Ultrafast Dynamics of choral spin structures in magnetic multilayer systems

本项目的目的是在实验室中使用X射线自由电子激光源和基于高次谐波产生的源，通过采用时间分辨X射线共振磁散射方法来研究超快手征动力学。我们建议利用红外和X射线激发不同的磁性系统显示手征磁序，并探测手征和共线磁序参数的时间演化。由于手征磁序及其超快动力学的特征时标至今尚未探索，我们需要确定两者，因为它们对潜在的物理机制有基本的了解，并允许我们测量操纵手性磁性的最终速度，例如，用于手征自旋纹理的超快写入。我们建议研究以下几个方面来理解多层系统中手征磁性的超快动力学：（i）Dzyaloshinskiii-Moriya相互作用在铁磁系统中的大小和符号的作用;（ii）手征拓扑对象（如skyrmions）的静态和动态特性。

The aim of this project is to study the ultrafast chiral dynamics by employing time-resolved X-ray resonant magnetic scattering methods using both X-ray free-electron laser sources and sources based on higher harmonic generation in the laboratory. We propose to employ IR and X-ray excitation of different magnetic systems display chiral magnetic order and to probe the temporal evolution of the chiral and collinear magnetic order parameters Since the characteristic timescale for the onset of the chiral magnetic order and its ultrafast dynamics are unexplored up to now, we need to ascertain both, as they hold fundamental insights into the underlying physical mechanisms and allow us to gauge the ultimate speed for the manipulation of chiral magnetism, e.g., for ultrafast writing of chiral spin textures. We propose to investigate the following aspects to understand ultrafast dynamics of chiral magnetism in multilayer systems: (i) the role of size and sign of the Dzyaloshinskii-Moriya interaction in ferromagnetic systems and (ii) static and dynamic properties of chiral topological objects such as skyrmions.