Bose-Einstein condensation thermodynamics of a trapped gas with attractiveinteraction

We study the Bose-Einstein condensation of an interacting gas with attracti ve interaction confined in a harmonic trap using a semiclassical two-fluid mean-field model. The condensed state is described by the converged numeric al solution of the Gross-Pitaevskii equation. By solving the system of coup led equations of this model iteratively we obtain the converged results for the temperature dependencies of the condensate fraction, chemical potentia l, and internal energy for the Bose-Einstein condensate of Li-7 atoms. (C) 2000 Elsevier Science B.V. All rights reserved.