Structural and electronic properties of nonperiodic superlattices

A brief review of the structural and electronic properties of Fibonacci, Thue-Morse, and random superlattices (SLs) is given. Quasiperiodic Fibonacci SLs and 1-D analogs of quasicrystals; their wave behavior is characterized by critical hierarchy of gaps. The interest in random SLs focuses on the problem of Anderson localization. Thue-Morse structures are based on an automatic sequence that is not random, periodic, or quasi-periodic. The structural properties of these SLs and results of X-ray and Raman scattering (RS) experiments on GaAs-Al/sub 1-x/Ga/sub x/As and other semiconductor multilayers are discussed.<
>