The profile of chiral skyrmions of small radius
The profile of chiral skyrmions of small radius
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DOI：
10.1088/1361-6544/ab81eb
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发表时间：
2020-07-01
期刊：
影响因子：
1.7
通讯作者：
Venakides, Stephanos
中科院分区：
文献类型：
--
作者：
Komineas, Stavros;Melcher, Christof;Venakides, Stephanos
手征Skyrmions是具有Dzyaloshinskiii-Moriya（DM）相互作用的铁磁体的Landau-Lifshitz方程的稳定粒子类解，由拓扑数表征。本文研究了轴对称Skyrmion的轮廓，在小DM参数（或大各向异性）的渐近极限下，给出了相应远场和近场方程的精确解。这两个领域的匹配导致一个公式的skyrmion半径作为DM参数的函数。导出的解决方案显示了不同的长度尺度，这是目前在skyrmion配置文件。因此，随着DM参数从零开始增加，这幅图是由半径无限小的Belavin-Polyakov解产生的手征Skyrmion。Skyrmion保留Belavin-Polyakov轮廓超过和远远超出核心之前，它假设一个指数衰减;轮廓的轴对称Belavin-Polyakov解决方案的单位度发挥作用的通用核心配置文件的手征Skyrmion。
Chiral skyrmions are stable particle-like solutions of the Landau-Lifshitz equation for ferromagnets with the Dzyaloshinskii-Moriya (DM) interaction, characterized by a topological number. We study the profile of an axially symmetric skyrmion and give exact formulae for the solution of the corresponding far-field and near-field equations, in the asymptotic limit of small DM parameter (alternatively large anisotropy). The matching of these two fields leads to a formula for the skyrmion radius as a function of the DM parameter. The derived solutions show the different length scales which are present in the skyrmion profiles. The picture is thus created of a chiral skyrmion that is born out of a Belavin-Polyakov solution with an infinitesimally small radius, as the DM parameter is increased from zero. The skyrmion retains the Belavin-Polyakov profile over and well-beyond the core before it assumes an exponential decay; the profile of an axially-symmetric Belavin-Polyakov solution of unit degree plays the role of the universal core profile of chiral skyrmions.