铁磁/半导体(绝缘体)/铁磁异质结中渡越时间与两铁磁层磁矩夹角变化的关系

在群速度概念的基础上, 研究了自旋极化电子隧穿通过铁磁体/半导体(绝缘体)/铁磁体异质结时, 渡越时间随两端铁磁层中磁矩夹角变化的关系. 研究结果表明: 当中间层为半导体层时, 由于半导体层中的Rashba自旋轨道耦合强度的影响, 自旋向上电子和自旋向下电子的渡越时间差会在两铁磁层相对磁矩夹角为π/2和3π/2附近出现一个极小值. 当中间层为绝缘体层时, 势垒高度的变化会导致不同取向的自旋极化电子渡越时间差的变化, 并当势垒高度超过一临界值时发生翻转.关键词：铁磁体/半导体(绝缘体)/铁磁体异质结Rashba自旋轨道耦合强度渡越时间磁矩

Relations between traversal time in ferromag-netic/semiconductor(insulator)/ferromagnetic heterojunction and the relative magnetic moment angle in two ferromagnetic layers

Based on the concept of group velocity, the relations between traversal time of spin-polarized electrons in ferromagnetic/semiconductor(insulator)/ferromagnetic heterojunction and relative magnetic moment angle in two ferromagnetic layers are studied. The results show that when the middle layer is semiconductor layer, influenced by the Rashba spin-orbit coupling, the minimum transverse times difference between the spin-up and down electrons can appear if the relative angle values in two ferromagnetic layers are nearly the π/2 and 3π/2, respectively. When the middle layer is insulator, the transverse time difference between the different spin orientations can be varied with the potential barrier heights and flip if the height exceeds a critical value.
Keywords：ferromagnetic/semiconductor(insulator)/ferromagnetic heterojunctionRashba spin-orbit couplingtraversal timemagnetic moment