TWO-DIMENSION YUKAVA-LIQUID WITH AN ADDITIONAL WEAK DIPOLE-DIPOLE INTERPARTICLE INTERACTION

Abstract

The system of charged particles interacting through the screened potential of the Yu-
kawa is called the Yukawa system in the modern scientific literature. If this system is highly correlated
and there is a short range order in this system, then it is called a Yukawa liquid. In dusty plasma exper-
iments, Yukawa systems with an additional dipole-dipole interaction between particles are realized. An
additional dipole moment can be induced by ion focusing due to the stationary ion flux and attraction by
a negatively charged dust particle. Using molecular dynamics (MD), this paper presents the results of
calculation of the pair correlation function of a two-dimensional system of dust particles with an addi-
tional dipole-dipole interaction. Comparison with experimental data indicates that the model used can be
applied to explain experimental observation. Also, the results of computation of the diffusion coefficient
are presented. To calculate the diffusion coefficient, the Green-Kubo relation and the data of the auto-
correlation function of particle velocities from the MD simulation of a two-dimensional system were used. It is shown that an additional dipole – dipole interaction leads to a decrease in the diffusion coeffi-
cient. A discussion of the experimental realization of a two-dimensional Yukawa system with an addi-
tional controlled dipole-dipole interaction between dust particles in a complex plasma is given.