Bloch-like quantum multiple reflections of atoms

We show that under certain circumstances an atom can follow an oscillatory motion in a periodic laser profile with a Gaussian envelope. These oscillat ions can be well explained by using a model of energetically forbidden spat ial regions. The similarities and differences with Bloch oscillations are d iscussed. We demonstrate that the effect exists not only for repulsive but also for attractive potentials, i.e., quantum multiple reflections are also possible. [S1050-2947(99)09408-1].