Current reversals in deterministic ratchets: points and dimers

We address the problem of the chaotic transport of point particles and rigid dimers in an asymmetric periodic ratchet potential. When the inertial term is taken into account, the dynamics can be chaotic and modify the transport properties. By a comparison between the bifurcation diagram and the current, we identify the origin of the multiple current reversals as bifurcations, usually from a chaotic to a periodic regime. We consider the dynamics of rigid dimers, as a function of size, extending in this way our previous results for point particles.