In a recent article [Commun. Theor. Phys. (Beijing, China) 43 (2005) 39], Xie et al. improved the extended tanh function method by introducing a generalized Ric
We investigate the phenomena of symmetry breaking and phase transition in the ground state of BoseEinstein condensates (BECs) trapped in a double square well an
In this paper the macroscopic quantum state of Bose-Einstein condensates in optical lattices is studied by solving the periodic Gross-Pitaevskii equation in one