To study ultracold atoms with synthetic vector potentials, we first make Bose-Einstein condensates (BEC) of Rb87 atoms. We capture zeeman-slowed atoms in a Magneto-Optical-Trap, perform polarization gradient cooling, and then load the atoms in a quadrupole magnetic trap with a number of~ 109. After 3.5 s of rf-evaporation, these pre-cooled atoms are transferred into a hybrid potential, a crossed optical dipole trap with a magnetic gradient. After 6 s of evaporative in the dipole trap and a ramp-off of magnetic gradient, we achieved a BEC with 3x105 atoms; the total experimental cycle time is ~ 15 s. We can also load the thermal atoms from the dipole trap into a ring-shaped potential, and produce a BEC with similar atoms to that in the crossed dipole trap.
We then Raman-couple bare spin states of a F=1 BEC with a transfer of orbital-angular-momentum (OAM), where one of the Raman beams is a Laguerre Gaussian beam produced by phase imprinting through a vortex phase plate. We characterize the spin textures and associated gauge potentials in both trap geometries of harmonic potentials (crossed dipole trap) and ring-shaped potentials.
We then Raman-couple bare spin states of a F=1 BEC with a transfer of orbital-angular-momentum (OAM), where one of the Raman beams is a Laguerre Gaussian beam produced by phase imprinting through a vortex phase plate. We characterize the spin textures and associated gauge potentials in both trap geometries of harmonic potentials (crossed dipole trap) and ring-shaped potentials.