Statistical physics of the freely jointed chain
Statistical physics of the freely jointed chain
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DOI：
10.1103/physreve.53.6297
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发表时间：
1996-06-01
影响因子：
2.4
通讯作者：
Mazars, M
中科院分区：
文献类型：
--
作者：
Mazars, M
利用S. F. Edwards和A. G.固特异[J. Phys. A 5，965（1972）; 5，1188（1972）]中，我们从自由连接链的经典哈密顿量出发，对自由连接链的正则配分函数进行了完整的计算。我们展示了如何减少的限制相空间的理想气体的单体的相空间的FJC，以及它们如何允许一个找到规范的配分函数。利用该函数，可以研究FJC的物理性质，也可以通过拉普拉斯变换构造其它物理系综。因此，我们定义了一个巨正则系综的单体数的FJC可以波动，在这个系综中，无限长的FJC是在低温和高温下的渐近状态。计算了FJC的临界指数γ和nu，发现它们与高斯聚合物指数相等。本文还讨论了FJC的性质与正则格上的随机游动之间的联系。
Using the method of constraints proposed by S. F. Edwards and A. G. Goodyear [J. Phys. A 5, 965 (1972); 5, 1188 (1972)], we do a complete calculation of the canonical partition function of a freely jointed chain (FJC) from its classical Hamiltonian. We show how the constraints reduce the phase space of an ideal gas of monomers to the phase space of a FJC, and how they permit one to find the canonical partition function. By using this function, it is possible to study thermodynamical properties of FJC's and to build other thermodynamical ensembles via Laplace transforms. Thus we define a grand canonical ensemble where the monomer number of the FJC can fluctuate; in this ensemble, the FJC of infinite length is the asymptotic state at low and high temperatures. The critical exponents gamma and nu for FJC's are calculated and found to be equal to the Gaussian polymer exponents. Connections between the properties of FJC's and random walks on regular lattices are also discussed.