Structure and correlations in two-dimensional Coulomb confined classical artificial atoms

TL;DR

This paper investigates the arrangements and correlations of classical charged particles confined by Coulomb potential in two dimensions, revealing diverse structural configurations and their dependence on charge and confinement parameters.

Contribution

It introduces a detailed analysis of particle configurations in Coulomb-confined classical artificial atoms, including a hydrodynamic approach to highlight correlation effects.

Findings

Identification of various structural configurations such as rings and hexagonal patterns.

Discovery of inner and outer particle arrangements depending on charge ratio.

Comparison of Coulomb confinement effects with parabolic potential cases.

Abstract

The ordering of N equally charged particles (-e) moving in two dimensions and confined by a Coulomb potential, resulting from a displaced positive charge Ze is discussed. This is a classical model system for atoms. We obtain the configurations of the charged particles which, depending on the value of N and Z, may result in ring structures, hexagonal-type configurations and for N/Z~1 in an inner structure of particles which is separated by an outer ring of particles. For N/Z<<1 the Hamiltonian of the parabolic confinement case is recovered. For N/Z~1 the configurations are very different from those found in the case of a parabolic confinement potential. A hydrodynamic analysis is presented in order to highlight the correlations effects.