论文标题
微磁和原子自旋模型中磁各向异性场的广义形式
Generalised form of the magnetic anisotropy field in micromagnetic and atomistic spin models
论文作者
论文摘要
我们提出了一种有效各向异性场的推导的一般方法，该方法根据Landau-Lifshitz-Gilbert方程来确定磁旋转的动力学行为。该方法基于球形极坐标中的梯度，最终结果在笛卡尔坐标中表达，通常在原子和微磁模型计算中使用。该方法通常对于各向异性阶的所有顺序都是有效的，包括在功能性磁性材料（例如永久磁铁）和新兴类别的抗铁磁材料中经常发现的方位角和旋转各向异性的高阶组合，并在Spintrotics中应用。各向异性用球形谐波表示具有理性温度缩放的重要特性。为各向异性提供了有效的场矢量，最多可达第六阶，为在数值模拟中实现高阶磁动体的统一框架提供了统一的框架。
We present a general approach to the derivation of the effective anisotropy field which determines the dynamical behaviour of magnetic spins according to the Landau-Lifshitz-Gilbert equation. The approach is based on the gradient in spherical polar coordinates with the final results being expressed in Cartesian coordinates as usually applied in atomistic and micromagnetic model calculations. The approach is generally valid for all orders of anisotropies including higher order combinations of azimuthal and rotational anisotropies often found in functional magnetic materials such as permanent magnets and an emerging class of antiferromagnetic materials with applications in spintronics. Anisotropies are represented in terms of spherical harmonics which have the important property of rational temperature scaling. Effective field vectors are given for anisotropies up to sixth order, presenting a unified framework for implementing higher order magnetic anisotropies in numerical simulations.
