# Theory and simulation of two-dimensional nematic and tetratic phases - Condensed Matter > Soft Condensed Matter

Theory and simulation of two-dimensional nematic and tetratic phases - Condensed Matter > Soft Condensed Matter - Descarga este documento en PDF. Documentación en PDF para descargar gratis. Disponible también para leer online.

Abstract: Recent experiments and simulations have shown that two-dimensional systemscan form tetratic phases with four-fold rotational symmetry, even if they arecomposed of particles with only two-fold symmetry. To understand this effect,we propose a model for the statistical mechanics of particles with almostfour-fold symmetry, which is weakly broken down to two-fold. We introduce acoefficient $\kappa$ to characterize the symmetry breaking, and find that thetetratic phase can still exist even up to a substantial value of $\kappa$.Through a Landau expansion of the free energy, we calculate the mean-fieldphase diagram, which is similar to the result of a previous hard-particleexcluded-volume model. To verify our mean-field calculation, we develop a MonteCarlo simulation of spins on a triangular lattice. The results of thesimulation agree very well with the Landau theory.

Autor: Jun Geng, Jonathan V. Selinger

Fuente: https://arxiv.org/