Frequencies of Radially Symmetric Excitations in Vortex State Disks
Frequencies of Radially Symmetric Excitations in Vortex State Disks
复制标题
涡旋态盘中径向对称激励的频率
DOI：
10.1109/tmag.2008.2010474
复制
发表时间：
2009
影响因子：
2.1
通讯作者：
B. Ivanov
中科院分区：
文献类型：
--
作者：
C. E. Zaspel;A. Galkin;B. Ivanov
具有涡旋基态的亚微米铁磁圆盘表现出有趣的和潜在的有用的动力学性质所产生的激发基态。特别地，垂直于涡旋平面施加的磁脉冲将激发径向对称模式。基于线性化的Landau-Lifschitz方程和静磁绿色函数的这些模式的频率的先前计算给出了与纵横比radic（L/R）的平方根成比例的本征频率，其中L是盘厚度，R是盘半径。然而，实验频率数据显示显著偏离平方根依赖性。通过利用这些模式的高度对称性，通过集体变量方法来完成频率的改进计算。在线性近似中，这种方法给出了与半径成比例的频率的主要贡献（（L/R）ln（R/L）），这更接近于观察到的纵横比依赖性。
Submicron ferromagnetic disks with a vortex ground state exhibit interesting and potentially useful dynamic properties arising from excitations on the ground state. In particular, a magnetic pulse applied perpendicular to the vortex plane will excite radially symmetric modes. Previous calculations of the frequencies of these modes based on the linearized Landau-Lifschitz equation and the magnetostatic Green's function give eigenfrequencies proportional to the square root of the aspect ratio radic(L/R), where L is the disk thickness and R is the disk radius. However, experimental frequency data show significant deviation from the square root dependence. An improved calculation of the frequency is done through a collective variable approach by exploiting the high symmetry of these modes. In the linear approximation, this approach gives the main contribution to the frequency proportional to radic((L/R)ln(R/L)), which is closer to the observed aspect ratio dependence.