Spin-dependent current modulation in organic spintronics.

We investigate the spin-dependent current modulation in a model organic semiconductor sandwiched by two ferromagnetic electrodes. When the conductance band of the system is activated by an applied bias voltage, the majority-spin electrons are successively blocked within the organic semiconductor and form nonequilibrium polarons. This majority-spin blockage will modulate the minority-spin current due to the effective spin-spin coupling mediated by the electron-phonon interaction. This study suggests that the spin-blockage induced current modulation is a rather robust phenomenon in organic spintronics.