Structural transitions of finite spherical Yukawa crystals

TL;DR

This paper investigates how screening affects the shell configurations of finite spherical Yukawa crystals, revealing anomalous behaviors through extensive molecular dynamics simulations.

Contribution

It provides a detailed analysis of ground state shell configurations and their changes across a wide range of screening parameters for clusters with 11 to 60 particles.

Findings

Increased screening leads to more particles in inner shells.

Identification of three types of anomalous configuration behaviors.

Extensive molecular dynamics simulations used for analysis.

Abstract

Small three-dimensional strongly coupled clusters of charged particles in a spherical confinement potential arrange themselves in nested concentric shells. If the particles are immersed into a background plasma the interaction is screened. The cluster shell configuration is known to be sensitive to the screening strength. With increased screening an increased population of the inner shell(s) is observed. Here, we present a detailed analysis of the ground state shell configurations and configuration changes in a wide range of screening parameters for clusters with particle numbers $N$ in the range of 11 to 60. We report three types of anomalous behaviors which are observed upon increase of screening, at fixed $N$ or for an increase of $N$ at fixed screening. The results are obtained by means of extensive first principle molecular dynamics simulations.