基于磁skyrmion的自旋霍尔纳米振荡器研究

自旋霍尔纳米振荡器是基于自旋霍尔效应的新型微波发生器。其具有结构简单，不受铁磁体中电迁移和欧姆热影响，以及多样的探测方法等优点，引起了广泛的关注。然而，自旋霍尔纳米振荡器磁性层中较小的磁矩振荡幅度导致其输出功率最高才纳瓦量级，因此低的输出功率是当前限制其应用的最大挑战。本项目提出将磁skyrmion的旋转振荡模式应用于自旋霍尔纳米振荡器中，磁skyrmion作为一种具有拓扑保护性质的磁结构，有着稳定性高、临界驱动电流密度低等优点。更重要的是：在自旋霍尔效应的作用下，磁skyrmion可以实现局域区域磁矩的反转，即磁矩的振荡幅度有着最大的变化，有希望解决自旋霍尔纳米振荡器输出功率低的问题。本项目拟通过微磁学模拟去研究如何使得磁skyrmion在自旋霍尔效应的驱动下做周期性振荡运动，在提高功率的同时也优化频率和线宽等性能参数。因此，本项目对自旋霍尔纳米振荡器的应用有着重要意义。

Spin Hall nano-oscillator (SHNO) is a new type of microwave generators based on the spin Hall effect (SHE). It has the advantages of simple structure, unaffected by electromigration or Ohmic heating in the ferromagnets, and various detection methods, which has attracted large interest. However, the small amplitude of the magnetic moment oscillation in the magnetic layer of the SHNOs leads to the highest output power of only in the order of nanowatt level, the low output power is therefore the biggest challenge currently limiting its application. This project proposes to apply the oscillation mode of the magnetic skyrmion to the SHNOs. Magnetic skyrmion is magnetic structures with topological protection properties, which has the advantages of high stability and low critical drive current density. More importantly, the oscillation of the magnetic skyrmion can realize the reversal of the magnetic moment in the local area under the action of the SHE, i.e., the oscillation amplitude of the magnetic moments have the largest change, which is promising to solve the problem of low output power of the SHNOs. This project intends to investigate SHE-induced periodic oscillation of the magnetic skyrmion by using micromagnetic simulation, and optimize performance parameters such as frequency and linewidth while increasing power. Therefore, this project is of great significance to the application of the SHNOs.