论文标题
旋转轨道耦合依赖性对自旋数据包漂移速度的实验分析
Experimental analysis of the spin-orbit coupling dependence on the drift velocity of a spin packet
论文作者
论文摘要
在托有两个子带的宽GAAS量子井中托有二维电子气体中研究了自旋传输。使用空间和时间Kerr旋转显微镜在平面内加速电场下图像漂移旋转数据包，在泵探针构型中实现了光学注射和自旋极化的检测。实验数据表现出高自旋迁移率和长期自旋寿命，允许获得自旋轨道的旋转速度的函数。出乎意料的是，高于0.4V/cm的中度电场高于2 $ m $ m/ns，我们观察到散装和结构相关的自旋轨道相互作用的依赖性对速度幅度。一个显着的特征是，当速度提高到10 $μm/ns时，立方dresselhaus项将大约一半的线性耦合增加到一半。相反，两个子带的RASHBA耦合在同一范围内降低到其值的一半。这些结果为在旋转轨道场中应用漂移模型以及旋转晶体管操作的局限性提供了新的信息。
Spin transport was studied in a two-dimensional electron gas hosted in a wide GaAs quantum well occupying two subbands. Using space and time Kerr rotation microscopy to image drifting spin packets under an in-plane accelerating electric field, optical injection and detection of spin polarization were achieved in a pump-probe configuration. The experimental data exhibited high spin mobility and long spin lifetimes allowing to obtain the spin-orbit fields as a function of the spin velocities. Surprisingly, above moderate electric fields of 0.4V/cm with velocities higher than 2$μ$m/ns, we observed a dependence of both bulk and structure-related spin-orbit interactions on the velocity magnitude. A remarkable feature is the increase of the cubic Dresselhaus term to approximately half of the linear coupling when the velocity is raised to 10$μ$m/ns. In contrast, the Rashba coupling for both subbands decreases to about half of its value in the same range. These results yield new information for the application of drift models in spin-orbit fields and about limitations for the operation of spin transistors.
