A perturbative approach to the spectral properties of a quasi-crystalline chain

Abstract
The vibrational and electronic properties of a one-dimensional quasi-crystal are analysed. The spectra are seen to be Cantor-like sets. Expressions are obtained for the positions and magnitude of the band gaps, the densities of states and the fractal dimensions of the excitation spectra. These are shown to be in good agreement with the numerical results in the range of validity of the analytic results.