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 inte raction. In addition to characterizing the momentum and position distr ibutions, we show that resonant tunnelling between adjacent optical po tential wells leads to a sizable variation of the lowest-energy state population, as a function of the field parameters.