Mixed-isotope Bose-Einstein condensates in rubidium

0The ground-state properties of mixed-isotpe Bose-Einstein condensates (BEC) in 87Rubidium (Rb) and 85Rb atoms were discussed. It was observed that the overlapping condensates of 87Rb in the spin states were produced by lossless sympathetic cooling of the atoms by thermal contact with the atoms. It was observed that the threshold for the symmetry-breaking transition of the repulsive species interaction was related to appearance of a zero dipole mode. It was observed that the condensation of 85Rb and 87Rb atoms through sympathetic cooling exhibited low inelastic collision rates.