2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/140937We argue that a system of ultracold bosonic atoms in a tilted optical lattice can become superfluid in response to resonant AC forcing. Among others, this allows one to prepare a Bose-Einstein condensate in a state associated with a negative effective mass. Our reasoning is backed by both exact numerical simulations for systems consisting of few particles, and by a theoretical approach based on Floquet-Fock states.Accepted for publication in Europhysics letters, 6 pages, 4 figures, Changes in v2: reference 7 replaced by a more recent oneOther Condensed Mattertext