Issue
EPL
Volume 77, Number 3, February 2007
Article Number 38003
Number of page(s) 5
Section Interdisciplinary Physics and Related Areas of Science and Technology
DOI http://dx.doi.org/10.1209/0295-5075/77/38003
Published online 24 January 2007
EPL, 77 (2007) 38003
DOI: 10.1209/0295-5075/77/38003

Ground state structure and interactions between dimeric 2D Wigner crystals

V. Lobaskin and R. R. Netz

Physics Department, Technische Universität München - James-Franck-Str., D-85747 Garching, Germany


received 1 August 2006; accepted in final form 5 December 2006; published February 2007
published online 24 January 2007

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.

PACS
82.70.-y - Disperse systems; complex fluids.
64.70.Kb - Solid-solid transitions.
68.47.Pe - Langmuir-Blodgett films on solids; polymers on surfaces; biological molecules on surfaces.

© Europhysics Letters Association 2007