Ordemann Anke, Porto Markus, Roman H Eduardo
Institut für Theoretische Physik III, Justus-Liebig-Universität Giessen, Heinrich-Buff-Ring 16, 35392 Giessen, Germany.
Phys Rev E Stat Nonlin Soft Matter Phys. 2002 Feb;65(2 Pt 1):021107. doi: 10.1103/PhysRevE.65.021107. Epub 2002 Jan 17.
The scaling properties of linear polymers on deterministic fractal structures, modeled by self-avoiding random walks (SAW) on Sierpinski lattices in two and three dimensions, are studied. To this end, all possible SAW configurations of N steps are enumerated exactly and averages over suitable sets of starting lattice points for the walks are performed to extract the mean quantities of interest reliably. We determine the critical exponent describing the mean end-to-end chemical distance (-)l(N) after N steps and the corresponding distribution function, P(S)(l,N). A des Cloizeaux-type relation between the exponent characterizing the asymptotic shape of the distribution, for l-->0 and N--> infinity, and the one describing the total number of SAW of N steps is suggested and supported by numerical results. These results are confronted with those obtained recently on the backbone of the incipient percolation cluster, where the corresponding exponents are very well described by a generalized des Cloizeaux relation valid for statistically self-similar structures.
研究了线性聚合物在确定性分形结构上的标度性质,该结构由二维和三维谢尔宾斯基晶格上的自回避随机游走(SAW)建模。为此,精确枚举了N步的所有可能的SAW构型,并对游走的合适起始晶格点集进行平均,以可靠地提取感兴趣的平均量。我们确定了描述N步后平均端到端化学距离〈l(N)〉的临界指数以及相应的分布函数P(S)(l,N)。对于l→0和N→∞,提出了表征分布渐近形状的指数与描述N步SAW总数的指数之间的一种德克洛佐型关系,并得到了数值结果的支持。这些结果与最近在初始渗流团簇的主链上获得的结果进行了对比,在那里相应的指数可以用对统计自相似结构有效的广义德克洛佐关系很好地描述。