Scattering of holes by the GaAs/AlAs (111) and (110) interfaces.

The 18-band kp model is used to analyze the wave functions of the states in the valence band. It is found that the typically used approximation based on the assumption that the effective masses are energy-independent for the band of light and heavy holes is justified only near the valence-band top. The conditions for matching of the envelope functions for holes at the GaAs/AlAs heterointerfaces with the (111) and (110) orientations taking into account and disregarding the spin-orbit interaction for energies in the vicinity of the valence-band top are considered. These conditions are derived as a result of simplifying the description of electronic states using the pseudopotential method. The matching conditions obtained are completely consistent with the problem’s symmetry. These conditions involve mixing of the envelope functions with their normal derivatives and mixing of derivatives with the functions. It is shown that the light and heavy holes are not mixed at the (111) heterointerface but are mixed at the (110) heterointerface. It is found that the states are mixed at resonance energies to a much greater extent at the (110) heterointerface than at the (001) interface. [ABSTRACT FROM AUTHOR]