SUPERCONDUCTIVITY IN A SPIN LIQUID - A ONE-DIMENSIONAL EXAMPLE

We study a one-dimensional model of conduction electrons with a twofol d-degenerate band away from half filling interacting via the Coulomb r epulsion and Hund's rule coupling. We show that such a system has a di vergent Cooper pair susceptibility at T = 0, provided the Coulomb inte raction U between electrons on the same orbital and the modulus of the Hund's exchange integral \J\ are larger than the interorbital Coulomb interaction. The superconductivity can be achieved for any sign of J, The opening of spectral gaps makes this state stable with respect to direct electron hopping between the orbitals. The scaling dimension of the superconducting order parameter lies between 1/4 (small U) and 1/ 2 (large U). Possible experimental realizations of such systems are di scussed.