Method for finding mechanism and activation energy of magnetic transitions, applied to skyrmion and antivortex annihilation
Method for finding mechanism and activation energy of magnetic transitions, applied to skyrmion and antivortex annihilation
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DOI：
10.1016/j.cpc.2015.07.001
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发表时间：
2015-11-01
影响因子：
6.3
通讯作者：
Jonsson, Hannes
中科院分区：
文献类型：
--
作者：
Bessarab, Pavel F.;Uzdin, Valery M.;Jonsson, Hannes
本文提出了一种寻找磁系统中跃迁最小能量路径的方法。该路径相对于磁矢量的取向进行优化，而它们的幅度是固定的或从单独的计算获得。通过以下方式考虑配置空间的曲率：（1）在优化期间使用测地线来评估系统的距离和位移，以及（2）将路径切线和磁力投影在由磁矢量的所有可能取向限定的流形的切线空间上。该方法，命名为测地线轻推弹性带（GNEB），并说明其实施与复杂的跃迁，包括湮灭和创建的skyrmion和antivortex状态的计算。后者的寿命内确定的谐波过渡态理论，使用非共线扩展的亚历山大-安德森模型。(C)2015 Elsevier B. V.版权所有。
A method for finding minimum energy paths of transitions in magnetic systems is presented. The path is optimized with respect to orientation of the magnetic vectors while their magnitudes are fixed or obtained from separate calculations. The curvature of the configuration space is taken into account by: (1) using geodesics to evaluate distances and displacements of the system during the optimization, and (2) projecting the path tangent and the magnetic force on the tangent space of the manifold defined by all possible orientations of the magnetic vectors. The method, named geodesic nudged elastic band (GNEB), and its implementation are illustrated with calculations of complex transitions involving annihilation and creation of skyrmion and antivortex states. The lifetime of the latter was determined within harmonic transition state theory using a noncollinear extension of the Alexander-Anderson model. (C) 2015 Elsevier B.V. All rights reserved.