title: Decoherence and disorder in quantum walks: from ballistic spread to localization.
abstract: We investigate the impact of decoherence and static disorder on the dynamics of quantum particles moving in a periodic lattice. Our experiment relies on the photonic implementation of a one-dimensional quantum walk. The pure quantum evolution is characterized by a ballistic spread of a photon's wave packet along 28 steps. By applying controlled time-dependent operations we simulate three different environmental influences on the system, resulting in a fast ballistic spread, a diffusive classical walk, and the first Anderson localization in a discrete quantum walk architecture.
authors.affiliation: Max Planck Institute for the Science of Light, Erlangen, Germany. Andreas.Schreiber@mpl.mpg.de
authors.forename: A
authors.initials: A
authors.lastname: Schreiber
authors.forename: K N
authors.initials: KN
authors.lastname: Cassemiro
authors.forename: V
authors.initials: V
authors.lastname: Potoček
authors.forename: A
authors.initials: A
authors.lastname: Gábris
authors.forename: I
authors.initials: I
authors.lastname: Jex
authors.forename: Ch
authors.initials: Ch
authors.lastname: Silberhorn