The persistent current in frustrated Hubbard model

The persistent current on two-dimensional Hubbard model is investigated wit h the frustration by external magnetic field which is uniform and perpendic ular to the plane. Based on the Neel state as a ground state, the mean fiel d calculation shows the suppression of the persistent current by on-site Co ulomb repulsion U. We calculate the persistent current as changing singular flux phi (1) and show the suppression of the current vs. the flux quanta p er plaquette f. The dependence of f on this suppression shows local minima at even denominator of f and local maxima at odd denominator.