磁场与偏置场对涡旋畴壁振荡模式的调控  

Effect of Magnetic Field and Bias Field on Regulation of Oscillation Mode of Vortex Domain Wall

作　　者：甘凌霄 卢志红[1] 张振华 肖杨 李昆鹏 冯金地 赵新 GAN Lingxiao;LU Zhihong;ZHANG Zhenhua;XIAO Yang;LI Kunpeng;FENG Jindi;ZHAO Xin(College of Materials Science and Metallurgy,Wuhan University of Science and Technology,Wuhan 430081,Hubei,China)

机构地区：[1]武汉科技大学材料与冶金学院,湖北武汉430081

出　　处：《武汉大学学报(理学版)》2024年第6期769-774,共6页Journal of Wuhan University:Natural Science Edition

基　　金：国家自然科学基金(51871170)。

摘　　要：纳米结构中的畴壁振荡行为在微波纳米振荡器中具有很好的应用前景。采用微磁学方法,对纳米带结构中涡旋畴壁在不同磁场驱动下涡旋畴壁振荡模式进行了研究,探究了同一磁场不同的偏置场下对涡旋畴壁振荡模式的影响。研究结果表明:在不同的外加磁场下,涡旋畴壁的旋性会由一个旋性稳定不变的涡旋转变为涡旋和反涡旋交替出现,再转变为旋性发生改变的稳定涡旋。随着外磁场磁强度的增大,涡旋的振荡频率先增加后减小再增加;在同一外加磁场下,偏置场可以调控涡旋的旋性,改变偏置场大小可以将一个涡旋畴壁在旋性稳定不变的模式、涡旋和反涡旋交替出现的模式以及旋性发生改变的模式之间来回切换。涡旋畴壁的振荡频率随偏置场的变化趋势与随外加磁场的变化趋势一致。本研究为基于畴壁的新型纳米振荡器的振荡模式多途径调控提供了新思路。The oscillation behavior of domain walls in nanostructures presents significant potential for applications in microwave nano-oscillators.Using the micromagnetic simulation,the oscillation mode of vortex domain walls in nanowires driven by different magnetic fields is studied,and the effect of varying bias fields on the oscillation mode of the vortex domain wall under the same magnetic field is also explored.Results reveal that,under distinct external magnetic fields,the chirality of the vortex domain wall progresses from a chirality-stable vortex state to an alternating vortex and anti-vortex state,eventually reaching a stable vortex state with altered chirality.The oscillation frequency of the vortex increases first,then decreases,and consequently increases with the increase of the external magnetic field.The results also show that the bias field can control the vortexs chirality under the same external magnetic field.Changing the magnitude of the bias field can switch a vortex domain wall back and forth between the mode in which the chirality is stable,the mode in which the vortex and anti-vortex appear alternately,and the mode in which the chirality changes.The trend in oscillation frequency variation with bias field mirrors that observed with an applied magnetic field.This study provides a new idea for the multi-channel regulation of oscillation modes of new nano-oscillators based on domain walls.

关 键 词：涡旋畴壁 旋性 振荡频率 微磁模拟 偏置场 

分 类 号：O44[理学—电磁学] O469[理学—物理]