Molecular dynamics evaluation of self-diffusion coefficients in two-dimensional dusty plasmas  

作　　者：Muhammad Asif Shakoori Misbah Khan Haipeng Li Aamir Shahzad Maogang He Syed Ali Raza Muhammad Asif Shakoori;Misbah Khan;李海鹏;Aamir Shahzad;何茂刚;Syed Ali Raza

机构地区：[1]School of Materials Science and Physics,China University of Mining and Technology,Xuzhou 221116,China [2]Department of Refrigeration and Cryogenic Engineering,School of Energy and Power Engineering,Xi’an Jiaotong University,Xi’an 710049,China [3]Department of Physics,Government College University Faisalabad(GCUF),Allama Iqbal Road,Faisalabad 38000,Pakistan [4]Key Laboratory of Thermo-Fluid Science and Engineering of Ministry of Education(MOE),Xi’an Jiaotong University,Xi’an 710049,China [5]School of Electrical Engineering,Xi’an Jiaotong University,Xi’an 710049,China

出　　处：《Chinese Physics B》2025年第4期457-466,共10页中国物理B(英文版)

基　　金：support of the Fundamental Research Funds for the Central Universities of China(Grant No.2019ZDPY16).

摘　　要：We employ the Green–Kubo(G-K)and Einstein relations to estimate the self-diffusion coefficients(denoted as D_(G)and D_(E),respectively)in two-dimensional(2D)strongly coupled dusty plasmas(SC-DPs)via equilibrium molecular dynamics(EMD)simulations.D_(G)and D_(E)are computed for a broad domain of screening length(κ)and coupling parameters(Г)along with different system sizes.It is observed that both D_(G)and D_(E)decrease linearly with increasing G in warm liquid states and increase with increasingκ.In cold liquid states,the Einstein relation accurately predicts D_(E)in 2D SC-DPs because diffusion motion is close to normal diffusion,but the G-K relation provides overestimations of D_(G),because VACF indicates anomalous diffusion;thus,D_(G)is not accurate.Our new simulation outcomes reveal that D_(G)and D_(E)remain independent of system sizes.Furthermore,our investigations demonstrate that at higher temperatures,D_(G)and D_(E)converge,suggesting diffusion motion close to normal diffusion,while at lower temperatures,these two values diverge.We find reasonable agreement by comparing current and existing numerical,theoretical and experimental data.Moreover,when normalizing diffusion coefficients by the Einstein frequency and testing against the universal temperature scaling law,D_(G)deviates from theoretical curves at low temperatures and k,whereas D_(E)only disagrees with theory at very smallκ(■0.10).These findings provide valuable insight into diagnosing dust component parameters within 2D DP systems and contribute to the broader understanding of diffusion processes in DP environments.

关 键 词：dusty(complex)plasmas self-diffusion coefficients molecular dynamics simulation Green-Kubo and Einstein relations 

分 类 号：O53[理学—等离子体物理]