Magnetic Control of the Interaction in Ultracold K-Rb Mixtures

Abstract

We predict the presence of several magnetic Feshbach resonances in selected Zeeman sublevels of the isotopic pairs $^{40}\mathrm{K}\mathrm{\text{\ensuremath{-}}}^{87}\mathrm{R}\mathrm{b}$ and $^{41}\mathrm{K}\mathrm{\text{\ensuremath{-}}}^{87}\mathrm{R}\mathrm{b}$ at magnetic fields up to ${10}^{3}\text{ }\mathrm{G}$. Positions and widths are determined combining a new measurement of the $^{40}\mathrm{K}\mathrm{\text{\ensuremath{-}}}^{87}\mathrm{R}\mathrm{b}$ inelastic cross section with recent experimental results on both isotopes. The possibility of driving a K-Rb mixture from the weak to the strong interacting regime tuning the applied field should allow one to achieve the optimal conditions for boson-induced Cooper pairing in a multicomponent $^{40}\mathrm{K}\mathrm{\text{\ensuremath{-}}}^{87}\mathrm{R}\mathrm{b}$ atomic gas and for the production of ultracold polar molecules.