MAGNETOTUNNELING ANALYSIS OF THE SCATTERING PROCESSES IN A DOUBLE-BARRIER STRUCTURE WITH A 2-DIMENSIONAL EMITTER

We report magnetotunneling results obtained in a high-quality GaAs-Al(x)Ga(1-x)As double-barrier diode with large undoped spacers. Magneto-oscillations of the current in the resonance situation show the two-dimensionality of the source electrons resulting from the formation of an accumulation layer in the emitter. In the off-resonance regime, three different sets of current oscillations have been observed, which correspond to tunneling with elastic- or inelastic-scattering processes on the one hand and to the charge modulation of the accumulation layer on the other hand. From these data the energies of the quantized level in the accumulation layer and in the well are determined as a function of the voltage, in very good agreement with theoretical calculations. Finally, we present theoretical simulations of scattering-assisted magnetotunneling, which account for the experimental data.