Realization of Spin Switch in a Triple-Terminal Double-Quantum-Dot Structure

Electron transport through a triple-terminal double-quantum-dotstructure is theoretically studied. By adjusting the chemical potential in leads, two channels in this system are created, and in the presence of magnetic flux the conductances for the two channels present remarkable difference from each other. When the quantum dots are made of ferromagnetic materials, the levels of quantum dots are spin dependent, then spin polarization comes about in the two channels. Furthermore, in some regions spin polarization in the different channels are opposite. We consider that this model can bea device prototype for spin filtering and spin separation.