One-dimensional phase transitions in a two-dimensional optical lattice
  A phase transition for bosonic atoms in a two-dimensional anisotropic optical lattice is considered. If the tunnelling rates in two directions are different, the system can undergo a transition between a two-dimensional superfluid and a one-dimensional Mott insulating array of strongly coupled tubes. The connection to other lattice models is exploited in order to better understand the phase transition. Critical properties are obtained using quantum Monte Carlo calculations. These critical properties are related to correlation properties of the bosons and a criterion for commensurate filling is established. 
Magnus Rehn, Sara Bergkvist, Anders Rosengren, Robert Saers, Martin   Zel\'an, Emil Lundh, Anders Kastberg