Feshbach resonances in mixtures of ultracold Li-6 and Rb-87 gases

We report on the observation of two Feshbach resonances in collisions between ultracold Li-6 and Rb-87 atoms in their respective hyperfine ground states vertical bar F,m(F)>=vertical bar 1/2,1/2 > and vertical bar 1,1 >. The resonances show up as trap losses for the Li-6 cloud induced by inelastic Li-Rb-Rb three-body collisions. The magnetic field values where they occur represent important benchmarks for an accurate determination of the interspecies interaction potentials. A broad Feshbach resonance located at 1066.92 G opens interesting prospects for the creation of ultracold heteronuclear molecules. We furthermore observe a strong enhancement of the narrow p-wave Feshbach resonance in collisions of Li-6 atoms at 158.55 G in the presence of a dense Rb-87 cloud. The effect of the Rb-87 cloud is to introduce Li-Li-Rb three-body collisions occurring at a higher rate than Li-Li-Li collisions.