Electronic structure and localization behaviour in the GaAs/AlAs Fibonacci superlattice

We study the electronic structure of the GaAs/AlAs Fibonacci superlattice using a semi-empirical sp3s* tight-binding method. We find that a self-similar energy spectrum can be seen in the band structure, although the energy spectrum depends strongly on the wavevector parallel to the layers. Furthermore, we find that a localization character is enhanced due to the band hybridization, producing a spiky density of states and a localization-like effect of the wavefunctions in the hybridized energy region. The reasons for the localization-like behaviour are discussed briefly.