arXiv:cond-mat/0002214 · Physical Review Letters
Does Hard Core Interaction Change Absorbing-Type Critical Phenomena?
Sungchul Kwon, Jysoo Lee, Hyunggyu Park
Abstract
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, ${\ensuremath{\nu}}_{\ensuremath{\perp}}\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}2$, $z\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}2$, $\ensuremath{\alpha}\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}1/2$, and $\ensuremath{\beta}\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}2$ in one dimension for all $N>1$. Direct numerical simulations confirm our prediction. When the diffusion coefficients for different species are not identical, ${\ensuremath{\nu}}_{\ensuremath{\perp}}$ and $\ensuremath{\beta}$ vary continuously with the ratios between the coefficients.