Influence of narrow inner barriers on the low-temperature lateral conduction in quantum wells

Abstract

The electron energy spectrum of a wide quantum well with a different number of narrow barriers inside the well region was calculated. It was shown that the size-quantization levels rise in energy upon the introduction of such barriers. When the maximum filling of the quantum well with narrow barriers was reached and the fragment of a short-period superlattice was formed, the envelopes of the electron wave functions on the size-quantization levels were similar in shape to those in a usual quantum well. In this case, the scattering by the surface roughness of the heterojunctions was significantly increased. The low-temperature lateral conduction in a quantum well tunnel-coupled with a 10-well short-period superlattice and, separately, in the superlattice alone was investigated experimentally. The obtained results agreed sufficiently well with the model calculations and demonstrated a new way to form parallel conducting channels with different electron mobility.