and within skyrmion lattices. Our main experimental tool will be Brillouin light scattering spectroscopy (BLS). Regarding spin excitations in thin films, BLS excels over other existing techniques, since its high sensitivity allows for the detection of thermally excited magnetic eigenmodes of various symmetries, even from individual microstructures. BLS has evolved into one of the leading techniques for the quantification of the strength of the Dzyaloshinskii-Moriya interaction in thin films, and we will offer this experimental tool to all members of the SPP for a (comparative) analysis of their layers. The main aim of this project is to address several key issues of skyrmion excitations using a combined approach of state-of-the-art theoretical concepts, simulations and BLS experiments. The first goal will be the analysis and understanding of the thermally populated spectra of skyrmion lattices and individual skyrmions at room temperature. Here, BLS provides a unique way to access skyrmion excitations with finite wave vector. The second key goal is a comprehensive picture of linear skyrmion excitations in the presence of external stimuli. As stimuli, we will consider radiofrequency magnetic fields and spin currents. From the excited spectra, we will obtain valuable insights into the underlying processes which govern the skyrmion dynamics. As the third key issue, we will address the nonlinear skyrmion excitations arising from strong external drivings and their implications for skyrmion-based technologies like skyrmion racetrack memories or skyrmion nano-oscillators for radiofrequency applications. In our room temperature experiments, we will focus on layer systems incorporating ferromagnetic thin films which can be used in state-of-the-art spintronic devices where skyrmion eigenmodes typically feature GHz frequencies. To extend the field of skyrmionics to higher skyrmion velocities and to overcome the THz gap, each of the aforementioned goals also covers theoretical predictions for the corresponding phenomena in antiferromagnets, where dynamics are substantially different. This will include theories for antiferromagnetic skyrmion excitations and dynamics under controlled magnon fluxes. These theories in combination with our experimental results on ferromagnetic skyrmion dynamics will outline the path how skyrmion spectroscopy can be extended to the THz range inherent to antiferromagnetic dynamics which sets the goal for the next cycle. This will stimulate novel experiments on the creation and manipulation of antiferromagnetic skyrmions and their dynamics.

结合理论和布里频光散射光谱的专业知识，我们将探索铁磁和反铁磁薄膜中skyrmions的磁本征模式，包括它们在外部刺激下的激发。主要目标是获得理解和控制单个粒子和粒子格内磁激励的总体情况。我们的主要实验工具将是布里渊光散射光谱（BLS）。关于薄膜中的自旋激发，BLS优于其他现有技术，因为它的高灵敏度允许检测各种对称的热激发磁本征模式，甚至来自单个微结构。BLS已经发展成为薄膜中Dzyaloshinskii-Moriya相互作用强度量化的主要技术之一，我们将为SPP的所有成员提供这种实验工具，以对其层进行（比较）分析。该项目的主要目的是利用最先进的理论概念、模拟和BLS实验相结合的方法来解决skyrmion激励的几个关键问题。第一个目标将是分析和理解在室温下天空粒子晶格和单个天空粒子的热填充光谱。在这里，BLS提供了一种独特的方法来获取有限波矢量的skyrmion激励。第二个关键目标是在外部刺激存在的情况下，对线性skyrmion刺激的全面描述。作为刺激，我们将考虑射频磁场和自旋电流。从激发光谱，我们将获得有价值的见解，支配天空粒子动力学的基本过程。作为第三个关键问题，我们将解决由强外部驱动引起的非线性skyrmion激励及其对skyrmion技术的影响，如skyrmion赛道存储器或用于射频应用的skyrmion纳米振荡器。在我们的室温实验中，我们将把重点放在包含铁磁薄膜的层系统上，这种薄膜可以用于最先进的自旋电子器件，其中skyrmion本征模式通常具有GHz频率。为了将天元学领域扩展到更高的天元速度并克服太赫兹间隙，上述每个目标还涵盖了反铁磁体中相应现象的理论预测，其中动力学本质上不同。这将包括反铁磁斯基米子激发和控制磁振子通量下的动力学理论。这些理论结合我们在铁磁斯基米子动力学上的实验结果将勾勒出斯基米子光谱如何扩展到反铁磁动力学固有的太赫兹范围的路径，这为下一个周期设定了目标。这将激发关于反铁磁粒子及其动力学的创造和操作的新实验。