Binary mixtures of condensates in generic confining potentials

We study a binary mixture of BoseEinstein condensates, confined in a generic potential, in the ThomasFermi approximation. We search for the zero-temperature ground state of the system, both in the case of fixed numbers of particles and fixed chemical potentials. For generic potentials, we analyze the transition from mixed to separated ground-state configurations as the inter-species interaction increases. We derive a simple formula that enables one to determine the location of the domain walls. Finally, we find criteria for the energetic stability of separated configurations, depending on the number and the position of the domain walls separating the two species. © 2011 IOP Publishing Ltd.