Lateral resonant tunneling through constrictions in a δ -doped GaAs layer

Abstract

We have fabricated constrictions in δ-doped GaAs using implanted gates to provide the lateral confinement. Large conductance oscillations are observed when the gate voltage is varied. The drain-source current-voltage characteristics are highly nonlinear; as many as 30 peaks are present, and peak-to-valley ratios greater than 100 have been measured. These results are explained in terms of resonant tunneling through the random potential distribution in the point contact. Using a simple model for the potential distribution we are able to simulate qualitatively the structure in the conductance.