Ground state search, hysteretic behaviour, and reversal mechanism of skyrmionic textures in confined helimagnetic nanostructures.
Ground state search, hysteretic behaviour, and reversal mechanism of skyrmionic textures in confined helimagnetic nanostructures.
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DOI：
10.1038/srep17137
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发表时间：
2015-11-25
影响因子：
4.6
通讯作者：
Fangohr H
中科院分区：
文献类型：
--
作者：
Beg M;Carey R;Wang W;Cortés-Ortuño D;Vousden M;Bisotti MA;Albert M;Chernyshenko D;Hovorka O;Stamps RL;Fangohr H
磁Skyrmions有可能为低功耗，高密度数据存储和处理提供解决方案。开发基于skyrmion的器件的主要挑战之一是skyrmion在受限的螺旋磁性纳米结构中的磁稳定性。通过对平衡态的系统研究，使用包括退磁效应的全三维微磁模型，我们证明了skyrmionic纹理是在零外部磁场和磁晶各向异性的情况下helmagnetic薄膜纳米结构中的最低能量状态。我们还报道了非基态平衡构型的亚稳区域。我们发现，brackyrmionic纹理进行滞后行为之间的两个能量等效的skyrmionic状态具有不同的核心取向，即使在没有磁晶和退磁为基础的形状各向异性，这表明存在的Dzyaloshinskiii-Moriya为基础的形状各向异性。最后，我们表明，skyrmionic纹理核心反转动力学的布洛赫点的出现和传播。
Magnetic skyrmions have the potential to provide solutions for low-power, high-density data storage and processing. One of the major challenges in developing skyrmion-based devices is the skyrmions’ magnetic stability in confined helimagnetic nanostructures. Through a systematic study of equilibrium states, using a full three-dimensional micromagnetic model including demagnetisation effects, we demonstrate that skyrmionic textures are the lowest energy states in helimagnetic thin film nanostructures at zero external magnetic field and in absence of magnetocrystalline anisotropy. We also report the regions of metastability for non-ground state equilibrium configurations. We show that bistable skyrmionic textures undergo hysteretic behaviour between two energetically equivalent skyrmionic states with different core orientation, even in absence of both magnetocrystalline and demagnetisation-based shape anisotropies, suggesting the existence of Dzyaloshinskii-Moriya-based shape anisotropy. Finally, we show that the skyrmionic texture core reversal dynamics is facilitated by the Bloch point occurrence and propagation.