View article

We construct a compact experimental apparatus for producing high-repetition-rate ultra cold ⁸⁷Rb atom based on an external atom chip. Initially, we produce an atomic flux from a 2D⁺ MOT (magneto-optical trap) in a nearly isolated 2D⁺ MOT chamber and improve the flux by adjusting the cooling beam detuning of the 2D⁺ MOT. The flux is trapped in the 3D MOT for 1.2 s and is further cooled by performing compressing the MOT for 20 ms and using polarization gradient cooling for 6.2 ms. After optical pumping into the 5S F = 2 (m _F = 2) ground state, we transport atoms toward the chip surface by performing external Z coil trapping. At 1 mm below the chip surface, the external Z coil trap is completely switched to an atom chip trap by using a Z wire and a dimple wire on the chip with external bias fields. The transport and the switching take totally 520 ms. The number of atoms …