LINEAR K-TERM VALENCE SUBBAND MIXING AND ITS EFFECT ON ELECTROABSORPTION OF TENSILE-STRAINED GAAS ALGAAS QUANTUM-WELLS/

We have examined the contribution of a linear k term in the Luttinger Hamiltonian to electroabsorption of strained quantum wells. We have so lved the 4 x 4 effective mass equation for the two lowest valence subb ands and an appropriate set of differential equations for excitons. Fo r bound excitons, our results indicate that the hh1 --> c1 transition is not forbidden for z-polarized electromagnetic waves, that the absor ption spectrum can be independent of polarization, and that the hh1 an d lh1 absorption edges, contrary to recent suggestion, cannot merge.