Dissipative solitons, wave asymmetry and dynamical ratchets

Unidirectional solitonic wave-mediated transport is shown to be possible for a class of anharmonic lattice problems where, due to wave asymmetry, the waves can be used as a traveling periodic ratchet. Using a (mesoscopic) probabilistic description we have assessed the role of both viscous friction and temperature in both the direction of transport and its quantitative features. No asymmetry is required on the potential. Furthermore its actual form and even that of the periodic wave, save its asymmetry, play no significant role in the results obtained and hence they exhibit rather universal value. (c) 2006 Elsevier B.V. All rights reserved.