3-DIMENSIONAL BOLTZMANN-BLOCH THEORY OF MINIBAND TRANSPORT IN SUPERLATTICES WITH ELASTIC-SCATTERING

Elastic scattering couples the quasi one-dimensional (1D) motion of el ectrons responding to an applied electic field in growth direction of a semiconductor superlattice effectivelly to the lateral degrees of fr eedom. We describe the superlattice by a simple miniband and elastic s cattering explicitly by an appropriate collision term in Boltzmann's e quation. As a function of the applied field, we calculate the heating of the electron system and its drift velocity, which shows pronounced negative differential conductance. Our results are qualitatively diffe rent from those of previous 1D theories, but compare favorably with re sults of recent experiments and balance-equation calculations.