Ground state structure and interactions between dimeric 2D Wigner crystals

TL;DR

This study uses computer simulations to analyze the ground state structures and interactions of two-dimensional Wigner crystals composed of point-like charges and charged dimers, revealing five crystalline phases and phase transitions involving translational and orientational order.

Contribution

It introduces a detailed simulation analysis of dimeric Wigner crystals, highlighting phase behavior and ordering transitions not previously characterized.

Findings

Five distinct crystalline phases identified with increasing interlayer distance.

Phase transitions involve changes in translational and orientational ordering.

Dimeric ions exhibit unique orientational ordering transitions.

Abstract

We study the ground state ordering and interactions between two two-dimensional Wigner crystals on neutralizing charged plates by means of computer simulation. We consider crystals formed by (i) point-like charges and (ii) charged dimers, which mimic the screening of charged surfaces by elongated multivalent ions such as aspherical globular proteins, charged dendrimers or short stiff polyelectrolytes. Both systems, with point-like and dimeric ions, display five distinct crystalline phases on increasing the interlayer distance. In addition to alteration of translational ordering within the bilayer, the phase transitions in the dimeric system are characterized by alteration of orientational ordering of the ions.