1. Extend the previous exercise to estimate the position and width of the lowest band in a superlattice of alternating 5 nm wells and 5 nm barriers of height 0.3 eV in GaAs. A numerical calculation puts the edges of the bands at -0.215 eV and -0.205 eV, measured from the tops of the barriers.
2. Calculate the effective mass near a band gap from equation (7.113). How are the mass and gap related, and do these results agree with the predictions of the k p method?
