Airy-coordinate Green's-function technique for high-field transport in semiconductors

We introduce an Airy-coordinate formulation of the Kadanoff-Baym-Keldysh Green's-function techniques to treat electron-phonon coupling in a high electric field. The resulting Dyson's equation is simpler than those found in purely momentum-coordinate formulations, and suggests a natural approximation. We observe oscillations due to phonon coupling which are incommensurate with those due to standing waves in the unperturbed problem.