The spin-Hall effect (SHE) is found to be strong in heavy transition metals, such as Ta and W, in their amorphous and/or high resistivity form. In this paper, we show that by employing a Cu-Ta binary alloy as a buffer layer in an amorphous $\mathrm{C}{\mathrm{u}}_{100-x}\mathrm{T}{\mathrm{a}}_x$-based magnetic heterostructure with perpendicular magnetic anisotropy, the SHE-induced dampinglike spin-orbit torque (DL-SOT) efficiency $|{\xi }_{\mathrm{DL}}|$ can be tuned linearly by adjusting the buffer layer resistivity. Current-induced SOT switching can also be achieved in these $\mathrm{C}{\mathrm{u}}_{100-x}\mathrm{T}{\mathrm{a}}_x$-based magnetic heterostructures, and we find the switching behavior better explained by a SOT-assisted domain-wall propagation picture. Through systematic studies on $\mathrm{C}{\mathrm{u}}_{100-x}\mathrm{T}{\mathrm{a}}_x$-based samples with various compositions, we determine the lower bound of spin-Hall conductivity $|{\sigma }_{\mathrm{SH}}|\approx 2.02\times {10}^4\left[\hslash /2e\right]{\mathrm{\Omega }}^{-1}{\mathrm{m}}^{-1}$ in the Ta-rich regime. Based on the idea of resistivity tuning, we further demonstrate that $|{\xi }_{\mathrm{DL}}|$ can be enhanced from 0.087 for pure Ta to 0.152 by employing a resistive TaN buffer layer.

中文翻译：

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Cu-Ta二元合金异质结构中可调谐的自旋轨道转矩

发现在非晶态和/或高电阻率形式的重过渡金属（例如Ta和W）中，自旋霍尔效应（SHE）较强。在本文中，我们证明了通过使用Cu-Ta二元合金作为非晶态中的缓冲层$\mathrm{C}{\mathrm{ü}}_{100-X}\mathrm{Ť}{\mathrm{一个}}_X$垂直磁各向异性的基体磁异质结构，SHE诱导的阻尼似自旋轨道转矩（DL-SOT）效率 $|{\xi }_{\mathrm{DL}}|$通过调节缓冲层的电阻率可以线性调整。在这些情况下，也可以实现电流感应式SOT开关$\mathrm{C}{\mathrm{ü}}_{100-X}\mathrm{Ť}{\mathrm{一个}}_X$磁异质结构，我们发现开关行为可以更好地解释由SOT辅助畴壁传播图片。通过对$\mathrm{C}{\mathrm{ü}}_{100-X}\mathrm{Ť}{\mathrm{一个}}_X$各种成分的样品，我们确定了自旋霍尔电导率的下限 $|{\sigma }_{\mathrm{SH}}|\approx 2.02\times {10}^4\left[\hslash /\mathrm{2个}Ë\right]{\mathrm{\Omega }}^{-\mathrm{1个}}{\mathrm{米}}^{-\mathrm{1个}}$在塔富国政权中。基于电阻率调整的思想，我们进一步证明了$|{\xi }_{\mathrm{DL}}|$ 通过采用电阻性TaN缓冲层，可以将纯Ta的0.087增强到0.152。