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CPP: Fachverband Chemische Physik und Polymerphysik

CPP 43: Droplets, Wetting, Complex Fluids, and Soft Matter (joint session DY/CPP)

CPP 43.9: Vortrag

Freitag, 21. März 2025, 12:00–12:15, H47

Cluster quasicrystals composed of ultrasoft particles vs. soft quasicrystals built of colloids with hard cores — Robert F.B. Weigel and •Michael Schmiedeberg — Theoretical Physics: Lab for Emergent Phenomena, Friedrich-Alexander-Universität Erlangen-Nürnberg, 91058 Erlangen, Germany

We study and compare two different approaches for the stabilization of quasicrystals:

First, we consider a Phase Field Crystal model of complex patterns that self-assemble in systems consisting of ultrasoft colloids. Quasicrystals can be either stabilized by interactions with multiple length scales [1,2] or by preferred binding angles as in patchy colloids [3].

Second, we study a system with patchy colloids with a hard core with a Density Functional Theory. The hard-core is implemented by using a variant of the Fundamental Meassure Theory [4] that probably is the best mean field approach to hard particles.

While the ultrasoft particles assemble in cluster quasicrystals where the particles can completely overlap, in case of hard cores we observe structures that are rather dominated by the tiles that occur on a local level. Our results explain the differences between quasicrystlas that occur in different systems.

[1] Lifshitz, Petrich, PRL 79, 1261 (1997).

[2] Achim et al., PRL 112, 255501 (2014).

[3] Weigel, Schmiedeberg, Modelling Simul. Mater. Sci. Eng. 30, 074003 (2022).

[4] Rosenfeld, PRL 63, 980 (1989).

Keywords: Colloids; Patchy Particles; Quasicrystals; Classical Density Functional Theory; Phase Field Crystal Model