Effect of optical disorder and single defects on the expansion of a   Bose-Einstein condensate in a one-dimensional waveguide
  We investigate the one-dimensional expansion of a Bose-Einstein condensate in an optical guide in the presence of a random potential created with optical speckles. With the speckle the expansion of the condensate is strongly inhibited. A detailed investigation has been carried out varying the experimental conditions and checking the expansion when a single optical defect is present. The experimental results are in good agreement with numerical calculations based on the Gross-Pitaevskii equation. 
C. Fort, L. Fallani, V. Guarrera, J. Lye, M. Modugno, D. S. Wiersma,   M. Inguscio