THEORY OF INTERBAND TUNNELING IN CRYSTALS WITH PHONONS

A general theory is presented for the interband tunnelling probability of electrons in a crystal in the presence of phonons and a strong electric field, for both the phonon-assisted and the phonon-modified-Zener tunnelling. For the case of tunnelling from a fully occupied band the dependence of the tunnelling rate on the electric field is shown in both cases to exhibit a steady term and some oscillatory terms. Similar oscillatory behaviour has been measured recently in semiconducting superlattices.