Microphase separation as the cause of structural complexity in 2D liquids

Complex behavior in glassforming liquids is associated with formation of a mosaic of different structures. Using bond order parameters together with topological characteristics of the bond network, we show that in the mosaic of crystalline and amorphous clusters found in a 2D liquid the difference between structural sub- components translates into a difference between two coexisting phases. We suggest that the observed microphase separated mosaic is a 2D realization of what is usually invoked to explain special features found in 3D complex liquids. Conditions favoring mosaic stability are discussed; these conditions include a new type of critical behavior and long-range correlations between sub-component clusters.