正弦微波磁场驱动亚铁磁畴壁动力学  

Dynamics of ferrimagnetic domain walls driven by sinusoidal microwave magnetic field

作　　者：赵晨蕊 魏云昕 刘婷婷 秦明辉 Zhao Chen-Rui;Wei Yun-Xin;Liu Ting-Ting;Qin Ming-Hui(Guangdong Provincial Key Laboratory of Quantum Engineering and Quantum Materials,South China Institute of Advanced Optoelectronics,South China Normal University,Guangzhou 510006,China)

机构地区：[1]华南师范大学华南先进光电子研究院,广东省量子调控工程与材料重点实验室,广州510006

出　　处：《物理学报》2023年第20期77-83,共7页Acta Physica Sinica

基　　金：国家自然科学基金(批准号:U22A20117,52371243,51971096);广东省自然科学基金(批准号:2022A1515011727);广州市科技计划项目(批准号:202201000008)资助的课题.

摘　　要：亚铁磁畴壁在角动量补偿点附近具有非零净磁化强度,同时具有超快动力学性质,有望应用于未来的自旋电子学存储和逻辑器件中.探寻低能耗和高效驱动畴壁的手段和机制可以为实验设计和器件开发提供重要参考.本文使用理论分析和微磁学模拟研究了亚铁磁畴壁在正弦微波磁场驱动下的动力学行为,表明了微波磁场在一定的频率范围内可有效驱动畴壁运动,使得人们可通过调制不同频率的微波磁场来调控畴壁动力学.本文详细分析和解释了正弦微波磁场驱动亚铁磁畴壁的物理机理,探讨了双轴各向异性等参数对畴壁运动速度的影响,表明了磁各向异性和外加微波磁场频率等参量对不同净自旋角动量亚铁磁畴壁的调控行为.Ferrimagnetic domain walls have received more and more attention because of their interesting physics and potential applications in future spintronic devices,particularly attributing their non-zero net magnetization and ultrafast dynamics.Exploring effective methods of driving domain walls with low energy consumption and high efficiency can provide important information for experimental design and device development.In this work,we study theoretically and numerically the dynamics of ferrimagnetic domain wall driven by the sinusoidal microwave magnetic field using the collective coordinate theory and Landau-Lifshitz-Gilbert simulations of atomistic spin model.It is revealed that the microwave field drives the propagation of the domain wall when the frequency falls into an appropriate range,which allows one to modulate the domain wall dynamics through tuning field frequency.Specifically,below the critical frequency,the domain wall velocity is proportional to the field frequency and the net angular momentum,while above the critical frequency,the domain wall velocity decreases rapidly to zero.The physical mechanisms of the results are discussed in detail,and the influences of the biaxial anisotropy and other parameters on the velocity of domain wall are studied.It is suggested that the wall dynamics can be effectively regulated by adjusting the basic magnetic structure and magnetic anisotropy,in addition to the external microwave field frequency.This work uncovers the interesting dynamics of ferrimagnetic domain wall driven by sinusoidal microwave magnetic field,which is helpful for designing domain wall-based spintronic device.

关 键 词：畴壁动力学 自旋电子学 正弦微波磁场 亚铁磁体 

分 类 号：O469[理学—凝聚态物理]