Kondo effect on tunneling currents in a mesoscopic ring

We study the effect of the Kondo resonance on the tunneling current oscillations in a mesoscopic ring with a quantum dot, threaded by an external magnetic flux. Two situations are considered: the isolated ring and the ring connected to two external contacts. The system is described by an Anderson impurity tight-binding Hamiltonian where the electron-electron interaction is restricted to the dot. It is shown that at low temperature, even with the system out of resonance, the Kondo peak provides a channel for the electron to tunnel through the dot giving rise to persistent currents, for the isolated ring and to the Bohm-Aharonov oscillations, for the ring electrically connected. (orig.)