诱导型手性微纳磁体中自旋波通道操纵与特性调控的模拟研究

Novel physical effects are required, in the post-Moore era, to meet the exploding demands of multiple applications by extending CMOS technology. Amongst the various existing alternative routes, magnonic technology has shown a huge potential for information processing. One of the primary tasks of magnonics is to find magnonic waveguides with superb performance. Compared with conventional magnonic waveguides, the optic-fiber-like magnonic waveguide based on strip-domain walls exhibits a lot of advantages and thus is more suitable for building magnonic devices. A set of manipulation methods and procedures for such waveguides must be established before any practical magnonic nanodevices can be made. With this project, we aim to study systematically, via micromagnetic simulations, the dynamics of strip-domain walls and spin waves under the action of spin-orbit torque, spin-transfer torque, and/or magnetic fields, and to lay the foundation for the design and optimization of new magnonic devices by revealing the impact of each individual factors of the hierarchy, materials parameters, defects, current-related parameters, temperature, etc. on the dynamics, by clarifying the physical mechanisms underlying the observed dynamic behaviors, and by developing useful techniques for writing of strip-domain walls as well as for manipulation of spin-wave characteristics in such magnonic waveguides. Additionally, our research is expected to help deepen the understanding of the motion of topological magnetic objects in ultrathin magnetic multilayers and, further, help uncover the roles of spin-Hall torque, Rashba torque, and spin-transfer torque in the current-driven motion of magnetic domain walls.

后摩尔时代需要新物理来拓展CMOS技术以满足急剧膨胀的应用需求，在现存的多种可替代方案中，磁振子技术具有巨大应用潜力。寻找性能优异的磁振子波导模是磁振子学研究的核心任务之一。相对于传统磁振子波导，基于条形畴壁的光纤型磁振子波导呈现多种优势，因此更适用于磁振子器件;在构建实用化的微纳磁振子器件之前，还需要发展一系列自旋波操控方法和技术。本项目通过微磁模拟对微纳磁体中条形畴壁和自旋波在自旋轨道矩、自旋转移矩以及磁场作用下的动力学进行系统研究，通过揭示体系层次结构、材料参数、样品缺陷、电流相关参数、温度等因素对相关动力学行为的影响，阐明条形畴壁和自旋波的运动规律与机制，发展有效的波导通道写入方法和自旋波特性调控技术，为新型磁振子器件设计与性能优化提供理论依据。另外，本项目成果有望增进对拓扑磁结构运动机制的理解，进一步揭示自旋霍尔矩、Rashba矩以及自旋转移矩在电流驱动的磁畴壁运动过程中的效能。

后摩尔时代需要寻找新物理效应来拓展CMOS技术以满足急剧膨胀的应用需求，在现存的多种可替代方案中，磁振子技术具有巨大的应用潜力。寻找性能优异的磁振子波导是磁振子学研究的重要课题。相对于传统磁振子波导，基于条形畴壁的光纤型磁振子波导具有多种优势，因此更适用于构建磁振子器件；为了推动微纳磁振子器件的实用化，还需要发展一系列自旋波操控方法和技术。本项目通过微磁模拟研究了微纳磁体中条形畴壁和自旋波在自旋轨道矩、自旋转移矩以及磁场作用下的动力学，揭示出体系结构、材料参数、样品缺陷、电流相关参数等因素对相关动力学行为的影响，发展了有效的波导通道写入方法和自旋波特性调控技术。另外，本项目通过将条形畴壁用于约束斯格明子的运动，有效地抑制了斯格明子霍尔效应，提高了其运动速度，增大了阈值电流密度，从而加深了对拓扑磁结构运动机制的理解。考虑到条形畴壁可作为磁振子波导，本项目将这一概念拓展到非平面情形，表明磁性斯格明子管可作为非平面磁振子波导。本项目研究成果将为自旋电子器件设计提供新思路。