Magnetic skyrmions in chiral multilayers

手性多层膜中的磁性斯格明子

• 批准号: 2752169
• 金额: --
• 依托单位: University of Leeds
• 依托单位国家: 英国
• 项目类别: Studentship
• 财政年份: 2022
• 资助国家: 英国
• 起止时间: 2022 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=studentship-2752169
• 关键词: Magnetic; skyrmions; chiral; multilayers

In this project we will study magnetic skyrmions, nanoscale swirls of spins that possess a non-trivial topology. They appear in properly designed magnetic multilayers at room temperature and are candidates for next-generation data storage technology. It is now over a decade since the carbon footprint of the internet grew larger than that of commercial air travel, much of this energy is used to physically spin hard disks, write data to them, and write and refresh volatile memory. To drive skyrmions along a crystal using spin torque requires several orders of magnitude less current density then driving magnetic domains under ideal conditions, but this is not seen in practice in these systems so far. Magnetic skyrmions offer the prospect of vastly reducing the energy needed to write and store digital data if their properties can be controlled.The proposed focus of this project is the mobility of skyrmions at room temperature under the influence of enhanced spin-orbit torques provided by placing the skyrmion-bearing multilayer on top of another material with suitable properties. The student will grow the heterostructures, characterise them structurally and magnetically, and then pattern them into nanoscale devices in which the high current densities needed to generate spin-torques can be achieved with reasonable currents. Skyrmion nucleation and motion will then be studied by means of magnetic imaging.

在这个项目中，我们将研究磁旋，具有非平凡拓扑结构的纳米级自旋旋。它们在室温下出现在适当设计的磁性多层材料中，是下一代数据存储技术的候选材料。十多年前，互联网的碳足迹超过了商业航空旅行的碳足迹，其中大部分能源被用于物理旋转硬盘、向硬盘写入数据、写入和刷新易失性存储器。在理想条件下，利用自旋扭矩驱动晶体上的skyrmions所需的电流密度比驱动磁畴所需的电流密度小几个数量级，但到目前为止，在这些系统中还没有看到这一点。磁性skyrmions提供了一个前景，如果它们的特性可以被控制，将大大减少写入和存储数字数据所需的能量。本项目提出的重点是在室温下，通过将承载skyrmion的多层材料放置在另一种具有合适性能的材料上，提高自旋轨道扭矩的影响下，skyrmions的迁移率。学生将培养异质结构，对其结构和磁性进行表征，然后将其制成纳米级器件，在这种器件中，产生自旋扭矩所需的高电流密度可以在合理的电流下实现。然后用磁成像的方法研究Skyrmion的成核和运动。