PROPERTIES OF 2-SPECIES BOSE CONDENSATES

We present theoretical studies of a two-species Bose condensate. Using a new numerical method, we have calculated ground state wave function s and show that, due to interspecies interactions, the condensate mixt ure displays novel behavior not found in a pure condensate. We compare d our results with those of the Thomas-Fermi approximation (TFA) and f ind that under a broad range of conditions the TFA can be reliably use d to predict many qualitative features of the condensates, Using our t echnique, we have modeled a recent JILA experiment on dual spin-state Rb-87 condensate. Finally, collective excitations of double condensate s are discussed. [S0031-9007(97)05211-3].