Abstract
In order to study heterostructures composed both of materials with strongly different parameters and of materials with narrow band gaps, we have developed an approach [E. P. Pokatilov et al., Phys. Rev. B 64, 245328 (2001), preceding paper)], which combines the spherical eight-band effective-mass Hamiltonian and the Burt’s envelope-function representation. Using this method, electron and hole states are calculated in and quantum dot quantum-well heterostructures. Radial components of the wave functions of the lowest S and P electron and hole states in typical quantum dot quantum wells (QDQW’s) are presented as a function of radius. The six-band-hole components of the radial wave functions of an electron in the eight-band model have amplitudes comparable with the amplitude of the corresponding two-band-electron component. This is a consequence of the coupling between the conduction and valence bands, which gives a strong nonparabolicity of the conduction band. At the same time, the two-band-electron component of the radial wave functions of a hole in the eight-band model is small compared with the amplitudes of the corresponding six-band-hole components. It is shown that in the holes in the lowest states are strongly localized in the well region (HgS). On the contrary, electrons in this QDQW and both electron and holes in the are distributed through the entire dot. The importance of the developed theory for QDQW’s is proven by the fact that in contrast to our rigorous eight-band model, there appear spurious states within the commonly used symmetrized eight-band model.
- Received 12 April 2001
DOI:https://doi.org/10.1103/PhysRevB.64.245329
©2001 American Physical Society