Spin-Polarized Currents in Double Quantum Dots with Rashba Spin-Orbit Interactions

Abstract

We propose a new scheme of realizing spin-polarized currents in a double quantum dot system. In the presence of Rashba spin-orbit coupling interactions and different Zeeman splittings of each quantum dot, the currents are spin-polarized. The polarization can be controlled by tuning the strength of Rashba spin-orbit coupling and external magnetic fields, which can produce nearly 100% spin-polarized currents. Furthermore, we explain and analyze the mechanism of the strongly spin-polarized currents. Lastly we give two phase diagrams to display our results.

Spin flip in single quantum ring with Rashba spin–orbit interation

“…Nowadays much of research in semiconductor spintronics has been shifting toward the field of the Rashba spinorbit interaction (RSOI) [1] in low dimensional semiconductor structures. [2][3][4][5][6][7][8][9] Many low dimensional semiconductor structures with RSOI have been intensively studied, [10][11][12][13] and these structures are expected to be potential spin devices, such as spin-inverter or spin-polarizer. In these quantum structures, spin transport is a basic problem, so many investigations focus on ballistic macroscopic circular rings [14][15][16][17][18][19][20] as its one dimensional Hamiltonian.…”