Defects related self-diffusion in a two-dimensional dusty plasma crystal

Abstract

Single-particle motion and self-diffusion in a two-dimensional dusty plasma are investigated by molecular dynamic simulation. The velocity autocorrelation function indicates that the single-particle motion is strongly coupled to the collective motion in the dusty plasma when the coupling parameter is high enough. The point defects play an important role in the particle self-diffusion process. A simple point defect motion model is developed to explain the mechanism of self-diffusion and estimate the self-diffusion coefficient in the dusty plasma. The value of the self-diffusion coefficient calculated by using the model is in agreement with the result obtained from mean square displacement for a two-dimensional dusty plasma crystal.