(color online) Loading time as a function of the ultra-violet light intensity and spatial distribution of traps. (a) The black squares show dependence of the loading time of obtained one atom on ultra-violet light intensity. The loading time decreases to ∼ 100 ms which is in practice limited by sizes of two traps with a contrast of ∼ 3 orders of magnitude. (b) The red points show the dependence of the loading time of obtained one atom on displacements between the trap centers, where the time is dominated by spatial probability distribution of single atom in MOT. The blue solid circles show a decrease of the loading time to a constant offset for a large range of spatial distribution of traps intensities by employing feedback control. Error bars represent the statistic results.