Collective Current Rectification

We consider a network of coupled underdamped ac-driven dynamical units exposed to a heat bath. The topology of connections defines the absence/presence of certain spatial symmetries, which in turn cause nonzero/zero value of a mean dc-output. We discuss dynamical mechanisms of the rectification and identify dc-current reversals with synchronization/desynchronization transitions in the network dynamics.Comment: 3 fig

Dynamical mechanisms of DC current generation in driven Hamiltonian systems

Recent symmetry considerations (Phys. Rev. Lett. {\bf 84} 2358 (2000)) have shown that dc currents may be generated in the stochastic layer of a system describing the motion of a particle in a one-dimensional potential in the presence of an ac time-periodic drive. In this paper we explain the dynamical origin of this current. We show that the dc current is induced by the presence and desymmetrization of ballistic channels inside the stochastic layer. The existence of these channels is due to resonance islands with non-zero winding numbers. The characterization of the flights dynamics inside ballistic channels is described by distribution functions. We obtain these distribution functions numerically and find very good agreement with simulation data.Comment: 4 pages, 3 figure