A second generation Cs BEC experiment

Full text: We present the status of a new Cs BEC experiment aiming to use a BEC as a source for precision measurements. An all-optical BEC will be produced in a glass cell apparatus, representing a major improvement compared to our first Cs BEC experiment, because it allows maximum optical access and faster switching of magnetic fields. A high loading rate and a large-volume optical dipole trap at near infrared wavelengths together with optimized 3D Raman sideband cooling should allow for large Cs condensates with more than 106 atoms. The s-wave interactions tunable through Feshbach resonances at low magnetic fields enable us to study the regime of zero scattering length. A BEC without perturbing mean-field shifts is ideally suited for atom interferometry in precision measurements. As an example, it is possible to determine the fine structure constant via a measurement of the photon recoil in an atom interferometer. We report on the status of loading the Cs BEC into a 3D optical lattice. Combined with the tunable interactions, this is a convenient environment for the detailed exploration of weakly and strongly interacting atoms, the study of collisions and the formation of a molecular BEC starting from a Mott insulator state. Refs. 4 (author)