The effect of the Coulomb interaction on the mesoscopic persistent current

The persistent current in three-dimensional mesoscopic rings is investigated numerically. The model is tight-binding one with random site-energies and interaction between electrons. The self-consistent Hartree-Fock approximation is adopted for the interaction between electrons, and models with up to $6\times 6\times 20$ sites are investigated. It is shown that the long-range Coulomb interaction enhances the persistent current for rings with finite width. The origin of the enhancement is discussed.