纳米带中涡旋畴壁在磁场驱动下的振荡行为

摘要

Based on the micromagnetic simulation software (OOMMF),micromagnetic simulation was conducted to investigate the dynamics of vortex domain wall in permolloy nanowire induced by mag-netic field which were slightly above the Walker limit field.The effects of magnetic field strength,ge-ometry of nanowire and polarized spin current on the oscillation frequency were studied.The results show that,with the increase of magnetic field strength,the oscillation frequency of the vortex domain wall increases.With the increase of the width of nanowire,the oscillation frequency first increases, then decreases and increases again,finally reaches a stable plateau.Moreover,after applying the bal-anced current that is antiparallel to the magnetic field,the variations of oscillation frequency with the magnetic field strength and nanowire width are in accordance with the case driven only by magnetic field,but the overall magnitude of frequency reduces.Meanwhile,the changing tendencies of the bal-anced current with the magnetic field strength and nanowire width are basically opposite to that of the oscillation frequency,while the balanced current increases linearly with the increase of the damping coefficient.%利用微磁学模拟软件(OOMMF),对坡莫合金纳米带中涡旋畴壁在略高于 Walker极限的磁场驱动下的动力学行为进行模拟,分析外磁场强度、纳米带尺寸及自旋极化电流对畴壁振荡频率的影响.结果表明,纳米带中涡旋畴壁的振荡频率随外磁场强度的增大而增加,随着纳米带宽度的增加呈先增加后减小再增大最后基本保持不变的趋势;外加与磁场方向相反的平衡电流,虽然不改变畴壁振荡频率随外磁场强度和纳米带宽度的变化规律,但能起到减小畴壁振荡频率的作用,且平衡电流随外磁场强度和纳米带宽度的变化趋势与畴壁振荡频率基本相反,而其随着阻尼系数的增大而线性增加.