Quantum phase transition of two component dipolar bosons in optical lattices

The energy spectrum of two component Bose-Einstein condensates with the dipole-dipole interaction in optical lattice is obtained by Green function technique. Its superfluid and Mott insulator phase transition is analyzed. The results show that the interspecies hopping and dipole interaction can strongly influence the energy spectrum of two component dipolar bosonic system. A paired atom hopping can exist in superfluid phase while single-atom hopping is Mott insulator, a gapless excite, which is essential to super-counter fluid phase. The special case of phase boundary of super-counter phase are discussed. (c) 2005 Elsevier B.V. All rights reserved.