论文标题
具有原子分辨率的微米尺度拓扑性手性磁状态的寿命
The lifetime of micron scale topological chiral magnetic states with atomic resolution
论文作者
论文摘要
已经开发了一种用于谐波过渡状态理论（HTST）中磁状态寿命的数值计算的新方法。在最简单的情况下，该系统由具有短距离相互作用的Heisenberg样哈密顿量描述。计算在笛卡尔坐标中进行。使用Lagrange乘数考虑了对磁矩值的限制。 HTST中Arrhenius定律中指的指数因子是根据最小值和多维能量表面上的Minima和鞍点的Hessian的决定因素编写的。提出了用于计算这些决定因素的算法，而无需搜索Hessian的特征值，但提出了使用递归关系的算法。该方法允许计算包含数百万磁矩的系统的决定因素。这使得可以计算指数前因子并估计具有原子分辨率的微米尺度拓扑结构的寿命，到目前为止，使用标准方法已经不可能。通过计算2D和3D Skyrmionic结构来证明该方法的准确性。
A new method for the numerical computation of the lifetimes of magnetic states within harmonic transition state theory (HTST) has been developed. In the simplest case, the system is described by a Heisenberg-like Hamiltonian with short-range interaction. Calculations are performed in Cartesian coordinates. Constraints on the values of magnetic moments are taken into account using Lagrange multipliers. The pre-exponential factor in the Arrhenius law in HTST is written in terms of the determinants of the Hessian of energy at the minima and saddle points on the multidimensional energy surface. An algorithm for calculating these determinants without searching for eigenvalues of the Hessian but using recursive relations is proposed. The method allows calculating determinants for systems containing millions of magnetic moments. This makes it possible to calculate the pre-exponential factor and estimate the lifetimes of micron-scale topological structures with atomic resolution, which until now has been impossible using standard approaches. The accuracy of the method is demonstrated by calculating 2D and 3D skyrmionic structures.
