软Yukawa-Langevin系统的临界涨落和反常输运
Critical fluctuations and anomalous transport in soft Yukawa-Langevin systems
摘要：
Langevin动力学模型的模拟表明出现的临界波动和反常的颗粒输运已被观察到在实验中的“软”准二维尘埃等离子体团簇。有人认为，这些异常来自特定的非平衡物理，但我们的模型不包含这样的物理：颗粒被限制在一个外部的潜力，通过静态汤川力相互作用，并受到随机加热和中性耗散。一个显着的特点是出现的尖峰概率分布的晶粒位移$ξ(τ)$的时间尺度$τ<τ_Δ$，其中$τ_Δ$是标准差$σ(τ)\equiv < ξ^2(τ) >^{1/2}$接近平均晶粒间距离$Δ$的时间。其他的是在$Δ$的倍数上的分布中的驼峰的发展，反常的赫斯特指数，以及在时间尺度$τ>τ_Δ$上从尖峰向高斯位移分布的转变。后者是一个签名的不稳定性，在这里解释为一个过渡，从突发运输与跳跃在中间的时间尺度上的旋涡流在较长的时间尺度上。
英文摘要：
Simulation of a Langevin-dynamics model demonstrates emergence of critical fluctuations and anomalous grain transport which have been observed in experiments on "soft" quasi-two-dimensional dusty plasma clusters. It has been suggested that these anomalies derive from particular non-equilibrium physics, but our model does not contain such physics: the grains are confined by an external potential, interact via static Yukawa forces, and are subject to stochastic heating and dissipation from neutrals. One remarkable feature is emergence of leptokurtic probability distributions of grain displacements $ξ(τ)$ on time-scales $τ<τ_Δ$, where $τ_Δ$ is the time at which the standard deviation $σ(τ)\equiv < ξ^2(τ) >^{1/2}$ approaches the mean inter-grain distance $Δ$. Others are development of humps in the distributions on multiples of $Δ$, anomalous Hurst exponents, and transitions from leptokurtic towards Gaussian displacement distributions on time scales $τ>τ_Δ$. The latter is a signature of intermittency, here interpreted as a transition from bursty transport associated with hopping on intermediate time scales to vortical flows on longer time scales.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
