Controlling spin-polarized electron transport through a molecule: The role of molecular conformation

We investigate theoretically the spin-polarized electron transport through a complex organic molecule coupled to magnetic contacts. Our focus is on how low-energy deformations of the molecule affect the current-voltage characteristics and the magnetotransport of this molecular-scale device. We find that fairly modest deformations, costing only a few tens of meVs, can substantially change the tunneling current---by factors of 2 or more. Such deformations have still larger impact on the magnetoresistance, with small changes in molecular conformation even leading to changes in the sign of the magnetoresistance.