Quasicrystal formation in binary soft matter mixtures

TL;DR

This paper identifies conditions for quasicrystal formation in binary soft matter mixtures using density functional and integral equation theories, focusing on tuning lengthscale ratios via interaction ranges.

Contribution

It introduces a method to predict quasicrystal formation in mixtures by analyzing dispersion relations and structure factors, extending understanding beyond single-component systems.

Findings

Quasicrystals form when two characteristic lengthscales are in specific ratios.

Tuning interaction ranges influences the emergence of quasicrystals.

The approach applies to both theoretical models and experimental systems.

Abstract

Using a strategy that may be applied in theory or in experiments, we identify the regime in which a model binary soft matter mixture forms quasicrystals. The system is described using classical density functional theory combined with integral equation theory. Quasicrystal formation requires particle ordering with two characteristic lengthscales in certain particular ratios. How the lengthscales are related to the form of the pair interactions is reasonably well understood for one component systems, but less is known for mixtures. In our model mixture of big and small colloids confined to an interface, the two lengthscales stem from the range of the interactions between pairs of big particles and from the cross big-small interactions, respectively. The small-small lengthscale is not significant. Our strategy for finding quasicrystals involves tuning locations of maxima in the dispersion relation, or equivalently in the liquid state partial static structure factors.