Evanescent channels in calculation of phonon-assisted tunneling spectrum of a semiconductor tunneling structure

Abstract

The one‐dimensional electron resonant tunneling spectrum is calculated for a GaAs/AlGaAs double barrier resonant tunneling structure in the presence of electron‐optical‐phonon scattering using a model similar to the independent‐boson model. The calculation scheme developed by Cai et al. [Phys. Rev. Lett. 63, 418 (1989)] is examined in the situation when the electronic evanescent state is involved. Via the electron‐phonon interaction, the coupling between an unbounded electronic state and an evanescent state is studied and found to be weakened. The calculated tunneling spectrum shows the one‐phonon emission sideband as indicated in the experimental data [V. J. Goldman, D. C. Tsui, and J. E. Cunningham, Phys. Rev. B 36, 7635 (1987)] and in another theoretical calculation [N. S. Wingreen, K. W. Jacobsen, and J. W. Wilkins, Phys. Rev. Lett. 61, 1396 (1988)].