Magnetotransport in lateral superlattices with small-angle impurity scattering: Low-field magnetoresistance - art. no. 125319

An analytical study of the low-field magnetoresistance of a two-dimensional electron gas subject to a weak periodic modulation is presented. We assume the small-angle impurity scattering characteristic for high-mobility semic onductor heterostructures. It is shown that the condition for existence of the strong low-field magnetoresistance induced by so-called channeled orbit s is eta (3/2)ql much greater than 1, where eta and q are the strength and the wave vector of the modulation, and l is the transport mean free path. U nder this condition, the amplitude of the magnetoresistance Delta rho/rho s cales as eta (7/2)(ql)(2), while the modulation-induced correction to resis tivity at zero magnetic field is of the order of eta (1/2).