Critical Behavior of self-assembled rigid rods on 2D lattices

LÓPEZ, L. G.; LINARES D. H.; RAMIREZ PASTOR A. J.

Bahía Blanca-Bs. As.

Congreso; TREFEMAC XII; 2014

Monte Carlo simulations and finite-size scaling (FSS) analysis have been carried out to study the critical behavior of self-assembled rigid rods (SARRs) on 2D lattices. The SARRs model is a two-dimensional system of monomers, with two bonding sites, that polymerize reversibly into chains with restricted orientations and, at the same time, undergo a continuous isotropic-nematic IN transition. A complete phase diagram was obtained as a function of temperature and density. In addition, the site percolation was studied. A critical line separating a percolating isotropic region from a non-percolating isotropic region was determined. For the square lattice case, at intermediate coverage, it was shown that the system under study represents an interesting case where the use of different statistical ensembles (canonical or grand canonical) leads to different and well-established universality classes (q= 1 Potts type or q= 2 Potts type, respectively). Corrections to scaling are necessary in the canonical ensemble, but, why are the percolation exponents obtained in this point?