Abstract : We theoretically study the nonlinear dynamics of atoms cooled and trapped in a dissipative optical lattice and particularly noise-induced, spontaneous and stimulated transport phenomena.
We separate two differently behaving classes of atoms, respectively trapped and un-trapped in the potential wells. This separation allows for the precise understanding of the behavior of the velocity distributions and of the properties of spontaneous transport (spatial diffusion) for parameters ranging from the jumping to the oscillating regimes.
We study stimulated transport phenomena in the intermediate regime between the jumping and oscillating regimes where the typical times for hamiltonian motion and dissipative processes have the same order of magnitude. We characterize the Brillouin propagation modes and the corresponding excitation mecanisms. We demonstrate that these show the phenomenon of stochastic resonance that corresponds to the synchronization of hamiltonian motion and dissipative processes. We finally study an atomic temporal ratchet originating from a temporal symmetry breaking-induced directed motion.