  We demonstrate that repulsive power law interactions can induce directed
transport of particles in dissipative, ac-driven periodic potentials, in
regimes where the underlying noninteracting system exhibits localized
oscillations. Contrasting the well-established single particle ratchet
mechanism, this interaction induced transport is based on the collective
behaviour of the interacting particles yielding a spatiotemporal nonequilibrium
pattern comprising persistent travelling excitations.
