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 ${\rho }_{d,s}\simeq 0.046$ and ${\rho }_{d,h}\simeq 0.123$.

• Received 27 February 2023
• Revised 16 May 2023
• Accepted 1 June 2023

DOI:https://doi.org/10.1103/PhysRevLett.130.258202