Effect of the number of defect particles on the structure and dispersion relation of a two-dimensional dust lattice system

The effect of the number of defect particles on the structure and dispersion relations of a two-dimensional (2D) dust lattice is studied by molecular dynamics (MD) simulation. The dust lattice structures are characterized by particle distribution, nearest neighbor configuration and pair correlation function. The current autocorrelation function, the dispersion relation and sound speed are used to represent the wave properties. The wave propagation of the dust lattice closely relates to the lattice structure. It shows that the number of defect particles can affect the dust lattice local structure and then affect the dispersion relations of waves propagating in it. The presence of defect particles has a greater effect on the transverse waves than on the longitudinal waves of the dust lattice. The appropriate number of defect particles can weaken the anisotropy property of the lattice.