Key points are not available for this paper at this time.
Boltzmann's equation is solved for electrons in a one-dimensional superlattice under the influence of a uniform electric field; an energy independent scattering time and nonspherical energy bands are assumed. The current density-electric field characteristic shows negative differential conductivity at fields of 103−104 V/cm independent of the detailed shape of the minibands.
Lebwohl et al. (Fri,) studied this question.