Growth of entropy stabilized quasicrystals

Abstract:

A simplified version of the model by Elser and Joseph for the process of growth of an entropically stabilized, two-dimensional quasicrystal with no dynamics in the bulk, is proposed. The phason fluctuations are modeled by a scalar field on a periodic lattice. The choice of the master equation for the growth is restricted by the requirement that its detailed balance solution describes the equilibrium fluctuations of the field with a quadratic Hamiltonian. The model is parametrized by the chemical potential bias and the microscopic surface tension coefficient . The phase diagram of the system on the plane (, ) shows several distinct regimes of growth, separated by relatively narrow transition zones. Within the regions corresponding to these regimes, the phason fluctuations do not depend on and . Analytic expressions for the spectra of phason fluctuations are obtained and confirmed by numerical simulation.