WAVE-FUNCTION ENGINEERING IN ASYMMETRIC MODULATION-DOPED QUANTUM-WELLS

We present self-consistent calculations for asymmetric modulation-doped quantum wells. For n-type quantum wells we display wave-functions, potential and energy sublevels as the asymmetry of the quantum wells is gradually increased. For a small but finite asymmetry the wavefunctions of the lowest two subbands become "polarized", i.e. concentrated to one of the two interface regions. A very large asymmetry is needed to localize all the electrons to one of the interface regions. The wavefunctions at k∥ = 0 are changed in a similar way for p-type quantum wells, but here additional interesting features are obtained. The subband structure becomes very complicated because of the combination of spin-orbit interaction and inversion asymmetry. For some subbands the localization of the holes is found to change rapidly with the wave vector parallel to the interfaces. © 1990.