Superfluid to Mott insulator transition in one, two, and three   dimensions
  We have created one-, two-, and three-dimensional quantum gases and study the superfluid to Mott insulator transition. Measurements of the transition using Bragg spectroscopy show that the excitation spectra of the low-dimensional superfluids differ significantly from the three-dimensional case. 
M. K\"ohl, H. Moritz, T. St\"oferle, C. Schori, T. Esslinger