Institute for Theoretical Physics and Astrophysics, University of Würzburg, D-97074 Würzburg, Germany.
Phys Rev Lett. 2013 May 31;110(22):226802. doi: 10.1103/PhysRevLett.110.226802. Epub 2013 May 29.
Using a generalized wave matching method we solve the full scattering problem for quantum spin Hall insulator-superconductor (SC)-quantum spin Hall insulator junctions. We find that for systems narrow enough so that the bulk states in the SC part couple both edges, the crossed Andreev reflection (CAR) is significant and the electron cotunneling (T) and CAR become spatially separated. We study the effectiveness of this separation as a function of the system geometry and the level of doping in the SC. Moreover, we show that the spatial separation of both effects allows for an all-electrical measurement of CAR and T separately in a five-terminal setup or by using the spin selection of the quantum spin Hall effect in an H-bar structure.
我们使用广义波匹配方法解决了量子自旋霍尔绝缘体-超导体（SC）-量子自旋霍尔绝缘体结的全散射问题。我们发现，对于足够窄的系统，SC 部分中的体状态耦合两个边缘，交叉安德烈夫反射（CAR）是显著的，并且电子库仑隧道（T）和 CAR 变得空间分离。我们研究了这种分离作为系统几何形状和 SC 中掺杂水平的函数的有效性。此外，我们表明，这两种效应的空间分离允许在五端设置中分别对 CAR 和 T 进行全电测量，或者在 H -bar 结构中利用量子自旋霍尔效应的自旋选择进行测量。
