Effective interactions and melting of a one dimensional defect lattice within a two-dimensional confined colloidal solid

TL;DR

This study uses Monte Carlo simulations to explore how a confined two-dimensional colloidal crystal develops a defect lattice, revealing defect interactions and melting behavior influenced by reduced dimensionality.

Contribution

It provides the first detailed analysis of defect interactions and melting phenomena in a one-dimensional defect array within a confined 2D colloidal solid.

Findings

Defect interactions are characterized and quantified.

A finite defect chain melts at a specific temperature.

Structural transition involves a soliton staircase formation.

Abstract

We report Monte Carlo studies of a two-dimensional soft colloidal crystal confined in a strip geometry by parallel walls. The wall-particle interaction has corrugations along the length of the strip. Compressing the crystal by decreasing the distance between the walls induces a structural transition characterized by the sudden appearance of a one-dimensional array of extended defects each of which span several lattice parameters, a "soliton staircase". We obtain the effective interaction between these defects. A Lindemann criterion shows that the reduction of dimensionality causes a finite periodic chain of these defects to readily melt as the temperature is raised. We discuss possible experimental realizations and speculate on potential applications.