  We study persistent currents for interacting one-dimensional bosons on a
tight ring trap, subjected to a rotating barrier potential, which induces an
artificial U(1) gauge field. We show that, at intermediate interactions, the
persistent current response is maximal, due to a subtle interplay of effects
due to the barrier, the interaction and quantum fluctuations. These results are
relevant for ongoing experiments with ultracold atomic gases on mesoscopic
rings.
