  We demonstrate the phenomenon of resonant activation in a non-adiabatically
driven dissipative optical lattice with broken time-symmetry. The resonant
activation results in a resonance as function of the driving frequency in the
current of atoms through the periodic potential. We demonstrate that the
resonance is produced by the interplay between deterministic driving and
fluctuations, and we also show that by changing the frequency of the driving it
is possible to control the direction of the diffusion.
