Generic properties of a quasi-one dimensional classical Wigner crystal

TL;DR

This paper investigates the structural, dynamical, and melting properties of a quasi-one-dimensional classical Wigner crystal with screened Coulomb interactions, revealing complex phase transitions, normal modes, and reentrant melting phenomena.

Contribution

It provides a comprehensive analysis of phase diagrams, normal modes, and melting behavior, including the effects of magnetic fields and screening, using analytical and Monte Carlo methods.

Findings

Rich phase diagram with multiple structural transitions

Reentrant melting as a function of density

Anomalous melting temperatures in single chain regime

Abstract

We studied the structural, dynamical properties and melting of a quasi-one-dimensional system of charged particles, interacting through a screened Coulomb potential. The ground state energy was calculated and, depending on the density and the screening length, the system crystallizes in a number of chains. As a function of the density (or the confining potential), the ground state configurations and the structural transitions between them were analyzed both by analytical and Monte Carlo calculations. The system exhibits a rich phase diagram at zero temperature with continuous and discontinuous structural transitions. We calculated the normal modes of the Wigner crystal and the magneto-phonons when an external constant magnetic field $B$ is applied. At finite temperature the melting of the system was studied via Monte Carlo simulations using the $modified$ $Lindemann$ $criterion$ (MLC). The melting temperature as a function of the density was obtained for different screening parameters. Reentrant melting as a function of the density was found as well as evidence of directional dependent melting. The single chain regime exhibits anomalous melting temperatures according to the MLC and as a check we study the pair correlation function at different densities and different temperatures, formulating a different criterion. Possible connection with recent theoretical and experimental results are discussed and experiments are proposed.