Coupled Brownian motors on a tilted washboard

Abstract

We consider globally coupled particles, each of them governed by a deterministic relaxation dynamics in a critically tilted washboard potential, but without a preferential spatial direction for the coupled system as a whole. For weak-to-moderate coupling we observe a spontaneous breaking of the system intrinsic symmetry which entails a spontaneous collective transport via a ratchet effect, possibly with a superimposed oscillatory long time behavior. For strong coupling, spontaneous symmetry breaking and spontaneous directed current are ruled out, whereas a negative mobility in response to an externally applied force is recovered.