0000000000868939
AUTHOR
L. ŠAmaj
Phase Transitions in Multicomponent Widom-Rowlinson Models
We use Monte Carlo techniques to study the phase diagram of multicomponent Widom-Rowlinson models on a square lattice: there are M species all with the same fugacity z and a nearest neighbor hard core exclusion between unlike particles. For M between two and six there is a direct transition from the gas phase at z z d (M). For M ≥ 7 there is an intermediate ordered phase in which the even (or odd) sublattice is occupied preferentially by particles chosen at random from any of the species. The existence of such an intermediate phase was proven earlier for M ≥ M 0, M 0 very large. Exact calculations on the Bethe lattice give M0 = 4.
Ordering and demixing transitions in multicomponent Widom-Rowlinson models.
We use Monte Carlo techniques and analytical methods to study the phase diagram of multicomponent Widom-Rowlinson models on a square lattice: there are M species all with the same fugacity z and a nearest neighbor hard core exclusion between unlike particles. Simulations show that for M between two and six there is a direct transition from the gas phase at z < z_d (M) to a demixed phase consisting mostly of one species at z > z_d (M) while for M \geq 7 there is an intermediate ``crystal phase'' for z lying between z_c(M) and z_d(M). In this phase, which is driven by entropy, particles, independent of species, preferentially occupy one of the sublattices, i.e. spatial symmetry but not …