arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 1712.00569cond-mat.stat-mechcond-mat.dis-nncond-mat.softq-bio.SC
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静态无序介质中的非高斯扩散

Non-Gaussian diffusion in static disordered media

Liang Luo, Ming Yi

摘要:

非高斯扩散通常被认为是波动扩散率的结果,其在时间或空间或两者上相关。在这项工作中,我们研究了静态无序介质中的非高斯扩散通过淬火陷阱模型,其中的扩散率是空间相关的。几个独特的效果,由于淬火无序的报告。我们分析估计的扩散系数$D_{\text{dis}}$和它的波动在有限大小的样本。我们展示了非高斯扩散中的种群分裂机制。这导致在$x=0$周围的位移$P(x,t)$的分布中出现尖峰,这在实验中经常观察到。我们检查的粗粒度的扩散图,这是从粒子轨迹重建的保真度。最后,我们提出了一个程序来估计在静态无序环境中的相关长度,其中存储在样本到样本的波动已被利用的信息。

英文摘要:

Non-Gaussian diffusion is commonly considered as a result of fluctuating diffusivity, which is correlated in time or in space or both. In this work, we investigate the non-Gaussian diffusion in static disordered media via a quenched trap model, where the diffusivity is spatially correlated. Several unique effects due to quenched disorder are reported. We analytically estimate the diffusion coefficient $D_{\text{dis}}$ and its fluctuation over samples of finite size. We show a mechanism of population splitting in the non-Gaussian diffusion. It results in a sharp peak in the distribution of displacement $P(x,t)$ around $x=0$, that has frequently been observed in experiments. We examine the fidelity of the coarse-grained diffusion map, which is reconstructed from particle trajectories. Finally, we propose a procedure to estimate the correlation length in static disordered environments, where the information stored in the sample-to-sample fluctuation has been utilized.

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。

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