Quantum phase transitions and coherent tunneling in a bilayer of ultracold atoms with dipole interactionsA.C. Ji, Q. Sun, X.H. Hu, W.M. Liu and X.C. XieEur. Phys. J. B, 85 6 (2012) 194DOI: https://doi.org/10.1140/epjb/e2012-30151-x