Control and detection of spin dynamics in semiconductor/ferromagent hybrid structures

我们制作了具有垂直磁化的CoFeB/MgO/GaAs磁性隧道结的三端子器件，并进行了磁输运和克尔显微镜测量，以阐明在GaAs半导体中自旋积累的产生和检测。在磁输运测量中，我们观察到了典型的Hanle效应。然而，在克尔显微镜测量中，即使在强的面内磁场BX=/-2.0T的情况下，克尔旋转信号仍然存在。结果表明，在垂直自旋注入中，氧化镁和砷化镓之间的界面起着至关重要的作用。

We fabricated three-terminal devices which have a CoFeB/MgO/GaAs magnetic tunnel junction with perpendicular magnetization, and performed magnetotransport and Kerr microscopy measurements to clarify the generation and detection of spin accumulation in GaAs semiconductors. In magnetotransport measurements, we observed typical Hanle effect. However, in Kerr microscopy measurements, the Kerr rotation signal remains even in high in-plane magnetic fields : Bx =+/- 2.0 T. The results suggest that the interface between MgO and GaAs plays crucial role for perpendicular spin injection.