title: Slow diffusion of light in a cold atomic cloud.
abstract: We study the diffusive propagation of multiply scattered light in an optically thick cloud of cold rubidium atoms illuminated by a quasiresonant laser beam. In the vicinity of a sharp atomic resonance, the energy transport velocity of the scattered light is almost 5 orders of magnitude smaller than the vacuum speed of light, reducing strongly the diffusion constant. We verify the theoretical prediction of a frequency-independent transport time around the resonance. We also observe the effect of the residual velocity of the atoms at long times.
authors.affiliation: Laboratoire Ondes et Désordre, FRE 2302 CNRS, 1361 route des Lucioles, F-06560 Valbonne, France. Guillaume.Labeyrie@inln.cnrs.fr
authors.forename: G
authors.initials: G
authors.lastname: Labeyrie
authors.forename: E
authors.initials: E
authors.lastname: Vaujour
authors.forename: C A
authors.initials: CA
authors.lastname: Müller
authors.forename: D
authors.initials: D
authors.lastname: Delande
authors.forename: C
authors.initials: C
authors.lastname: Miniatura
authors.forename: D
authors.initials: D
authors.lastname: Wilkowski
authors.forename: R
authors.initials: R
authors.lastname: Kaiser