A hexatic smectic phase with algebraically decaying bond-orientational order

TL;DR

This paper reports the first observation of a hexatic smectic phase with algebraically decaying bond-orientational order in a 3D system, aligning with 2D melting theory predictions, via molecular dynamics simulation.

Contribution

It demonstrates the existence of a hexatic smectic phase with algebraic decay of bond order in a 3D system, confirming theoretical predictions for 2D melting.

Findings

Bond-orientational correlations decay as r^{-1/4}

First simulation evidence of 2D hexatic order in 3D system

Agreement with theoretical predictions for 2D melting

Abstract

The hexatic phase predicted by the theories of two-dimensional melting is characterised by the power law decay of the orientational correlations whereas the in-layer bond orientational order in all the hexatic smectic phases observed so far was found to be long-range. We report a hexatic smectic phase where the in-layer bond orientational correlations decay as $\propto r^{-1/4}$, in quantitative agreement with the hexatic ordering predicted by the theory for two dimensions. The phase was formed in a molecular dynamics simulation of a one-component system of particles interacting via a spherically symmetric potential. This is the first observation of the theoretically predicted two-dimensional hexatic order in a three-dimensional system.