Phase locking effect of persistent currents in mesoscopic Anderson-Hubbardrings

The effects of the Anderson impurities as well as weak electron-electron in teractions on the persistent current in a mesoscopic ring are studied by us ing the Anderson-Hubbard model. In this system, the single-particle energy spectrum possesses a flat band and the s-d hybridization plays an interesti ng role in the phase dependence of the persistent current. In the weak s-d hybridization, the phases can be locked for different electron numbers. Thi s phase locking effect originates from the existence of the flat band. In a ddition, it is found from the mean field approach that weak electron-electr on interactions lead to the spin splitting of the Energy band and the shift of the electron number for the phase locking effect.