Instability of skyrmions in magnetic fields
Instability of skyrmions in magnetic fields
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DOI：
10.1063/5.0013488
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发表时间：
2020-06
影响因子：
4
通讯作者：
Loic Mougel;P. M. Buhl;Ryohei Nemoto;T. Balashov;Marie Hervé;Julian Skolaut;T. Yamada;B. Dupé;W. Wulfhekel
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文献类型：
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作者：
Loic Mougel;P. M. Buhl;Ryohei Nemoto;T. Balashov;Marie Hervé;Julian Skolaut;T. Yamada;B. Dupé;W. Wulfhekel
在这项实验与理论相结合的工作中，我们报道了当施加面外磁场时Co/Ru（0001）系统中斯基子半径的演变及其破坏。在低场下，skyrmions是亚稳态的，并表现出椭圆不稳定性，其中沿短轴，自旋织构接近自旋-螺旋相，长轴膨胀以回到自旋-螺旋基态。在高场中，我们观察到有限大小的圆形天幕，直到坍缩场Bc，在那里它们被破坏，拓扑电荷被湮灭。我们通过基于密度泛函理论计算参数化磁化动力学模拟的数值方法估计了Bc，并将其与≈30 mK下的实验扫描隧道显微镜观察结果进行了比较。
In this combined experimental and theoretical work, we report on the evolution of the skyrmion radius and its destruction in the system Co/Ru(0001) when an out-of-plane magnetic field is applied. At low fields, skyrmions are metastable and display an elliptical instability in which along the short axis, the spin texture approaches that of the spin-spiral phase and the long axis expands in order to go back to the spin-spiral ground state. At high fields, we observe round skyrmions of finite size up to the collapse field Bc, where they are destroyed and the topological charge is annihilated. We estimate Bc via numerical methods based on magnetization dynamics simulations parametrized by density functional theory calculations and compare it to experimental scanning tunneling microscopy observations obtained at ≈ 30 mK.