INFLUENCE OF THE DIPOLE-DIPOLE INTERACTION ON THE TRANSPORT AND DYNAMIC PROPERTIES OF DUSTY PLASMAS

Abstract

This paper presents the results of molecular dynamics simulation (MD) of a two-dimensional, strongly-coupled Yukawa liquid, where there is emergence of dipole-dipole interaction. In our case, the dipole moments of the particles are parallel to each other and are equal to each other. Here we consider the effect of an additional dipole-dipole interaction on the following properties: speed of the sound wave, diffusion, and the fluctuation spectrum of the longitudinal and transverse currents. We obtained the results of the speed of the sound wave on the basis of the autocorrelation function of the velocities in the logarithmic form. Analyzing the data, we found a significant increase in the longitudinal velocity of the sound wave due to an additional dipole-dipole interaction. We also investigated the diffusion coefficient by the mean square displacement and found that the additional dipole-dipole interaction suppresses subdiffusion. Finally, we constructed a dispersion of the longitudinal and transverse currents of the Yukawa system, where the width at the half of height corresponds to the lifetime of collective excitations, for various parameters of the dipole-dipole interaction. The wider the spectrum, the shorter the lifetime of collective excitations. We have shown that in the presence of an additional dipole-dipole interaction, the lifetime of the collective excitation of the longitudinal and transverse currents of the Yukawa system changes.

Keywords: dusty plasmas, Yukawa system, dipole-dipole interaction.