Tunneling magnetoresistance effect in ferromagnet-quantum dot-ferromagnet system

We study the tunneling magnetoresistance(TMR) effect in Ferromagnet-quantum dot-Ferromagnet (FM-QD-FM) system by nonequilibrium Green's functions (NGF) method. From the study of TMR-eV curves, we find that the linewidth function has huge influence on the tunneling magnetoresistance effect. The tunneling magnetoresistance effect is also influenced by the relative angle of magnetic moment in the ferromagnetic leads in the quantum dot system. (paper)