Spin-dependent inelastic transport through single-molecule junctions with ferromagnetic electrodes

Using the nonequilibrium Green's function approach and taking into account contributions of both electron and hole, we investigate the spin-dependent carrier transport in a magnetic tunnel junction consisting of a molecular quantum dot coupled to two ferromagnetic leads and to a local vibrational mode. The calculated results show a remarkable influence of electron-phonon interaction and electron-electron interaction on spin-dependent density of states, charge current, and tunneling magnetoresistance (TMR). The oscillating TMR is attributed to the phonon-assisted resonant tunneling rather than the well-known charging effect. The behavior of the zero-bias TMR dip or peak depends to a great degree on whether the quantum dot is in the Kondo or non-Kondo regime.