Dynamical phase transition in programmable multicomponent crystals

Complex synthetic materials such as DNA-programmed molecular and colloidal crystals can assemble into multiple distinct polymorphs from a set of shared components. Because molecular self-assembly is an intrinsically nonequilibrium process, the kinetics of the assembly process control the robustness of the assembly of a specific polymorph. We use a lattice model to study the seeded growth of prototypical multicomponent crystals, where different unit cell designs can be encoded through directional interactions. Our simulation results suggest that a dynamical phase transition separates the stable assembly of specific unit cell designs from disordered crystal growth. From our simulations and a dynamical mean-field analysis, we obtain a supersaturation-dependent dynamical phase diagram that reveals the existence of a critical number of encoded unit cells, below which the seeded unit cell design can be reliably grown and beyond which only the disordered phase is stable. Close to the critical number of encoded unit cells, we observe a supersaturation-dependent disordered-phase wetting layer on the growing unit cell, consistent with a first-order dynamical phase transition. Our insights into the nature of this dynamical phase transition suggest design rules for the self-assembly of multicomponent molecular and colloidal crystals, along with strategies for improving the robustness of multi-polymorph crystallization.