Magnetic trapping of a cold Rb-Cs atomic mixture

We present an apparatus for the study of an ultracold gaseous atomic mixture of Cs and Rb. The mixture is prepared using a double magneto-optical trap (MOT) system in which a two-species pyramid MOT acts as a source of cold atoms for a ‘science’ MOT. Measurements of the interspecies trap loss rate coefficients βRbCs and βCsRb in the science MOT are reported. After the initial MOT phase, atoms in the mixture are optically pumped into the magnetically trappable |F =3,mF =−3〉 and |F =1,mF =−1〉 states of Cs and Rb (respectively) and loaded into an Ioffe-Pritchard magnetic trap. We demonstrate a novel technique for limiting the interspecies loss rate in the science MOT by spatially separating the two trapped atom clouds, which greatly enhances the number of atoms which can be loaded into the magnetic trap. E-mail: [email protected] PACS numbers: 32.80.Pj, 34.50.Rk, 37.20.Tj, 37.10.Gh, 37.10.Vz Magnetic trapping of a cold Rb-Cs atomic mixture 2