We report on our observation of a structure in the valley region of the current-voltage characteristic of a double-barrier resonant-tunneling structure. We attribute this feature to the LO-phonon-emission-assisted tunneling of electrons from the emitter electrode to the well. In addition, we observe magnetoquantum oscillations in the valley region, which we interpret as due to a momentum-nonconserving component of the tunneling current.

• Received 8 May 1987

DOI:https://doi.org/10.1103/PhysRevB.36.7635