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主要研究了平面一维波导系统中的Rashba电子波函数的输运性质,得到了如下的结果.根据Rashba效应,能量为E的平面电子波,将分裂成波矢分别为k1=k0+kδ与k2=k0-kδ的两种波函数,其自旋取向与波导的夹角分别为+π/2(自旋向上态)与+π/2(自旋向下态).若在支路的终端是栅极或者铁磁接触,则相应的波函数成为驻波形式exp(±ikδl)sin[k0(l-L)],其中L是支路的长度,l是支路内的坐标.与不考虑自旋的情况不同的是,Rashba电子波函数的相位与支路的取向角度θ有关.此外,两种自旋取向的波传播的群速度相同,都是-k0/m*.在各支路结点处,由波函数的连续性和流密度守恒条件,得到了Rashba电子波函数所必须满足的边界条件.利用这些边界条件,我们研究了Rashba电子在一些结构中的透射和反射性质,发现自旋向上和向下的Rashba电子波函数的干涉效应将受到铁磁接触或栅极的调制.最后得到了多分支结构中,Rashba电子输运的一般性理论.我们提出的Rashba电子的一维量子波导理论可以被用来设计各种自旋极化器件.
According to the Rashba effect, the plane electron wave with energy E is split into wave vectors k1 = k0 + kδ and k2 = k0-kδ, the angle between the spin orientation and the waveguide is + π / 2 (spin-up state) and + π / 2 (spin-down state) The terminal is a gate or a ferromagnetic contact, then the corresponding wave function becomes the standing wave form exp (± ikδl) sin [k0 (lL)], where L is the length of the branch and l is the coordinate within the branch. The difference between spins is that the phase of the Rashba electron wave function is related to the orientation angle θ of the branch. In addition, the velocities of the two spin-oriented waves propagate at the same velocity, both of -k0 / m * At the node, the boundary conditions necessary for the Rashba electron wave function are obtained by the continuity of the wave function and the conservation of the flow density. Using these boundary conditions, we study the transmission and reflection properties of Rashba electrons in some structures and find that The interference effect of the spin-up and down-directed Rashba electron wave functions will be modulated by the ferromagnetic contact or the gate. Finally, In the structure of Rashba, the general theory of electron transport Rashba’s one-dimensional quantum waveguide theory can be used to design a variety of spin-polarized devices.