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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
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