Self-Diffusion in 2D Dusty Plasma Liquids: Numerical Simulation Results
Autor: | Lu-Jing Hou, Alexander Piel, Padma Kant Shukla |
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Jazyk: | angličtina |
Rok vydání: | 2008 |
Předmět: |
Physics
Dusty plasma Self-diffusion FOS: Physical sciences General Physics and Astronomy Plasma Computational Physics (physics.comp-ph) Physics - Plasma Physics Plasma Physics (physics.plasm-ph) Molecular dynamics Quantum mechanics Product (mathematics) Brownian dynamics Particle Physics - Computational Physics Brownian motion |
Popis: | 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. Comment: 10 pages 5 figures, accepted by PRL |
Databáze: | OpenAIRE |
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