GAAS-ALGAS superlattice band structure under hydrostatic pressure: An analysis based on the envelope function approximation

We propose new interface connection rules to determine the electronic properties of superlattices. Although similar to the so-called two-band model, these new rules are more general. Our approach is used to study the electronic structure of superlattices under high hydrostatic pressure. In our model, the influence of the pressure is taken into account by considering the modification of the energy gap and layer width of each material separately. It is demonstrated that the low value observed in the experimental determination of the pressure coefficient θ^SL of the GaAs layers is a consequence of the increasing rigidity of the energy band for energies away from the edges. Moreover the apparent homogeneity of θ^SL (GaAs) is the result of two opposing effects-the variation of the band rigidity and the narrowing of the layer thickness-which compensate each other.