Self-Diffusion in 2D Dusty Plasma Liquids: Numerical Simulation Results

Abstract

We perform Brownian dynamics simulations for studying the self-diffusion in two-dimensional (2D) dusty plasma liquids, in terms of both mean-square displacement and velocity autocorrelation function (VAF). Super-diffusion of charged dust particles has been observed to be most significant at infinitely small damping rate $\gamma$ for intermediate coupling strength, where the long-time asymptotic behavior of VAF is found to be the product of $t^{-1}$ and $\exp (-\gamma t)$. The former represents the prediction of early theories in 2D simple liquids and the latter the VAF of a free Brownian particle. This leads to a smooth transition from super-diffusion to normal diffusion, and then to sub-diffusion with an increase of the damping rate. These results well explain the seemingly contradictory scattered in recent classical molecular dynamics simulations and experiments of dusty plasmas.

10 pages 5 figures, accepted by PRL

Cited by in corpus (2)

• Brownian Dynamics of charged particles in a constant magnetic field
• Wave spectra of 2D Yukawa solids and liquids in the presence of a magnetic field