Spin-split states in aromatic molecules and superconductors

A state where spin currents exist in the absence of external fields has recently been proposed to describe the superconducting state of metals. It is proposed here that such a state also describes the ground state of aromatic molecules. It is argued that this point of view provides a more natural explanation for the large diamagnetic susceptibilities and NMR shifts observed in these molecules than the conventional viewpoint, and it provides a unified description of aromatic molecules and superconductors as sought by F. London. A six-atom ring model is solved by exact diagonalization and parameters in the model where a ground state spin current exists are found. We suggest that this physics plays a key role in biological matter.