Atomic transport on one-dimensional optical lattices

We carry out quantum and semiclassical numerical simulations of the dynamics, particularly diffusion, of atoms in an optical lattice. We consider specifically the situation of a [Formula Presented] atomic transition, whose experimental counterpart can be realized in [Formula Presented] experiments. The semiclassical results, which cover a larger range of parameters than would be practical for fully quantum calculations, confirm and extend the work of Marksteiner et al. [Phys. Rev. A 53, 3409 (1996)], characterize the transition from normal to anomalous diffusion and the atomic trajectories which give rise to it, and provide a physical explanation for the difference between these two regimes. The full quantum calculations reveal uniquely quantum features of individual atomic trajectories, and in addition, predict significantly lower diffusion, by a factor of 1.2 to 2, than their semiclassical counterparts.