Supercurrents in an atom-molecule gas in an optical ring lattice

Atom and molecule currents in a Fermi gas in the neighborhood of a Feshbach resonance are studied in a one-dimensional optical ring lattice by directly diagonalizing small models. A rotational analogy of flux quantization is used to show that fraction of the current is carried by particles with twice the mass of an atom, which suggests pairing and superfluidity.