Significant interaction-induced enhancement of persistent currents in 2d disordered cylinders

The persistent current of small disordered 2D cylinders is calculated by an exact numerical diagonalization of a tight-binding interacting model Hamiltonian. A significant enhancement in the ensemble-averaged persistent current amplitude occurs for a certain range of electron-electron interaction strength. For similar ID and quasi-ID geometries no significant enhancement is observed. This current enhancement is due to the shift of the onset point of the Mott-Hubbard metal insulator transition. Our results may provide an explanation to a longstanding problem in mesoscopic physics, namely, the high values of persistent current measured in experiment.