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

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.