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，我们将研究磁性斯格明子，即具有非平凡拓扑结构的纳米级自旋漩涡。它们在室温下出现在经过适当设计的磁性多层中，是下一代数据存储技术的候选者。十多年来，互联网的碳足迹已经超过商业航空旅行的碳足迹，其中大部分能源用于物理旋转硬盘、向硬盘写入数据以及写入和刷新易失性内存。使用自旋扭矩沿晶体驱动斯格明子所需的电流密度比理想条件下驱动磁域的电流密度低几个数量级，但迄今为止在这些系统的实践中还没有看到这种情况。如果磁性斯格明子的特性可以控制，那么其有望大大减少写入和存储数字数据所需的能量。该项目的重点是在通过放置提供增强的自旋轨道扭矩的影响下，斯格明子在室温下的迁移性带有斯格明子的多层结构位于另一种具有合适特性的材料之上。学生将生长异质结构，表征它们的结构和磁性，然后将它们图案化为纳米级器件，在这些器件中可以通过合理的电流实现产生自旋扭矩所需的高电流密度。然后将通过磁成像研究斯格明子成核和运动。