ELECTRONIC SURFACE-STATES IN SUPERLATTICE WITH COMPLEX BASIS

The electronic structure of a semi-infinite superlattice (SL) with a c omplex basis consisting of two identical wells coupled via two differe nt barriers is investigated. The possibility of the surface state exis tence for a periodic termination of the SL potential (i.e., without pe rturbing the SL potential at the surface) is shown for such a two-barr ier basis, in contrast to the conventional one of single well and barr ier. This main conclusion is based on analytical considerations, howev er, some numerical results for the GaAs/AlAs SL are also presented.