Magnetic-field-induced recovery of resonant tunneling into a disordered quantum well subband

We investigate how the disorder produced by a layer of self-assembled InAs quantum dots affects the electronic states of a GaAs quantum well incorporated in a double barrier resonant tunneling diode. The disorder strongly suppresses the resonant peak in the current due to electron tunneling into the lowest energy subband of the quantum well. However, the peak is recovered by the application of an in-plane magnetic field, which provides a means of tuning the in-plane momentum of the tunneling electrons. Analysis of these data and of Landau level formation when the field is applied perpendicular to the quantum well plane provides information about the length-scale of disorder potential in the well.