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Resolving structural transitions in spherical dust clusters

H. Thomsen and M. Bonitz

  • Institut für Theoretische Physik und Astrophysik, Christian-Albrechts-Universität zu Kiel, D-24098 Kiel, Germany

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Phys. Rev. E 91, 043104 – Published 21 April, 2015

DOI: https://doi.org/10.1103/PhysRevE.91.043104

Abstract

Finite systems in confining potentials are known to undergo structural transitions similar to phase transitions. However, these systems are inhomogeneous, and their “melting” point may depend on the position in the trap and vary with the particle number. Focusing on three-dimensional Coulomb systems in a harmonic trap a rich physics is revealed: in addition to radial melting we demonstrate the existence of intrashell disordering and intershell angular melting. Our analysis takes advantage of a novel melting criterion that is based on the spatial two- and three-particle distribution functions and the associated reduced entropy which can be directly measured in complex plasma experiments.

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Phys. Rev. E 91, 043104– Published 21 April, 2015
  • Received 10 October 2014
  • Revised 27 January 2015

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