Two-Dimensional Melting of two- and three-component mixtures

We elucidate the interplay between diverse two-dimensional melting pathways and establish solid/hexatic and hexatic/liquid transition criteria via the numerical simulations of the melting transition of two- and three-component mixtures of hard polygons and disks. We show that a mixture's melting pathway may differ from its components and demonstrate eutectic mixtures that crystallize at a higher density than their pure components. Comparing the melting scenario of many two- and three-component mixtures, we establish universal melting criteria: the solid and hexatic phases become unstable as the density of topological defects respectively overcomes $\rho_{d,{\rm s}} \simeq 0.046$ and $\rho_{d,{\rm h}}\simeq 0.123$.