Magnetic skyrmions are topological spin textures with nanoscale size, which have great potential for spintronics applications. However, they are very sensitive to film thicknesses and interfaces in ultrathin films or multilayer heterostructures, and methods to generate and tune skyrmions are needed in order to use them in real-world applications. Electric field gating has been shown to modify the magnetic characteristics of thin films; however, these changes are limited by the low electric fields achievable using solid gate electrodes. In this work, we use ionic liquid gating to modify the magnetic characteristics of perpendicularly magnetized $\mathrm{Mg}\mathrm{O}$/$\mathrm{Mn}$${}_2$$\mathrm{Co}\mathrm{Al}$/$\mathrm{Pd}$ ultrathin films, applying a range of voltage sequences to generate skyrmions through both nonvolatile and volatile changes to these films. We achieve a giant anisotropy field tunability of 109.8 mT ${\mathrm{V}}^{-1}$ that is nonreversible, which can be ascribed to magneto-ionic effects. Reversible changes to the anisotropy and volatile skyrmion formation are achieved via electrostatic charge accumulation, which could induce an in-plane Rashba field. Our results strongly demonstrate that ionic liquid gating is a versatile method to engineer both nonvolatile and volatile skyrmions by tuning the magnetic characteristics of films to the regimes where they can exist.

中文翻译：

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通过超薄膜中的离子液体门控设计的非易失性和易失性 Skyrmion 生成

磁性斯格明子是具有纳米级尺寸的拓扑自旋纹理，在自旋电子学应用中具有巨大的潜力。然而，它们对超薄膜或多层异质结构中的薄膜厚度和界面非常敏感，需要生成和调整斯格明子的方法才能在实际应用中使用它们。电场门控已被证明可以改变薄膜的磁特性；然而，这些变化受到使用固体栅电极可实现的低电场的限制。在这项工作中，我们使用离子液体门控来修改垂直磁化的磁特性$镁\mathrm{哦}$/$锰$${}_2$$\mathrm{公司}铝$/$钯$超薄膜，通过对这些薄膜的非易失性和易失性变化，施加一系列电压序列以生成斯格明子。我们实现了 109.8 mT 的巨大各向异性场可调性 ${\mathrm{伏}}^{-1}$这是不可逆的，这可以归因于磁离子效应。各向异性和挥发性斯格明子形成的可逆变化是通过静电荷积累实现的，这可能会引起面内 Rashba 场。我们的结果有力地证明，离子液体门控是一种通用的方法，可以通过将薄膜的磁特性调整到它们可以存在的范围来设计非挥发性和挥发性斯格明子。