Melting of Colloidal Molecular Crystals on Triangular Lattices

TL;DR

This paper investigates the phase behavior of colloidal particles on a triangular lattice, revealing diverse phases and transitions through analytical and simulation methods, with implications for experimental systems.

Contribution

It introduces a model treating colloids as rigid composites with discrete degrees of freedom, analyzing complex phase diagrams analytically and via simulations.

Findings

Identification of multiple novel phases including 'herring bone' and 'Japanese 6 in 1'

Development of a phase diagram for colloidal systems on triangular lattices

Analytical and Monte Carlo methods used to analyze phase transitions

Abstract

The phase behavior of a two-dimensional colloidal system subject to a commensurate triangular potential is investigated. We consider the integer number of colloids in each potential minimum as rigid composite objects with effective discrete degrees of freedom. It is shown that there is a rich variety of phases including ``herring bone'' and ``Japanese 6 in 1'' phases. The ensuing phase diagram and phase transitions are analyzed analytically within variational mean-field theory and supplemented by Monte Carlo simulations. Consequences for experiments are discussed.