论文标题
用于建模方位角宏观景观中的径向自旋波的嬉皮曲线
Hippopede curves for modelling radial spin waves in an azimuthal graded magnonic landscape
论文作者
论文摘要
我们提出了一个数学模型,用于描述磁涡状n顶点在磁性涡流状态下从核心区域发出的径向传播的自旋波。表面自旋波(SSW)进入域的方位角各向异性繁殖,在域壁中限制自旋波(或冬季的镁质,WM)会增加镁质景观的复杂性。为了理解这些系统中的自旋波传播,我们首先使用一种基于几何曲线的方法,称为“嬉皮”,但是它没有对基础物理学的见解。分析模型依赖于SSW与磁化M和波数k之间任意角度的分散性关系的广义表达。发现方位角分散的派生代数表达与“河马”曲线的代数表达相当。来自模型的拟合曲线在任何给定的方位角,斑块顶点和激发频率的数量上产生了自旋波长,显示了与交换主导的表面自旋波的基本物理的联系。分析结果表明,与微磁模拟良好一致,并且可以轻松地外推到任何N-Corner贴片几何形状。
We propose a mathematical model for describing radially propagating spin waves emitted from the core region in a magnetic patch with n vertices in a magnetic vortex state. The azimuthal anisotropic propagation of surface spin waves (SSW) into the domain, and confined spin waves (or Winter's Magnons, WM) in domain walls increases the complexity of the magnonic landscape. In order to understand the spin wave propagation in these systems, we first use an approach based on geometrical curves called 'hippopedes', however it provides no insight into the underlying physics. Analytical models rely on generalized expressions from the dispersion relation of SSW with an arbitrary angle between magnetization M and wavenumber k. The derived algebraic expression for the azimuthal dispersion is found to be equivalent to that of the 'hippopede' curves. The fitting curves from the model yield a spin wave wavelength for any given azimuthal direction, number of patch vertices and excitation frequency, showing a connection with fundamental physics of exchange dominated surface spin waves. Analytical results show good agreement with micromagnetic simulations and can be easily extrapolated to any n-corner patch geometry.