Hole subband non-parabolicities in strained Si/Si1-xGex quantum wells

We study the hole subband non-parabolicities in undoped pseudomorphic Si/Si 1-xGex quantum wells, strained in the growth direction [100]. We solve exac tly the multiband effective mass equation that describes the heavy, light a nd split-off hole valence bands. The symmetries of the Luttinger-Kohn Hamil tonian of the system are used to decouple the degenerate subbands. We calcu late the in-plane dispersion relations, investigate the importance of the i nclusion of the split-off hole valence band in the Hamiltonian and comment on the resulted non-parabolicities. Resonance states are also obtained. (C) 1998 Academic Press.