Determination of the Critical Exponents for the IsotropicNematic Phase Transition in a Sys.pdf

epl draft 8 Determination of the critical exponents for the 0 0 isotropic-nematic phase transition in a system of 2 r long rods on two-dimensional lattices: universality p A of the transition 1 2 ] D. A. Matoz-Fernandez, D. H. Linares and A. J. Ramirez-Pastor h c Departamento de F´ısica, Instituto de F´ısica Aplicada, Universidad Nacional de San Luis- e m CONICET, Chacabuco 917, 5700 San Luis, Argentina - t a t PACS 05.50.+q – Lattice theory and statistics (Ising, Potts,etc.) s . PACS 64.70.Md – Transitions in liquid crystals t a PACS 75.40.Mg – Numerical simulation studies m- Abstract. - Monte Carlo simulations and finite-size scaling analysis have been carried out to study d the critical behavior and universality for the isotropic-nematic phase transition in a system of long n straight rigid rods of length k (k-mers) on two-dimensional lattices. The nematic phase, charac- o terized by a big domain of parallel k-mers, is separated from the isotropic state by a continuous c 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 2 for square lattices and the three-state Potts universality class for triangular lattices. v 5 9 3 0 . 8 Introduction. – The study of systems of large particles in solution is one of the central 0 problems in statistical mechanics and has been attracting a great deal of interest since long 7 ago. Onsager [1] predicted that very long and thin rods interacting with only excluded 0 : volume