Fizika Nizkikh Temperatur: Volume 46, Number 9 (September 2020), p. 1054-1061    ( to contents , go back )

Structure of different shape 2D electron clusters at low temperatures

V. E. Syvokon

B. Verkin Institute for Low Temperature Physics and Engineering of the National Academy of Sciences of Ukraine Kharkiv 61103, Ukraine
E-mail: sivokon@ilt.kharkov.ua

Received March 13, 2020, published online July 22, 2020

Abstract

Structure of two-dimensional clusters is studied by the molecular dynamics method. The clusters can be created in the electron systems over superfluid helium with holding electrodes of triangular, square, hexagonal, and round shapes. The surface electron density of 108 cm–2 is fixed. The clusters studied contain from 3 to 406 electrons. Spatial configurations corresponding to temperature 10–2 K are calculated. The cluster shape influences es-sentially on the spatial ordering of the electrons. If cluster symmetry is consistent with the electron crystal triangular symmetry, the ideal defect-free clusters are possible with certain numbers of electrons. In other cases the clusters contain defects. The additional external electric field applied to the cluster changes essentially the electron configuration.

Key words: Wigner crystal, spatial structure, molecular dynamics.

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