We study current-induced deterministic magnetization switching and domain-wall motion via polar Kerr microscopy in all-amorphous ${\mathrm{W}}_{66}{\mathrm{Hf}}_{34}/\mathrm{Co}\text{−}\mathrm{Fe}\text{−}\mathrm{B}(\mathrm{CFB})/{\mathrm{Ta}\mathrm{O}}_x$ with perpendicular magnetic anisotropy and a large spin Hall angle. Investigations of magnetization switching as a function of the in-plane assist field and the current-pulse width yield switching-current densities as low as $3\times {10}^9{\mathrm{A}/\mathrm{m}}^2$. We accredit this low switching-current density to a low depinning-current density, which is obtained from measurements of domain-wall displacements upon current injection. This correlation is verified by investigations of a $\mathrm{Ta}$/$\mathrm{CFB}$/$\mathrm{Mg}\mathrm{O}$/$\mathrm{Ta}$ reference sample, which shows critical-current densities that are at least one order of magnitude larger.

中文翻译：

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全非晶W-Hf / Co-Fe-B / TaOx膜中的超低开关电流密度

我们通过极性Kerr显微镜研究全非晶态中电流诱导的确定性磁化转换和畴壁运动 ${\mathrm{w\; ^}}_{66}{\mathrm{高频}}_{34}/\mathrm{有限公司}\text{-}铁\text{-}\mathrm{乙}（\mathrm{循环流化床}）/{钽\mathrm{Ø}}_X$具有垂直的磁各向异性和大的自旋霍尔角。根据平面内辅助场和电流脉冲宽度进行磁化切换的研究得出的开关电流密度低至$3\times {10}^9{\mathrm{一种}/\mathrm{米}}^2$。我们将这种低开关电流密度定为低钉扎电流密度，这是通过在注入电流时测量畴壁位移获得的。这种相关性通过对$钽$/$\mathrm{循环流化床}$/$镁\mathrm{Ø}$/$钽$ 参考样品，其临界电流密度至少大一个数量级。