Effects of geometric Berry phase on persistent currents in large-U one-dimensional Hubbard rings

Abstract

By using the Bethe-Yang ansatz within the framework of the tight-binding model, the ground-state energy and the pesistent current in one-dimensional Hubbard rings are calculated in the presence of an AB flux accompanied by a local magnetic field whose direction varies in space. Analytical result are obtained for large-U limit. It is indicated that there usaually exists no short periodicity for the ground-state energy and persistent current due to the effect of the geometric Berry phase even for the case of infinite U. In a special case, the short periodicity retained in the zero-order approximation is broken down by taking into account the first-order energy correction for large but not infinite U. Moreover, it is found that in the strong-coupling limit, the electron-electron interaction suppresses the persistent current, which is in agreement with other numerical calculations. © 1995 The American Physical Society.