Ultracold collisions involving heteronuclear alkali metal dimers -: art. no. 200402

We carry out the first quantum dynamics calculations on ultracold atom-diatom collisions in isotopic mixtures. The systems studied are spin-polarized Li-7+(LiLi)-Li-6-Li-7, Li-7+Li-6(2), Li-6+(LiLi)-Li-6-Li-7, and Li-6+Li-7(2). Reactive scattering can occur for the first two systems even when the molecules are in their ground rovibrational states, but is slower than vibrational relaxation in homonuclear systems. Implications for sympathetic cooling of heteronuclear molecules are discussed.