The effects of phason disorder on the dynamical structure factor of Fibonacci 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 phasons can be distinguished for high values of the momentum transfer. However, for both sorts of phasons the response in the acoustic-mode region is quite similar, since the only important quantity is the average length between atoms. In particular, it is shown that a random phason produced in the quasicrystal’s hyperspace leads to a coherent phason field in real space.

• Received 24 September 1998

DOI:https://doi.org/10.1103/PhysRevB.59.14302