arXivDaily arXiv每日学术速递 周一至周五更新
arXiv周末暂无论文更新,休息一下吧,周末愉快~~
arXiv 1708.08154cond-mat.soft
收藏

波动膜和界面的镜面反射的统计力学

Statistical mechanics of specular reflections from fluctuating membranes and interfaces

Amir Azadi, David R. Nelson

摘要:

本文研究了在几何光学极限下,当光散射离开处于热力学平衡的起伏界面和薄膜时,镜面反射点的密度。我们专注于在两个维度的热力学平衡的毛细重力界面(其特征在于由表面张力)和流体膜(由弯曲刚度控制)的统计力学。Berry,Nye,Longuet-Higgins等人的工作的基础上,我们表明,镜面反射点的统计是完全由三个基本的长度尺度,即相关长度$ξ$,微观长度尺度$\ell$和界面或膜的整体尺寸$L$的特征。通过结合数值模拟的标度分析,我们证实了存在的标度律的镜面反射点,$n_{spec}$,在两个维度上的密度,由$n_{spec}\propto\ell^{-1}$在限制薄波动界面的界面厚度$\ell\llξ_I$。因此,镜面反射的密度发散的波动界面在消失的厚度的限制,并显示界面毛细重力相关长度$ξ_I$上没有依赖性。虽然在张力下的流体膜在$n_{spec}\propto\left(ξ_M\ell\right)^{-1/2}$中也表现出发散,但是在这种情况下,镜面反射的数量可以通过减小膜相关长度$ξ_{M}$来增加。

英文摘要:

We study the density of specular reflection points in the geometrical optics limit when light scatters off fluctuating interfaces and membranes in thermodynamic equilibrium. We focus on the statistical mechanics of both capillary-gravity interfaces (characterized by a surface tension) and fluid membranes (controlled by a bending rigidity) in thermodynamic equilibrium in two dimensions. Building on work by Berry, Nye, Longuet-Higgins and others, we show that the statistics of specular points is fully characterized by three fundamental length scales, namely, a correlation length $ξ$, a microscopic length scale $\ell$ and the overall size $L$ of the interface or membrane. By combining a scaling analysis with numerical simulations, we confirm the existence of a scaling law for the density of specular reflection points, $n_{spec}$, in two dimensions, given by $n_{spec}\propto\ell^{-1}$ in the limit of thin fluctuating interfaces with the interfacial thickness $\ell\llξ_I$. The density of specular reflections thus diverges for fluctuating interfaces in the limit of vanishing thickness and shows no dependance on the interfacial capillary-gravity correlation length $ξ_I$. Although fluid membranes under tension also exhibit a divergence in $n_{spec}\propto\left(ξ_M\ell\right)^{-1/2}$, the number of specular reflections in this case can grow by decreasing the membrane correlation length $ξ_{M}$.

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。

↑