论文标题
光学频率的巨型自旋效果
The Giant Spin Hall Effect at Optical Frequencies
论文作者
论文摘要
我们将旋转角度概括为线性响应方案中有限频率的激光脉冲，并预测了巨大的光学旋转效果。也就是说，对于某些过渡金属元件，在特定频率下，自旋电流可能是电荷电流的很大一部分，甚至超过了XUV频率。通过最大化旋转电流，同时最大程度地减少电荷电流，我们就可以最大程度地减少自旋设备中的主要加热来源。我们采用{\ it ab-initio}时间依赖性密度功能理论（TDDFT），并且使用实时模拟计算所有$ 3 $ d，$ 4 $ d，$ 4 $ d和$ 5 $ d的过渡金属的电导率和横向自旋电导率，用于$ 50 $ 50 $ ev的频率。在XUV频率范围内，我们发现旋转厅角度大于$ 1 $的值，表明可以生成大于电荷电流的旋转电流。
We generalize the spin Hall angle to laser pulses of finite frequencies in the linear response regime and predict a giant optical spin Hall effect. Namely, for certain transition metal elements, at particular frequencies, the spin current can be a significant fraction of the charge current, and even exceed it for XUV frequencies. By maximizing spin current while minimizing the charge current, we thus minimize a major source of heating in spintronic devices. We employ {\it ab-initio} time-dependent density functional theory (TDDFT), and with real-time simulations calculate the conductivity and transverse spin conductivity for all $3$d, $4$d, and $5$d transition metals for frequencies up to $50$ eV. In the XUV frequency range we find values greater than $1$ for the spin Hall angle, indicating spin currents larger than the charge current can be generated.
