Interaction-induced enhancement and oscillations of the persistent current

The persistent current $I$ in integrable models of multichannel rings with both short- and long-ranged interactions is investigated. $I$ is found to oscillate in sign and increase in magnitude with increasing interaction strength due to interaction-induced correlations in the currents contributed by different channels. For sufficiently strong interactions, the contributions of all channels are found to add constructively, leading to a giant enhancement of $I.\mathrm{}$ Numerical results confirm that this parity-locking effect is robust with respect to intersubband scattering.