Density of electronic states in a biased resonant tunneling structure

Abstract
We calculate the change in the density of states due to a biased resonant tunneling structure. The maximum of the density of states near resonance gets shifted towards the low-energy side compared to the unbiased case, as does the transmission coefficient, although the two need not be identical. For the case of asymmetric barrier heights, the left-right symmetry of the density of states is broken when the field is nonvanishing.