Quantum phase transition of condensed bosons in optical lattices
J.-Q. Liang, J.-Q. Liang, W.M. Liu
In this paper we study the superfluid--Mott-insulator phase transition of ultracold dilute gas of bosonic atoms in an optical lattice by means of Green function method and Bogliubov transformation as well. The superfluid--Mott-insulator phase transition condition is determined by the energy-band structure with an obvious interpretation of the transition mechanism. Moreover the superfluid phase is explained explicitly from the energy spectrum derived in terms of Bogliubov approach.
arXiv:cond-mat/0403571•Physical Review A•Oct 8, 2003•45 citations