Quantum loop current in a C(60) molecular bridge.

The existence of a quantum loop current in a C(60) molecular bridge is predicted using the Green's function method. The model for the molecular bridge consists of a C(60) molecule attached to one-dimensional conductive electrodes. It is shown that the loop current is related to the degeneracy of the energy levels of the C(60) molecule. Specific to this loop current is its magnitude which is much larger than that of the source-drain current. The associated magnetic moment also shows certain remarkable features such as its inversion with the energy across the molecular levels and the restriction of its direction onto a single plane.