Interacting bosons beyond the Gross-Pitaevskii mean field

Systems consisting of cold interacting bosons show interesting collective phenomena such as Bose-Einstein condensation or superfluidity and are currently studied in condensed matter and atomic physics. Of particular interest are nonideal bosons which exhibit strong correlation and spatial localisation effects. Here we analyse the ground-state of a two-dimensional Bose system with a Hartree-Fock type approximation that was first introduced by Romanovsky et al. [Phys. Rev. Lett. 93 (2004) 230405]. We apply this method to a one-dimensional system of charged bosons and analyse the behaviour at strong coupling.