Absolute negative conductivity and spontaneous current generation in semiconductor superlattices with hot electrons

We study transport through a semiconductor superlattice with an electric fi eld parallel to and a magnetic field perpendicular to the growth axis. Usin g a semiclassical balance equation model with elastic and inelastic scatter ing, we find that (1) the current-voltage characteristic becomes multistabl e in a large magnetic field and (2) "hot" electrons display novel features in their current-voltage characteristics, including absolute negative condu ctivity and a spontaneous de current at zero bias. We discuss experimental situations providing hot electrons to observe these effects.