Fig. 1
From: Tunable giant magnetoresistance in a single-molecule junction
A tunable single-molecule device in the STM junction. a and b Schematics of the electron transport process through an FePc molecule adsorbed on a Au(111) surface at different magnetic fields. The Au substrate and STM tip are the two terminals of the single-molecule device. The magnetic field can be viewed as a gate to control the molecular spin states. The arrays of green lines indicate the magnetic field lines. During the electron transport through the FePc, the tunneling electron has two possible passages corresponding to two molecular orbitals (\(d_{z^2} \) or dxz/dyz). At weak magnetic field as in a, the spin direction of Fe is in plane and currents flow by the dxz/dyz orbital. At strong magnetic field as in b, Fe spin is aligned to the magnetic field and electrons tunnel preferentially through the \(d_{z^2} \) orbital
