Manipulation of skyrmions with tailored acoustic potentials

利用定制的声势操纵斯格明子

• 批准号: 2881683
• 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: 2023
• 资助国家: 英国
• 起止时间: 2023 至 无数据
• 项目状态: 未结题
• 来源: https://gtr.ukri.org/projects?ref=studentship-2881683
• 关键词: Manipulation; skyrmions; tailored; acoustic; potentials

Magnetic skyrmions are nanoscale, particle-like swirling spin textures with a non-zero topological charge that appear in some condensed matter systems such as magnetic multilayers. About a decade ago it was predicted that they could be transported along a magnetic wire using small amounts of electrical current, and this has led to a variety of proposals for their use in magnetic memory and non-von Neumann computing architectures. However, in practice skyrmion motion is hindered by grain boundaries and other imperfections in the magnetic material, meaning that far more current is needed than predicted, leading to energy wastage mainly in the form of Joule heating. Rather than try to refine the magnetic material any further, what we will do in this project is avoid using currents altogether, and instead use surface acoustic waves (SAWs) to manipulate skyrmions. The aim of the PhD project is to further investigate the manipulation of skyrmions by SAWs, mainly by experiment, but complemented by micromagnetic simulations. Synthetic antiferromagnetic (SAF) multilayers that we currently study contain skyrmions that are even smaller than those in ferromagnets, and hold promise for low-power manipulation, and it is SAF materials that will mainly be investigated in this project. The main challenges of the project are to fabricate GHz frequency SAW transducers for the manipulation of these nanoscale skyrmions and to detect the skyrmion response. The Royce Deposition System and magnetic characterisation tools within the Condensed Matter Group will be used to deposit and study the SAF multilayers. SAW transducers will be fabricated in the university's Wolfson cleanroom. Structural characterisation and microscopy will be performed using Bragg Centre facilities. Synchrotron techniques will complement the magnetic imaging available in Leeds.

磁性斯格明子是纳米级、粒子状的旋转自旋纹理，具有非零拓扑电荷，出现在一些凝聚态物质系统（例如磁性多层）中。大约十年前，人们预测它们可以使用少量电流沿着磁线传输，这导致了将它们用于磁存储器和非冯诺依曼计算架构的各种建议。然而，在实践中，斯格明子运动受到晶界和磁性材料中其他缺陷的阻碍，这意味着需要比预期更多的电流，导致能量浪费主要以焦耳热的形式。我们在这个项目中要做的是完全避免使用电流，而是使用表面声波（SAW）来操纵斯格明子，而不是尝试进一步改进磁性材料。该博士项目的目的是进一步研究声表面波对斯格明子的操纵，主要通过实验，但辅以微磁模拟。我们目前研究的合成反铁磁（SAF）多层材料含有比铁磁体中的斯格明子还要小的斯格明子，有望实现低功率操控，本项目将主要研究的是SAF材料。该项目的主要挑战是制造 GHz 频率 SAW 换能器来操纵这些纳米级斯格明子并检测斯格明子响应。凝聚态组内的罗伊斯沉积系统和磁性表征工具将用于沉积和研究 SAF 多层膜。 SAW 传感器将在该大学的 Wolfson 洁净室中制造。结构表征和显微镜检查将使用布拉格中心的设施进行。同步加速器技术将补充利兹现有的磁成像技术。