Collisional losses in a K-Rb cold mixture

Abstract

We have observed a heteronuclear trap loss rate for a mixture of trapped ${}^{39}\mathrm{K}$ and ${}^{85}\mathrm{Rb}$ atoms. Our results indicate that hyperfine changing collision and radiative escape dominate in the low and high intensity regimes, respectively. They are also consistent with radiative escape taking place with the participation of the doubly excited state potential $({\mathrm{K}}^{*}\ensuremath{-}{\mathrm{Rb}}^{*}).$ A Gallagher-Pritchard model taking into account the doubly excited channel was implemented, reproducing the experimental results well qualitatively. The values obtained for the cross species trap loss indicate possibilities of future experiments with this mixture.