Bose-Einstein Condensates in Rotating Lattices
  Strongly interacting bosons in 2D in a rotating square lattice are investigated via a modified Bose-Hubbard Hamiltonian. Such a system corresponds to a rotating lattice potential imprinted on a trapped Bose-Einstein condensate. Second-order quantum phase transitions between states of different symmetries are observed at discrete rotation rates. For the square lattice we study, there are four possible ground-state symmetries. 
Rajiv Bhat (1), L. D. Carr (2), M. J. Holland (1) ((1) JILA, National   Institute of Standards and Technology and Department...