Coherency of phason dynamics in Fibonacci chains

The effects of phason disorder on the dynamical structure factor of Fibonac ci chains are studied, and the existence of a coherent phason field in real quasicrystals is addressed. The neutron-scattering response is modeled for coherent and random phasons. The results show that coherent and random pha sons con be distinguished for high values of the momentum transfer. However , for both sorts of phasons the response in the acoustic-mode region is qui te similar, since the only important quantity is the average length between atoms. In particular, it is shown that a random phason produced in thr qua sicrystal's hyperspace leads to a coherent phason field in real space.