基于斯格明子的自旋转移矩纳米振荡器的微磁学模拟

Micromagnetic Simulation of Spin Transfer Torque Nano-Oscillator Based on Skyrmions

最近,人们发现了一种性能优良的新型磁性结构——斯格明子,为了解决传统微波发生器件能耗高、频谱窄等一系列问题,人们提出设计一种基于磁性斯格明子的自旋纳米振荡器。该器件的研发还处于理论设计阶段,因此有必要对斯格明子在器件中的产生及振荡机制进行研究。本文采用微磁学模拟方法,探究了极化电流密度以及DMI(Dzyaloshinkii-Moriya interaction)对斯格明子成核的影响规律。着重模拟了单个斯格明子在纳米圆盘中的振荡行为,并总结了电流密度以及DMI对斯格明子进动频率以及进动半径的影响。最后,探索了斯格明子个数对振荡器输出频率的影响,以期对该器件的研发提供理论预测和指导。

Recently,researchers have discovered an excellent novel magnetic structure called skyrmions.Based on skyrmions,Spin-torque Nano-oscillator is proposed to solve a series of problems such as high energy consumption and narrow frequency spectrum of traditional microwave generating devices.The research and development of the device are still in the theoretical design stage,so it is necessary to study the generation and oscillation mechanism of skyrmions in the device.In this paper,micro-magnetism simulation methods are used to explore the influence of polarization current density and DMI(DzyaloshinkiiMoriya interaction)on skyrmion nucleation.We focused on simulated the oscillation behavior of a single skyrmion in the nanodisk,and the effects of current density and DMI on skyrmion precession frequency and precession radius are summarized.Finally,the influence of the number of skyrmions on the output frequency of the oscillator is explored,in order to provide theoretical prediction and guidance for the development of the device.