Magnetic control of the interaction in ultracold K-Rb mixtures

We predict the presence of several magnetic Feshbach resonances in selected Zeeman sublevels of K-40-Rb-87 and K-41-Rb-87 at magnetic fields up to 10(3) G. Positions and widths are determined combining a new measurement of the K-40-Rb-87 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 K-40-Rb-87 atomic gas and for the production of ultracold polar molecules.