Equation of state calculations for two-dimensional dust coulomb crystal at near zero temperature by molecular dynamics simulations

Abstract

Dust particles observed in universe as well as in laboratory and technological plasma devices are still under investigation. At low temperature, these particles are strongly negatively charged and are able to form a 2D or 3D coulomb crystal. In this work, our aim was to check the ideal gas law validity for a 2D single-layer dust crystal recently reported in the literature. For this purpose, we have simulated, using the molecular dynamics method, its thermodynamic properties for different values of dust particles number and confinement parameters. The obtained results have allowed us to invalidate the ideal gas behaviour and to propose an effective equation of state which assumes a near zero dust temperature. Furthermore, the value of the calculated sound velocity was found to be in a good agreement with experimental data published elsewhere.

Equilibrium configuration of self-gravitating charged dust clouds: Particle approach

“…Some other examples where quadratic scaling is found to be valid in the even in the presence of correlations includes the simulations of Charan et al where P d ∝ n 2 d scaling is seen in the regions where dust particles are compressed by external gravity and dust is strongly coupled [43]. The simulation of Djouder et al for dust monolayer confined by parabolic potential shows that the equation of state near zero dust temperature follows the relation P d ∝ n 2∼2.165 d for a wide range of densities near the dust crystal [44].…”

Isothermal equation of state of three dimensional Yukawa gas

“…The result of this simulation show P d ∝ n 2 d scaling in the bottom region where dust particles are compressed and strongly coupled. In simulation of Djouder et al dust monolayer is confined using parabolic potential and equation of state is established near zero dust temperature 13 . Their equation of state also suggests P d ∝ n 2∼2.165 d for a wide range of density near dust crystal.…”

“…Unlike the case of normal electron-ion plasma where the pressure follows the ideal gas relation P = nT where n is the number density and T is the temperature, the dust pressure is expected to be complex due to presence of strong correlation effects. A number of authors have studied the equation of state of 2D and 3D Yukawa particles both analytically [4][5][6][7][8][9][10][11] and using MD simulations [12][13][14][15][16] . Most of these simulations have been carried out using periodic boundary conditions.…”

“…In order to take into account confinement effects we consider perfectly reflecting boundary condition in our MD simulations. The confinement effects may also be accounted for by considering a confining potential 13,22,24 however we have chosen to use reflecting boundary conditions which are simpler to implement. The results of the MD simulations show that in weak coupling regime the electrostatic pressure scales as n 2 d and is significantly bigger than the dust thermal pressure.…”

Electric field in two-dimensional complex plasma crystal: Simulated lattices

“…Also, usually their lattices have hexagonal symmetry. [14][15][16][17][18] In most papers, spring force is used as confinement force: [19][20][21][22][23] F x = −k x x, F y = −k y y.…”