Kwon S, Lee J, Park H
Department of Physics, Inha University, Inchon 402-751, Korea.
Phys Rev Lett. 2000 Aug 21;85(8):1682-5. doi: 10.1103/PhysRevLett.85.1682.
It has been generally believed that hard core interaction is irrelevant to absorbing-type critical phenomena because the particle density is so low near an absorbing phase transition. We study the effect of hard core interaction on the N-species branching annihilating random walks with two offspring and report that hard core interaction drastically changes the absorbing-type critical phenomena in a nontrivial way. Through a Langevin equation-type approach, we predict analytically the values of the scaling exponents, nu( perpendicular) = 2, z = 2, alpha = 1/2, and beta = 2 in one dimension for all N>1. Direct numerical simulations confirm our prediction. When the diffusion coefficients for different species are not identical, nu( perpendicular) and beta vary continuously with the ratios between the coefficients.
人们普遍认为，硬核相互作用与吸收型临界现象无关，因为在吸收相变附近粒子密度非常低。我们研究了硬核相互作用对具有两个后代的N物种分支湮灭随机游走的影响，并报告硬核相互作用以一种非平凡的方式极大地改变了吸收型临界现象。通过一种朗之万方程类型的方法，我们解析地预测了对于所有N>1的一维情况下的标度指数值，即ν(⊥)=2，z = 2，α = 1/2，以及β = 2。直接的数值模拟证实了我们的预测。当不同物种的扩散系数不相等时，ν(⊥)和β随系数之间的比率连续变化。
