Accumulation of cold cesium molecules via photoassociation in a mixed atomic and molecular trap

We have realized a mixed atomic and molecular trap, constituted by a Cs vapor-cell magneto-optical trap and a quadrupolar magnetic Cs2 trap, using the same magnetic field gradient. We observed the trapping of 2x105 molecules, formed and accumulated in the metastable a 3Σu+ state at a temperature of 30±10 μK through a ≅150 ms photoassociation process. The lifetime of the trapped molecular cloud limited by the Cs background gas pressure is on the order of 1 s