Brearton R, Turnbull L A, Verezhak J A T, Balakrishnan G, Hatton P D, van der Laan G, Hesjedal T
Department of Physics, Clarendon Laboratory, University of Oxford, Oxford, UK.
Diamond Light Source, Harwell Science and Innovation Campus, Didcot, UK.
Nat Commun. 2021 May 11;12(1):2723. doi: 10.1038/s41467-021-22857-y.
Magnetic skyrmions are topologically non-trivial, swirling magnetization textures that form lattices in helimagnetic materials. These magnetic nanoparticles show promise as high efficiency next-generation information carriers, with dynamics that are governed by their topology. Among the many unusual properties of skyrmions is the tendency of their direction of motion to deviate from that of a driving force; the angle by which they diverge is a materials constant, known as the skyrmion Hall angle. In magnetic multilayer systems, where skyrmions often appear individually, not arranging themselves in a lattice, this deflection angle can be easily measured by tracing the real space motion of individual skyrmions. Here we describe a reciprocal space technique which can be used to determine the skyrmion Hall angle in the skyrmion lattice state, leveraging the properties of the skyrmion lattice under a shear drive. We demonstrate this procedure to yield a quantitative measurement of the skyrmion Hall angle in the room-temperature skyrmion system FeGe, shearing the skyrmion lattice with the magnetic field gradient generated by a single turn Oersted wire.
磁斯格明子是拓扑非平凡的、呈漩涡状的磁化纹理，在螺旋磁体材料中形成晶格。这些磁性纳米粒子有望成为高效的下一代信息载体，其动力学受拓扑结构支配。斯格明子的许多独特性质之一是其运动方向倾向于偏离驱动力方向；它们偏离的角度是一个材料常数，称为斯格明子霍尔角。在磁性多层系统中，斯格明子通常单独出现，而不是排列成晶格，通过追踪单个斯格明子的实空间运动，可以很容易地测量这个偏转角。在此，我们描述了一种倒易空间技术，利用剪切驱动下斯格明子晶格的特性，该技术可用于确定斯格明子晶格状态下的斯格明子霍尔角。我们展示了该过程能够对室温下的斯格明子系统FeGe中的斯格明子霍尔角进行定量测量，利用单匝奥斯特线产生的磁场梯度对斯格明子晶格进行剪切操作。
