Magnetic skyrmion lattice by the Fourier transform method
Magnetic skyrmion lattice by the Fourier transform method
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DOI：
10.1103/physrevb.99.134446
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发表时间：
2019-04-30
影响因子：
3.7
通讯作者：
Eschrig, Matthias
中科院分区：
文献类型：
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作者：
Balkind, Eugene;Isidori, Aldo;Eschrig, Matthias
我们展示了具有Dzyaloshinsky-Moriya相互作用的磁性材料中skyrmion晶格或螺旋序的理论研究的快速数值方法。该方法基于磁化强度的傅里叶展开，并结合傅里叶空间中磁性材料的自由能泛函的最小化，从而产生任何给定参数集的系统的最佳配置。我们采用拉格朗日乘法器技术来满足微磁约束。我们将这种方法应用于一个系统，根据参数的选择，显示铁磁性，斯基子晶格，或螺旋（螺旋）顺序。已知的临界场对应于螺旋-斯基米子以及斯基米子-铁磁体相变具有高精度的再现。利用这一数值方法，我们预测了skyrmion晶格的新型激发态（亚稳态），这些态可以通过与超导涡旋晶格耦合来稳定。该方法可以很容易地适用于其他微磁系统。
We demonstrate a fast numerical method of theoretical studies of skyrmion lattice or spiral order in magnetic materials with Dzyaloshinsky-Moriya interaction. The method is based on the Fourier expansion of the magnetization combined with a minimization of the free-energy functional of the magnetic material in Fourier space, yielding the optimal configuration of the system for any given set of parameters. We employ a Lagrange multiplier technique in order to satisfy micromagnetic constraints. We apply this method to a system that exhibits, depending on the parameter choice, ferromagnetic, skyrmion lattice, or spiral (helical) order. Known critical fields corresponding to the helical-skyrmion as well as the skyrmion-ferromagnet phase transitions are reproduced with high precision. Using this numerical method we predict new types of excited (metastable) states of the skyrmion lattice, which may be stabilized by coupling the skyrmion lattice with a superconducting vortex lattice. The method can be readily adapted to other micromagnetic systems.