Effects of interaction on the localization of ultracold atoms in a one-dimensional quasi-periodic potential
We study the time evolution of an atomic wave-packet in a 1D quasi-periodic potential by numerically solving a discrete non-linear Schrödinger equation. The results are compared with those obtained for non-interacting particles. In particular we consider the problem of the interplay between Anderson localization and interaction. For the shape of the initial wave-packet we use both a wavefunction completely localized in a single lattice site and a broader wavefunction having Gaussian envelope. In both cases, there are evidences of a destruction of the localization by the interaction between atoms. We discuss also the connection between our results and current experiments with ultracold atoms in bichromatic lattices.