Rapid production of 87Rb Bose-Einstein condensates in a combined magnetic and optical potential
We describe an apparatus for quickly and simply producing 87Rb Bose-Einstein condensates. It is based on a magnetic quadrupole trap and a red-detuned optical dipole trap. We collect atoms in a magneto-optical trap (MOT) and then capture the atoms in a magnetic quadrupole trap and force rf evaporation. We then transfer the resulting cold dense cloud into a spatially mode-matched optical dipole trap by lowering the quadrupole field gradient to below gravity. This technique combines the efficient capture of atoms from a MOT into a magnetic trap with the rapid evaporation of optical dipole traps; the approach is insensitive to the peak quadrupole gradient and the precise trapping beam waist. Our system reliably produces a condensate with N≈2×106 atoms every 16 s.