Weiss oscillations in the presence of small-angle impurity scattering

We calculate the magnetoresistivity of a two-dimensional electron gas in the presence of a periodic potential within classical transport theory, using realistic models of impurity scattering. The magnetooscillations induced by geometric resonance of the cyclotron orbits in the periodic grating, known as Weiss oscillations, are shown to be affected strongly by the small-angle scattering processes dominant in conventional semiconductor heterostructures. Our results are in full agreement with experimental findings.