Accelerated thermalization of 39K atoms in a magnetic trap with superimposed optical potential

We report the rapid accelerated thermalization of potassium (39K) atoms loaded in a magnetic trap, in the presence of a single dipole trap beam. More than an order of magnitude reduction in the thermalization time, to less than a second, is observed with the focused off-resonant beam occupying only 0.01% of the volume of the magnetic trap. A new method for testing for thermalization of relatively hot clouds is devised. The cold atoms are loaded from a magneto-optical trap (MOT) of 39K that has gone through a compressed MOT and sub-Doppler cooling stage. The atoms are prepared in the magnetically stretched |F = 2, mF = 2〉 state prior to loading into the hybrid trap. We also report a direct loading of 39K atoms, prepared in the state |F = 1〉, into a single beam dipole trap. (paper)