Abstract: In nonlinear periodic systems, the balance between nonlinearity and dispersion relation can generate spatially localized band-gap solitons. One of outstanding features of these solitons is that it is very difficult to move them. In this paper, we propose to spatially move band-gap solitons via the periodic modulation of periodic potentials. We first numerically find the stable band-gap solitons, then set them as initial states and let them to evolve with the modulation of relevant phase of periodic potentials. We find that if the modulation is slow enough, the band-gap solitons can be transported away with a very high fidelity. This work provides a possibly theoretical scheme to the transportation of band-gap solitons.

Key words: band-gap solitons, optical superlattice, Bose-Einstein condensate, fidelity