动态磁斯格明子的研究

One of the most heavily researched topics in solid state physics and nanomagnetism in recent years is a particle-like topological soliton, the magnetic skyrmion, which holds great promise for applications such as ultradense information storage and spin logic devices. In contrast to the skyrmion that has a spin texture with a quantized topological number, the non-topological magnetic droplet soliton has a skyrmion number equal to zero. This non-topological magnetic droplet was only experimentally observed in 2013, despite having been theoretically predicted 38 years ago. Interest in both skyrmions and droplet solitons has continued to rapidly increase as evidenced by the number of publications in high impact journals in 2014-2015...In this proposal, we aim to numerically, theoretically, and experimentally investigate the dynamical magnetic skyrmion (DMS), an entirely unexpected, novel, and intriguing dynamic magnetic object that combines the properties of droplets and skyrmions. The objectives of this project include (1) developing both an analytical theory and micromagnetic simulations for studying the dynamics of droplet solitons and DMS in constricted geometries, (2) developing new mechanisms for creating and manipulating skyrmions and DMS in magnetic nanostructures, and (3) experimentally fabrication of spin-torque nano oscillators. These novel magnetic nano-objects have tremendous potential for both fundamental science and applied research. Through our efforts and activities, we will propel China as the leading international player in fundamental spintronics research, leading the way in next-generation information storage and processing technologies that are low cost, have ultra-low energy efficiency and enhanced performance.

磁斯格明子是一种类粒子的拓扑纳米磁结构，在信息存储和处理方面具有广阔的应用前景，成为最近几年固体物理和纳米磁学领域的一个研究热点。在磁斯格明子的研究迅速发展的同时，一种新型的非拓扑的动态自旋有序结构磁孤子也在实验上于2013年被发现。磁斯格明子和磁孤子成为自旋电子学领域的研究热点。.我们计划从数值解析、理论以及实验的角度研究动态磁斯格明子 — 一种全新的兼具磁斯格明子和磁孤子特性的纳米磁结构。本项目的研究目标包括：（1）发展一套解析理论和数值模拟方法研究动态磁斯格明子在纳米铁磁体里的磁动力学特性；（2）提出新的机制在纳米线、纳米盘等体系里来产生和驱动动态磁斯格明子; (3) 实验上制备自旋力矩振荡器为实验上观测和实现这种新的磁结构奠定基础。这种全新的拓扑纳米磁结构对基础科学和应用研究都有极大的潜力。我们希望通过本项目可以使得中国在纳米电子学方面得以进一步的发展，从而在新一代信息技术的变革中抢占先机。

磁斯格明子是一种具有准粒子特性的拓扑纳米磁畴壁结构。 由于磁斯格明子具有较好的稳定性和新奇的物性, 并可被磁场、电场、电流、应力等方式调控, 有望成为高密度、低耗能、非易失性信息存储及逻辑运算的新兴信息载体。在此项目中，我们从数值解析、理论以及实验的角度研究动态磁斯格明子及其器件应用。项目取得的主要研究结果包括：（1）发展一套微磁学模拟程序研究磁斯格明子的动力学特性；（2）把磁斯格明子材料体系从传统的铁磁材料扩展到磁阻挫材料、反铁磁材料以及亚铁磁材料，极大的拓展了斯格明子体系的材料选择和应用前景；（3）建立了一套基于Thiele方程的解析理论和数值计算结果以及实验结果进行比较，指导进一步的实验工作；（4）提出新的机制在纳米盘等体系里来产生和驱动动态磁斯格明子，实现了磁斯格明子高频微波振荡器。项目累计发表文章32篇，其中包括两篇Nature Communications, 一篇Nano Letters，一篇National Science Review，获得专利一项，并受邀在国际磁学大会上作邀请报告。通过本项目，我们在斯格明子学国际学术领域起到了一定的引领作用，使得我国在新型磁斯格明子电子学器件上研发的地位上得到进一步提高。