Kundu Sumanta, Mandal Dipanjan
Department of Earth and Space Science, Osaka University, 560-0043 Osaka, Japan.
Department of Physics, University of Warwick, Coventry CV4 7AL, United Kingdom.
Phys Rev E. 2021 Apr;103(4-1):042134. doi: 10.1103/PhysRevE.103.042134.
Jamming and percolation transitions in the standard random sequential adsorption of particles on regular lattices are characterized by a universal set of critical exponents. The universality class is preserved even in the presence of randomly distributed defective sites that are forbidden for particle deposition. However, using large-scale Monte Carlo simulations by depositing dimers on the square lattice and employing finite-size scaling, we provide evidence that the system does not exhibit such well-known universal features when the defects have spatial long-range (power-law) correlations. The critical exponents ν_{j} and ν associated with the jamming and percolation transitions, respectively, are found to be nonuniversal for strong spatial correlations and approach systematically their own universal values as the correlation strength is decreased. More crucially, we have found a difference in the values of the percolation correlation length exponent ν for a small but finite density of defects with strong spatial correlations. Furthermore, for a fixed defect density, it is found that the percolation threshold of the system, at which the largest cluster of absorbed dimers first establishes the global connectivity, gets reduced with increasing the strength of the spatial correlation.
在规则晶格上进行的标准随机顺序粒子吸附过程中的堵塞和逾渗转变,由一组通用的临界指数来表征。即使存在随机分布的禁止粒子沉积的缺陷位点,普适类仍然保持。然而,通过在正方形晶格上沉积二聚体并采用有限尺寸标度进行大规模蒙特卡罗模拟,我们提供了证据表明,当缺陷具有空间长程(幂律)相关性时,该系统不会表现出此类众所周知的普适特征。分别与堵塞和逾渗转变相关的临界指数νₖ和ν,对于强空间相关性而言是非普适的,并且随着相关强度的降低,它们会系统地趋近各自的普适值。更关键的是,我们发现对于具有强空间相关性的少量但有限密度的缺陷,逾渗关联长度指数ν的值存在差异。此外,对于固定的缺陷密度,发现系统的逾渗阈值(即吸收二聚体的最大簇首次建立全局连通性时的阈值)会随着空间相关性强度的增加而降低。