Phonon-assisted resonant-magneto-tunneling in double barrier heterostructures

Abstract

Phonon-assisted resonant magneto-tunneling has been considered within the coherent tunneling model. The magneto-tunneling case is particularly interesting because the effective electron-phonon coupling increases with the increasing magnetic field as geff ∝ Bη, where η = 1/2 for the LO-phonon coupling and 1 < η < 3/2 in the case of deformational acoustical phonons. Under the magneto-LO-phonon resonance condition, the mixing of tunneling channels leads in the case of phonon emission to a sharp splitting of the transmission peak, the splitting beeing proportional to geff. A smooth smearing of the peak is on the contrary seen in the case of incoherent phonon absorption processes. For the acoustical deformational interaction, we focus on the coupling to non-equilibrium phonons. It is shown that dc-current profile is very sensitive to the presence of non-equilibrium phonons, as well as to their frequency distribution. In particular, we believe that the resonant magneto-tunneling device can be useful for detection and spectroscopy of the phonons and electron-phonon interactions.