Bhukta Mona, Dohi Takaaki, Bharadwaj Venkata Krishna, Zarzuela Ricardo, Syskaki Maria-Andromachi, Foerster Michael, Niño Miguel Angel, Sinova Jairo, Frömter Robert, Kläui Mathias
Institute of Physics, Johannes Gutenberg-University Mainz, 55099, Mainz, Germany.
Laboratory for Nanoelectronics and Spintronics, Research Institute of Electrical Communication, Tohoku University, 2-1-1 Katahira, Aoba, Sendai, 980-8577, Japan.
Nat Commun. 2024 Feb 26;15(1):1641. doi: 10.1038/s41467-024-45375-z.
The ever-growing demand for device miniaturization and energy efficiency in data storage and computing technology has prompted a shift towards antiferromagnetic topological spin textures as information carriers. This shift is primarily owing to their negligible stray fields, leading to higher possible device density and potentially ultrafast dynamics. We realize in this work such chiral in-plane topological antiferromagnetic spin textures namely merons, antimerons, and bimerons in synthetic antiferromagnets by concurrently engineering the effective perpendicular magnetic anisotropy, the interlayer exchange coupling, and the magnetic compensation ratio. We demonstrate multimodal vector imaging of the three-dimensional Néel order parameter, revealing the topology of those spin textures and a globally well-defined chirality, which is a crucial requirement for controlled current-induced dynamics. Our analysis reveals that the interplay between interlayer exchange and interlayer magnetic dipolar interactions plays a key role to significantly reduce the critical strength of the Dzyaloshinskii-Moriya interaction required to stabilize topological spin textures, such as antiferromagnetic merons, in synthetic antiferromagnets, making them a promising platform for next-generation spintronics applications.
在数据存储和计算技术中，对设备小型化和能源效率的需求不断增长，促使人们转向反铁磁拓扑自旋纹理作为信息载体。这种转变主要是由于它们的杂散场可以忽略不计，从而导致更高的可能设备密度和潜在的超快动力学。在这项工作中，我们通过同时设计有效垂直磁各向异性、层间交换耦合和磁补偿比，在合成反铁磁体中实现了这种面内手性拓扑反铁磁自旋纹理，即磁子、反磁子和双磁子。我们展示了三维奈尔序参量的多模态矢量成像，揭示了这些自旋纹理的拓扑结构和全局明确的手性，这是控制电流诱导动力学的关键要求。我们的分析表明，层间交换和层间磁偶极相互作用之间的相互作用起着关键作用，可显著降低在合成反铁磁体中稳定拓扑自旋纹理（如反铁磁磁子）所需的Dzyaloshinskii-Moriya相互作用的临界强度，使其成为下一代自旋电子学应用的有前途的平台。
