Critical exponents and universality for the isotropic-nematic phase transition in a system of long rigid rods on a lattice

L.G LÓPEZ; MATOZ FERNANDEZ, DANIEL ALEJANDRO; D. H. LINARES; A. J. RAMIREZ-PASTOR

Cairns, Queensland

Conferencia; XXIV IUPAP International Conference on Statistical Physics (StatPhys24); 2010

nternational Union for Pure and Applied Physics

Monte Carlo simulations and finite-size scaling analysis have been carried out to study the critical behavior and universality for the isotropic-nematic (IN) phase transition in a system of long straight rigid rods of length k (k-mers) on two-dimensional lattices. The nematic phase, characterized by a big domain of parallel k-mers, is separated from the isotropic state by a continuous transition occurring at a finite density. The determination of the critical exponents, along with the behavior of Binder cumulants, indicate that the transition belongs to the 2D Ising universality class for square lattices and the three-state Potts universality class for honeycomb and triangular lattices. Finally, the study was extended to a system of monomers on two dimensional lattices that, by decreasing temperature or increasing density, polymerize reversibly into chains (or self-assembled rigid rods) with a discrete number of allowed directions and, at the same time, undergo a continuous IN transition. The results show that the self-assembly process affects the nature of the IN transition.