8th Liquid Matter Conference September 6-10, 2011 Wien, Austria ...

Thu 811:10-14:00P7.93Hexatic phase in the two-dimensional Gaussian-coremodelSanti Prestipino, 1 Franz Saija, 2 and Paolo Giaquinta 11 University of Messina, Viale F. Stagno d’Alcontres, 98166, Messina, Italy2 National Research Council, Messina, ItalyWe present a Monte Carlo simulation study of the phase behavior of two-dimensional classicalparticles repelling each other through an isotropic Gaussian potential. As in the analogousthree-dimensional case, a reentrant-melting transition occurs upon compression for not too hightemperatures, along with a spectrum of water-like anomalies in the fluid phase. However, intwo dimensions melting is a continuous two-stage transition, with an intermediate hexatic phasewhich becomes increasingly more definite as pressure grows. All available evidence supports theKosterlitz-Thouless-Halperin-Nelson-Young scenario for this melting transition. We expect thatsuch a phenomenology can be checked in confined monolayers of charge-stabilized colloids witha softened core.93