Soft-core particles freezing to form a quasicrystal and a crystal-liquid phase
journal contributionposted on 2015-09-09, 09:31 authored by Andrew ArcherAndrew Archer, Alastair M. Rucklidge, Edgar Knobloch
Systems of soft-core particles interacting via a two-scale potential are studied. The potential is responsible for peaks in the structure factor of the liquid state at two different but comparable length scales and a similar bimodal structure is evident in the dispersion relation. Dynamical density functional theory in two dimensions is used to identify two unusual states of this system: a crystal-liquid state, in which the majority of the particles are located on lattice sites but a minority remains free and so behaves like a liquid, and a 12-fold quasicrystalline state. Both are present even for deeply quenched liquids and are found in a regime in which the liquid is unstable with respect to modulations on the smaller scale only. As a result, the system initially evolves towards a small-scale crystal state; this state is not a minimum of the free energy, however, and so the system subsequently attempts to reorganize to generate the lower-energy larger-scale crystals. This dynamical process generates a disordered state with quasicrystalline domains and takes place even when this large scale is linearly stable, i.e., it is a nonlinear process. With controlled initial conditions, a perfect quasicrystal can form. The results are corroborated using Brownian dynamics simulations.
The work of E.K. was supported in part by the National Science Foundation under Grant No. DMS-1211953.
- Mathematical Sciences
Published inPHYSICAL REVIEW E
Pages? - ? (14)
CitationARCHER, A.J., RUCKLIDGE, A.M. and KNOBLOCH, E., 2015. Soft-core particles freezing to form a quasicrystal and a crystal-liquid phase. Physical Review E, 92 (1), 012324.
Publisher© American Physical Society
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Publisher statementThis work is made available according to the conditions of the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International (CC BY-NC-ND 4.0) licence. Full details of this licence are available at: https://creativecommons.org/licenses/by-nc-nd/4.0/
NotesThis article was published in the journal, Physical Review E [© American Physical Society]. It is also available at: http://dx.doi.org/10.1103/PhysRevE.92.012324