Micromagnetic modeling of magnetic domain walls in curved cylindrical nanotubes and nanowires
Micromagnetic modeling of magnetic domain walls in curved cylindrical nanotubes and nanowires
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DOI：
10.1063/5.0050872
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发表时间：
2021-03
影响因子：
4
通讯作者：
L. Skoric;Claire Donnelly;C. Abert;Aurelio Hierro-Rodriguez;Dieter Suess;A. Fernández-Pacheco
中科院分区：
文献类型：
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作者：
L. Skoric;Claire Donnelly;C. Abert;Aurelio Hierro-Rodriguez;Dieter Suess;A. Fernández-Pacheco
我们研究了曲率对弯曲圆柱形纳米管和纳米线中磁区壁构型的能量和稳定性的影响。我们利用微磁模拟计算了管内横壁(TW)和涡壁(VW)态的相图，得到了这两种壁态的基态构型和亚稳区。曲率的引入使TW作为基态域壁的范围向更大的直径移动，并增加了亚稳态的范围。我们认为这种行为主要是由于交换能量中的曲率诱导的有效Dzyaloshinskii-Moriya项所致。此外，我们在实心圆柱形纳米线中定性地展示了相同的行为。比较了管和线，我们观察到，在管中，曲率倾向于抑制从TW到VW的转变，而在线中，它如何促进含有Bloch点的VW向TW的转变。这些发现对于从根本上理解三维几何中的磁区壁，以及设计未来的磁区壁器件具有重要的意义。
We investigate the effect of curvature on the energy and stability of domain wall configurations in curved cylindrical nanotubes and nanowires. We use micromagnetic simulations to calculate the phase diagram for the transverse wall (TW) and vortex wall (VW) states in tubes, finding the ground state configuration and the metastability region where both types of walls can exist. The introduction of curvature shifts the range for which the TW is the ground state domain wall to higher diameters, and increases the range of metastability. We interpret this behavior to be primarily due to the curvature-induced effective Dzyaloshinskii-Moriya term in the exchange energy. Furthermore, we demonstrate qualitatively the same behavior in solid cylindrical nanowires. Comparing both tubes and wires, we observe how while in tubes curvature tends to suppress the transformation from the TW to VW, in wires it promotes the transformation of the VW containing the Bloch point into the TW. These findings have important implications in the fundamental understanding of domain walls in 3D geometries, and the design of future domain wall devices.