INTERACTING ELECTRONS IN MESOSCOPIC RINGS

We show that in one dimension and at zero temperature, the persistent current without impurity scattering is the same without and with Coulomb interaction, and present the generalization of this result to two (or three) dimensions. When impurity scattering is included, the persistent current for electrons with Coulomb interaction is shown to be larger in magnitude than for non-interacting ones. Qualitative estimates show that an increase by a few orders of magnitude is possible. Numerical calculations in one dimension provide evidence for a Coulomb-driven enhancement back close to the ideal-ring value.