PERIODICITY AND KONDO EFFECT OF PERSISTENT CURRENTS IN MESOSCOPIC RINGS

We study the properties of persistent currents in mesoscopic rings in the ballistic regime considering the interaction between electrons in an exact way. We find that interactions favour the Fourier components with period smaller than phi(o) = hc/e (where phi(o) is the. flux quan tum)in the persistent current, yielding periodicities phi(o)/p where p is an interger in the range I < p < N-e (N-e is the number of particl es in the ring). In addition, we consider a system consisting of one r ing without interactions connected to a quantum well where Coulomb rep ulsion is not neglected. in this case, we analyze the effect of Coulom b blockade on the persistent current. Our results are interpreted as a competence between Coulomb blockade and Kondo effect The value of the persistent current in the ring is determinated by this competence.