Ultracold scattering properties of the short-lived Rb isotopes

We compute the scattering properties of rubidium atoms at ultracold temperatures, placing special emphasis on the radioactive isotopes Rb-82,Rb-83,Rb-84, and Rb-86. In combination with the more "conventional" isotope Rb-87, these species yield a wide variety of scattering behavior, with consequences for creating mixtures of Fermi-Fermi, Fermi-Bose, and Bose-Bose gases. In each of these mixtures we find at least one case where the interspecies scattering lengths can be tuned using an external magnetic field. These results should greatly broaden the prospects for quantum degenerate gases in future experiments. [S1050-2947(99)06802-X].