Feshbach resonances in an ultracold mixture of 87Rb and 40K

Abstract

We report the experimental preparations of the absolute ground states of 87Rb and 40K atoms (|F = 1, mF = 1〉 + |F = 9/2, mF = −9/2〉) by means of the radio-frequency and microwave adiabatic rapid passages, and the observation of magnetic Feshbach resonances in an ultracold mixture of bosonic 87Rb and fermionic 40K atoms between 0 T and 6.0 × 10−2 T, including 7 homonuclear and 4 heteronuclear Feshbach resonances. The resonances are identified by the abrupt trap loss of atoms induced by the strong inelastic three-body collisions. These Feshbach resonances should enable the experimental control of interspecies interactions.