  This work reports the existence of Isoperiodic Stable Ratchet Transport
Structures in the parameter spaces dissipation versus spatial asymmetry and
versus phase of a ratchet model. Such structures were found [Phys. Rev. Lett.
106, 234101 (2011)] in the parameter space dissipation versus amplitude of the
ratchet potential and they appear to have generic shapes and to align
themselves along preferred directions in the parameter space. Since the ratchet
current is usually larger inside these structures, this allows us to make
general statements about the relevant parameters combination to obtain an
efficient ratchet current. Results of the present work give further evidences
of the suggested generic properties of the isoperiodic stable structures in the
context of ratchet transport.
