SEMICLASSICAL MAGNETOTRANSPORT THEORY FOR 2-DIMENSIONAL ELECTRON-SYSTEMS IN LATERAL SUPERLATTICES

Based on the correct single-electron energy spectra we calculate, with in a semiclassical approach, the conductivity of periodically modulate d two-dimensional electron systems in a perpendicular magnetic field B . For B = O we obtain, as a function of the Fermi energy, fluctuations of the conductivity, which result from the energy gaps in a perfectly periodic modulation potential, but may easily be smeared out by disor der. Introducing a smooth interpolation between the energy bands in th e extended zone scheme and taking magnetic breakdown effects properly into account, we calculate the magnetoresistance for a strong unidirec tional modulation and magnetic fields of arbitrary strengths, neglecti ng these quantum fluctuations.