Geometry of the chirality-induced spin selectivity effect

Using scanning tunneling microscopy, and a careful selection of chiral molecules and anchoring groups, we systematically carried out a series of magnetoresistance experiments. We observed a reversal of the signal upon changing the magnetization direction, the molecular chirality, and the molecular orientation. The orientation of the molecules and the magnetization of the substrate are vectors, and by associating an axial vector with the molecule, the observations can be explained. Other recent experiments, among them null experiments showing no CISS related magnetoresistance can be explained using our framework. The physical interpretation is, that the polar electrical polarization of the molecule cannot play a direct role, while the axial magnetic polarization vector operator is a much more realistic candidate. This vector plays an important role in the creation of a magnetic moment in the interface between molecule and metallic lead.