By recording the fluorescence fraction of the cold atoms remaining in the magneto-optical trap (MOT) as a function of the release time,the release-and-recapture (R&R) method is utilized to evaluate the effective temperature of the cold atomic ensemble.We prepare a single atom in a large-magnetic-gradient MOT and then transfer the trapped single atom into a 1064-nm microscopic optical tweezer.The energy of the single atom trapped in the tweezer is further reduced by polarization gradient cooling (PGC) and the effective temperature is evaluated by extending the R&R technique to a single atom tweezer.The typical effective temperature of a single atom in the tweezer is improved from about 105 μK to about 17 μK by applying the optimum PGC phase.
By recording the fluorescence fraction of the cold atoms remaining in the magneto-optical trap (MOT) as a function of the release time, the release-and-recapture (R&R) method is utilized to evaluate the effective temperature of the cold atomic ensemble. We prepare a single atom in a large-magnetic-gradient MOT and then transfer the trapped single atom into a 1064-nm microscopic optical tweezer. The energy of the single atom trapped in the tweezer is further reduced by polarization gradient cooling (PGC) and the effective temperature is evaluated by extending the R-R technique to a single atom tweezer. The typical effective temperature of a single atom in the tweezer is improved from about 105 μK to about 17 μK by applying the optimum PGC phase.