Frustration and Melting of Colloidal Molecular Crystals

TL;DR

This paper uses numerical simulations to explore complex melting behaviors and frustration effects in colloidal molecular crystals on 2D substrates, revealing novel states and multi-step melting processes.

Contribution

It introduces new colloidal crystalline states and multi-step melting phenomena on square and triangular substrates, highlighting frustration effects at half-integer fillings.

Findings

Discovery of novel colloidal crystalline states

Observation of multi-step melting involving rotation and hopping

Agreement with recent experimental results

Abstract

Using numerical simulations we show that a variety of novel colloidal crystalline states and multi-step melting phenomena occur on square and triangular two-dimensional periodic substrates. At half-integer fillings different kinds of frustration effects can be realized. A two-step melting transition can occur in which individual colloidal molecules initially rotate, destroying the overall orientational order, followed by the onset of interwell colloidal hopping, in good agreement with recent experiments.