Structure, Bose-Einstein condensation and superfluidity of   two-dimensional confined dipolar assemblies
  Low temperature properties of harmonically confined two-dimensional assemblies of dipolar bosons are systematically investigated by Monte Carlo simulations. Calculations carried out for different numbers of particles and strengths of the confining potential yield evidence of a quantum phase transition from a superfluid to a crystal-like phase, consistently with what is observed in the ho- mogeneous system. It is found that the crystal phase nucleates in the center of the trap, as the density increases. Bose-Einstein condensation vanishes at T = 0 upon entering the crystalline phase, concurrently with the disappearance of the superfluid response. 
Piyush Jain and Fabio Cinti and Massimo Boninsegni
cond-mat.stat-mech cond-mat.quant-gas