Achieving very long lifetimes in optical lattices with pulsed cooling

We have realized a one-dimensional optical lattice for individual atoms with a lifetime >300 s, which is 5x longer than previously reported. In order to achieve this long lifetime, it is necessary to laser-cool the atoms briefly every 20 s to overcome heating due to technical fluctuations in the trapping potential. Without cooling, we observe negligible atom loss within the first 20 s followed by an exponential decay with a 62-s time constant. We obtain quantitative agreement with the measured fluctuations of the trapping potential and the corresponding theoretical heating rates.