Effects of dust particle number on the structure and dynamics in a binary complex plasma system by Langevin dynamics simulation

Abstract

In this paper, Langevin dynamics simulation is used to study the influence of particle number on the structures and dynamics of a binary complex plasma, in which two kinds of particles with different masses are considered. The structures of the binary system are characterized by particle distribution, nearest-neighbor, and pair correlation function. The dynamics of the system are characterized by the evolution of average speed and kinetic energy as time, the mean square displacement (MSD) and self-diffusion coefficient of the binary particles. The lattice structures and the dynamics evolution of binary particles versus the particle number are investigated in detail in this paper. The space distribution shows that the binary particles easily fully separate themselves for a small particle number. The dynamics evolutions indicate that small particles reach the system center first, and then are pushed out by the later reached large particles. As the number of particles increases, the system becomes more ordered and the kinetic energy difference between the two kinds of particles becomes smaller. This study shows that the structure and dynamics of a binary complex plasma can be affected by dust particle number.