论文标题
co $ _ {3} $ sn $ _ {2} $ s $ _ {2} $的旋转电荷转换效率的提高。
Enhancement of Spin-Charge Conversion Efficiency for Co$_{3}$Sn$_{2}$S$_{2}$ across Transition from Paramagnetic to Ferromagnetic Phase
论文作者
论文摘要
CO $ _ {3} $ sn $ _ {2} $ s $ _ {2} $（CSS）是Shandite化合物之一，成为磁性Weyl半磁性候选候选者，低于铁磁相过渡温度（$ \ \\ textit {t Textit {t} _ \ textrm {c} c} $）。在本文中，我们通过测量由CSS / CU / COFEB组成的Trilayer的旋转旋转型铁磁共振（ST-FMR）来研究CSS薄膜电荷电流和自旋电流之间转换的温度（$ \ textit {t} $）。以上$ \ textIt {t} _ \ textrm {c} $ 〜170 K，CSS / CU / COFEB Trilayer表现出来自comagnetic CSS和CoFeb的偏磁盘CSS和Anisotropic Magnetoresance（AMR）的旋转厅效应的透明ST-FMR信号。在$ \ textit {t} _ \ textrm {c} $下方，发现ST-FMR信号涉及直流电压（$ \ textit {v} _ \ textrm {dc} $），不仅是通过AMR，而且还通过巨型MagnEtoresistances（GMR）。因此，应考虑来自AMR和GMR的电阻变化，以正确理解$ \ textit {v} _ \ textrm {dc} $的特征场角依赖性。由铁磁CSS产生的自旋大厅扭矩具有与自旋效应相同的对称性，主要作用于COFEB的磁化。在$ \ textit {t} $ <$ <$ <$ \ textit {t} _ \ textrm {c} $上观察到自旋电荷转换效率（$ξ$）的一定提高，这表明相位过渡到铁磁CSS可以促进高效的自旋递送转换。此外，我们的理论计算显示了旋转厅电导率的增加，磁矩在$ \ textit {t} $ <$ <$ <$ \ textit {t} _ \ textrm {c} $中的出现与实验观察一致。
Co$_{3}$Sn$_{2}$S$_{2}$ (CSS) is one of the shandite compounds and becomes a magnetic Weyl semimetal candidate below the ferromagnetic phase transition temperature ($\textit{T}_\textrm{C}$). In this paper, we investigate the temperature ($\textit{T}$) dependence of conversion between charge current and spin current for the CSS thin film by measuring the spin-torque ferromagnetic resonance (ST-FMR) for the trilayer consisting of CSS / Cu / CoFeB. Above $\textit{T}_\textrm{C}$ ~ 170 K, the CSS / Cu / CoFeB trilayer exhibits the clear ST-FMR signal coming from the spin Hall effect in the paramagnetic CSS and the anisotropic magnetoresistance (AMR) of CoFeB. Below $\textit{T}_\textrm{C}$, on the other hand, it is found that the ST-FMR signal involves the dc voltages ($\textit{V}_\textrm{dc}$) not only through the AMR but also through the giant magnetoresistance (GMR). Thus, the resistance changes coming from both AMR and GMR should be taken into account to correctly understand the characteristic field angular dependence of $\textit{V}_\textrm{dc}$. The spin Hall torque generated from the ferromagnetic CSS, which possesses the same symmetry as that for spin Hall effect, dominantly acts on the magnetization of CoFeB. A definite increase in the spin-charge conversion efficiency ($ξ$) is observed at $\textit{T}$ < $\textit{T}_\textrm{C}$, indicating that the phase transition to the ferromagnetic CSS promotes the highly efficient spin-charge conversion. In addition, our theoretical calculation shows the increase in spin Hall conductivity with the emergence of magnetic moment at $\textit{T}$ < $\textit{T}_\textrm{C}$, which is consistent with the experimental observation.
