title: Observation of subdiffusion in a disordered interacting system.
abstract: We study the transport dynamics of matter-waves in the presence of disorder and nonlinearity. An atomic Bose-Einstein condensate that is localized in a quasiperiodic lattice in the absence of atom-atom interaction shows instead a slow expansion with a subdiffusive behavior when a controlled repulsive interaction is added. The measured features of the subdiffusion are compared to numerical simulations and a heuristic model. The observations confirm the nature of subdiffusion as interaction-assisted hopping between localized states and highlight a role of the spatial correlation of the disorder.
authors.affiliation: LENS and Dipartimento di Fisica e Astronomia, Università di Firenze, and INO-CNR, Sesto Fiorentino, Italy. lucioni@lens.unifi.it
authors.forename: E
authors.initials: E
authors.lastname: Lucioni
authors.forename: B
authors.initials: B
authors.lastname: Deissler
authors.forename: L
authors.initials: L
authors.lastname: Tanzi
authors.forename: G
authors.initials: G
authors.lastname: Roati
authors.forename: M
authors.initials: M
authors.lastname: Zaccanti
authors.forename: M
authors.initials: M
authors.lastname: Modugno
authors.forename: M
authors.initials: M
authors.lastname: Larcher
authors.forename: F
authors.initials: F
authors.lastname: Dalfovo
authors.forename: M
authors.initials: M
authors.lastname: Inguscio
authors.forename: G
authors.initials: G
authors.lastname: Modugno