Mirror symmetry breaking through an internal degree of freedom leading to directional motion - art. no. 031110

We analyze here the minimal conditions for directional motion (net flow in phase space) of a molecular motor placed on a mirror-symmetric environment and driven by a center-symmetric and time-periodic force field. The complet e characterization of the deterministic limit of the dissipative dynamics o f several realizations of this minimal model reveals a complex structure in the phase diagram in parameter space, with intertwined regions of pinning (closed orbits) and directional motion. This demonstrates that the mirror s ymmetry breaking, which is needed for directional motion to occur, can oper ate through an internal degree of freedom coupled to the translational one.