论文标题
dyco $ _ {5} $，co $ _ {32} $ _ {32} $ _ {68} $和gd $ _ {27} $ _ {27} $ fe $ _ {73} $薄膜从DC到40 THZ
Frequency-independent terahertz anomalous Hall effect in DyCo$_{5}$, Co$_{32}$Fe$_{68}$ and Gd$_{27}$Fe$_{73}$ thin films from DC to 40 THz
论文作者
论文摘要
异常霍尔效应（AHE）是一种基本的自旋电荷到电荷转换现象，并且与自旋霍尔效应的旋转电流转换密切相关。未来的高速自旋设备将至关重要地依赖于Terahertz（THZ）频率的这种转换效应。在这里，我们透露，在三种技术相关的磁性材料的薄膜中，AHE仍然可以从DC到40 THz，均具有平坦的频率响应：Dyco $ _ {5} $，CO $ _ {32} $ _ {32} $ _ {32} $ fe $ _ {68} $和gd $ _ {27} $ _ {27} $ fe $ _ {73} $ {73} $ {73} $。我们测量频率依赖的电导率调度元件$σ_{xx} $和$σ_{yx} $，并与直流测量找到良好的一致性。我们的实验发现与COFE的$σ_{Yx} $的Ab-Initio计算完全一致，并突出了金属薄膜的大drude散射率（〜100 thz）的作用，该薄膜涂抹了THZ AHE的任何清晰的光谱特征。最后，我们发现对THZ AHE的固有贡献在CO $ _ {32} $ fe $ _ {68} $样本的外部机制上占主导地位。结果表明，AHE和相关效应（例如自旋霍尔效应）是未来THZ Spintronic设备的高度有希望的成分，可靠地从DC到40 THZ及以后运行。
The anomalous Hall effect (AHE) is a fundamental spintronic charge-to-charge-current conversion phenomenon and closely related to spin-to-charge-current conversion by the spin Hall effect. Future high-speed spintronic devices will crucially rely on such conversion effects at terahertz (THz) frequencies. Here, we reveal that the AHE remains operative from DC up to 40 THz with a flat frequency response in thin films of three technologically relevant magnetic materials: DyCo$_{5}$, Co$_{32}$Fe$_{68}$ and Gd$_{27}$Fe$_{73}$. We measure the frequency-dependent conductivity-tensor elements $σ_{xx}$ and $σ_{yx}$ and find good agreement with DC measurements. Our experimental findings are fully consistent with ab-initio calculations of $σ_{yx}$ for CoFe and highlight the role of the large Drude scattering rate (~100 THz) of metal thin films, which smears out any sharp spectral features of the THz AHE. Finally, we find that the intrinsic contribution to the THz AHE dominates over the extrinsic mechanisms for the Co$_{32}$Fe$_{68}$ sample. The results imply that the AHE and related effects such as the spin Hall effect are highly promising ingredients of future THz spintronic devices reliably operating from DC to 40 THz and beyond.
