COOLING AND TUNNELING OF ATOMS IN A 2D LASER FIELD

We present a quantum treatment of Sisyphus cooling in two dimensions. The steady state is given by the populations of the energy eigenstates for the atomic motion in the potential created by the atom-light interaction. In addition to characterizing the momentum and position distributions, we show that resonant tunnelling between adjacent optical potential wells leads to a sizable variation of the lowest-energy state population, as a function of the field parameters.