On the basis of Boltzmann's equation, and including anisotropic scattering in
the collision operator, we investigate the effect of one-dimensional
superlattices on two-dimensional electron systems. In addition to superlattices
defined by static electric and magnetic fields, we consider mobility
superlattices describing a spatially modulated density of scattering centers.
We prove that magnetic and electric superlattices in x-direction affect only
the resistivity component ρxx if the mobility is homogeneous, whereas a
mobility lattice in x-direction in the absence of electric and magnetic
modulations affects only ρyy. Solving Boltzmann's equation numerically,
we calculate the positive magnetoresistance in weak magnetic fields and the
Weiss oscillations in stronger fields within a unified approach.Comment: submitted to PR