Ratchet like motion of ac driven topological solitons

We report on the possibility of the ratchet-like (unidirectional) motion of a topological soliton of a dissipative Klein-Gordon equation in the presence of AC forces with zero mean. The role played by the temporal symmetry of the system in establishing soliton DC motions is emphasized. In particular, we show that effective soliton transport is achieved when the asymmetrical internal mode of the kink and the external force get phase locked. The dependence of the soliton velocity on different system parameters has been studied.