随着人类社会逐渐从信息化向智能化转变，爆炸式增长的信息量对数据存储器件提出了更高的要求。以磁随机存储器和磁斯格明子赛道存储器为代表的磁性存储器因其兼具内存的高速度和闪存的非易失性，有望成为下一代存储器的有力竞争者。传统铁磁材料由于存在杂散场，存在静磁相互干扰和对外磁场敏感等缺点，反铁磁材料由于没有净磁矩可以克服以上问题，但是对其磁矩的操控和探测十分困难。本文围绕着兼具铁磁材料易操控与易探测以及反铁磁材料无杂散场、磁化动力学快优势的人工磁性多层膜材料，开展对其磁矩的高效操控、磁性斯格明子的可控产生与操纵以及层间非共线相互作用的探测等一系列研究，旨在构建基于人工磁性多层膜的高性能磁随机存储器和磁斯格明子赛道存储器，推动磁存储技术的发展。理论上揭示了铁磁与重金属之间界面有序度对界面Dzyaloshinskii-Moriya相互作用（DMI）的影响。通过结构设计与界面调控，在重金属Pt楔形结构上的人工反铁磁[Co/Pd]/Ru/[Co/Pd]中实现了无外加辅助磁场自旋轨道力矩诱导的磁矩完全翻转。在[Pd/Co]/Ru/[Co/Pd]人工反铁磁中，观察到磁场方向依赖的磁化翻转行为和类似拓扑霍尔效应特征，阐明了人工反铁磁体系中能量竞争对磁矩翻转行为的影响，揭示了多层膜结构中界面合金化对反常霍尔效应系数的影响。为了可控产生和操纵人工反铁磁斯格明子，通过电流和磁场的协同作用，在具有合适垂直磁各向异性的人工反铁磁中产生了直径约为80纳米的孤立和高密度斯格明子。采用Pt/铁磁体/Ir/Pt/铁磁体/Ir结构，提高界面DMI，同时利用热效应可控产生人工反铁磁斯格明子，实现了人工反铁磁斯格明子的定向运动，打破了由斯格明子霍尔效应带来的运动轨迹偏移难题。利用声表面波延迟线结构产生的热效应和声表面波，实现了铁磁斯格明子的有序化排列，成功抑制了铁磁体系中的斯格明子霍尔效应，为高效操控磁性多层膜体系中的斯格明子提供了新的思路。结合实验和理论计算结果，在人工磁性多层膜中发现了层间DMI的各向异性和类似Ruderman-Kittel-Kasuya-Yosida相互作用的阻尼振荡特征。阐明了面内反演对称性破缺是产生层间DMI的重要基础，揭示了耦合层厚度相关的层间DMI阻尼振荡现象是磁性金属多层膜结构中的本征行为，证明了层间DMI是一类长程相互作用，为进一步理解层间非共线相互作用奠定了基础。
With the transformation of human society from information to intelligence, massive information has put forward higher requirements for data storage. Magnetic memory, such as Magnetic Random-Access Memory (MRAM) and Magnetic Skyrmion-Racetrack Memory (SRM), is expected to become the strong competitor of next generation memory for its advantages which combine the high speed of DRAM memory and non-volatile of flash memory. Due to the existence of stray field, traditional ferromagnetic materials face the drawbacks of magnetostatic interference and sensitivity to external magnetic field. Although antiferromagnetic materials have no net magnetic moment which can overcome these problems, manipulation and detection of antiferromagnetic moments are difficult. In this paper, a series of researches on the efficient manipulation of magnetic moments, the controllable generation and manipulation of magnetic skyrmions, and the detection of interlayer non-collinear interactions in synthetic magnetic multilayers are carried out based on synthetic antiferromagnets which combine the advantages of easy manipulation and detection like ferromagnetic materials and no stray field and fast magnetization dynamics like antiferromagnetic materials, aiming at constructing high-performance MRAM and SRM and promoting the development of magnetic storage technology.The influence of the degree of interfacial order between ferromagnetism and heavy metals on interfacial Dzyaloshinskii-Moriya interaction (DMI) was theoretically revealed. By means of structural design and interfacial engineering, complete switching of magnetic moment induced by spin orbit torque without applied auxiliary magnetic field was achieved in synthetic antiferromagnetic [Co/Pd]/Ru/[Co/Pd] structure grown on a wedge-shaped Pt heavy metal. In [Pd/Co]/Ru/[Co/Pd] synthetic antiferromagnetic system, the magnetic field direction dependent magnetization switching behavior and topological Hall effect like features are observed. The influence of energy competition on magnetization switching behavior in synthetic antiferromagnetic system is clarified, and the influence of interfacial alloying on anamolous Hall effct coefficient in multilayer structure is revealed.In order to controllable create and manipulate synthetic antiferromagnetic skyrmions, synthetic antiferromagnet with suitable perpendicular magnetic anisotropy was designed in which isolated and high-density skyrmions with the diameter about 80 nm are generated through the synergistic excitation of current and magnetic field. Using Pt/ferromagnet/Ir/Pt/ferromagnet/Ir structure, the interfacial DMI is improved. Thus, by means of thermal effect, synthetic antiferromagnetic skyrmions were controllably generated and the directional motion of synthetic antiferromagnetic skyrmions was realized, solving the problem of trajectory deviation caused by skyrmion Hall effect. Through the thermal effects and surface acoustic waves generated via a delay line device, the ordered arrangement of ferromagnetic skyrmions is realized, and the skyrmion Hall effect is successfully suppressed, providing a new dimension for the efficient control of skyrmions in magnetic multilayer systems.The anisotropy of DMI and the damped oscillation characteristics similar to Ruderman-Kittel-Kasuya-Yosida interaction are found in the synthetic magnetic multilayers by combining the experimental and theoretical results. It is proved that the interlayer in-plane inversion symmetry breaking is necessary for the generation of interlayer DMI, the damped oscillation between interlayer DMI and exchange coupling layer thickness is an intrinsic behavior of magnetic metal multilayer structure and the interlayer DMI is a kind of long-range interaction. All these findings would lay a foundation for the further understanding of non-collinear interlayer interaction.
