Magnonic crystals — prospective structures for shaping spin waves in nanoscale
Magnonic crystals — prospective structures for shaping spin waves in nanoscale
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磁力晶体——塑造纳米级自旋波的前景结构
DOI：
10.1063/1.4932348
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发表时间：
2015
影响因子：
0.8
通讯作者：
Maciej Krawczyk
中科院分区：
文献类型：
--
作者：
J. Rychły;P. Gruszecki;M. Mruczkiewicz;J. Kłos;S. Mamica;Maciej Krawczyk
本文从理论上研究了一维、二维和三维周期性磁振子晶体中自旋波的能带结构。我们用平面波法、频域有限元法和时域微磁模拟方法求解Landau-Lifshitz方程，得到自旋波的动力学和本征模谱。在线性近似下计算了自旋波谱。在本文中，我们显示这些方法在计算各种类型的自旋波的有用性。本文研究了一维磁振子晶体中Damon-Eshbach自旋波的表面特性及其表面局域化随第一布里渊区带数和波数的变化。自旋波激发的表面性质通过用导体覆盖磁振子晶体的板被进一步利用。二维磁振子晶体中的能带结构是复杂的，由于额外的空间不均匀性引入的退磁场。这改变了自旋波色散，使得磁振子晶体的能带结构强烈依赖于夹杂物的形状和晶格类型。对于晶格常数小的磁振子晶体，内部磁场的不均匀性变得不重要，其中交换相互作用占主导地位。对于具有小晶格常数的三维磁振子晶体，我们发现了宽的磁振子带隙，并指出可以探索不同材料在磁振子晶体中的空间分布，以实现自旋波的定制有效阻尼。
We have investigated theoretically band structure of spin waves in magnonic crystals with periodicity in one- (1D), two- (2D) and three-dimensions (3D). We have solved Landau–Lifshitz equation with the use of plane wave method, finite element method in frequency domain and micromagnetic simulations in time domain to find the dynamics of spin waves and spectrum of their eigenmodes. The spin wave spectra were calculated in linear approximation. In this paper we show usefulness of these methods in calculations of various types of spin waves. We demonstrate the surface character of the Damon–Eshbach spin wave in 1D magnonic crystals and change of its surface localization with the band number and wavenumber in the first Brillouin zone. The surface property of the spin wave excitation is further exploited by covering plate of the magnonic crystal with conductor. The band structure in 2D magnonic crystals is complex due to additional spatial inhomogeneity introduced by the demagnetizing field. This modifies spin wave dispersion, makes the band structure of magnonic crystals strongly dependent on shape of the inclusions and type of the lattice. The inhomogeneity of the internal magnetic field becomes unimportant for magnonic crystals with small lattice constant, where exchange interactions dominate. For 3D magnonic crystals, characterized by small lattice constant, wide magnonic band gap is found. We show that the spatial distribution of different materials in magnonic crystals can be explored for tailored effective damping of spin waves.