Ak. Yildiz et Jl. Beeby, An investigation of the momentum dependence of the electronic spectrum fora disordered system, PHIL MAG L, 79(3), 1999, pp. 129-136
The spectral properties of disordered systems are investigated using two-di
mensional examples in the tight-binding approximation. The spectra are exam
ined as functions of the momentum wavevector for two-dimensional systems. A
particular example is the directional dependence of the spectrum for a qua
sicrystal, represented by a two-dimensional Penrose lattice. The spectrum c
hanges dramatically, as expected, when the momentum vector moves off a symm
etry axis of the system. The value of this approach for analysing the elect
ronic properties of structurally disordered systems is discussed.