  The controllability of charge transport through an organic molecular
spin-valve system is theoretically investigated on the basis of a
Su-Schrieffer-Heeger model combined with the non-equilibrium Green's function
formalism. We show how the formation of polaron in the organic sub-structure
leads to a hysteretic conductance switching, via sweeping either the bias
voltage or the electrochemical potential. We further obtain an exponential
dependence of the magnetoresistance as a function of the applied bias voltage.
The implications of calculated results in relation to experiments and device
applications are addressed and commented.
