Emergence of a fluctuation-driven cooperative solidlike phase in Potts model monolayers
Phys. Rev. E 113, 064410 – Published 22 June, 2026
DOI: https://doi.org/10.1103/8wk1-tvg3
Abstract
Cellular Potts model (CPM) simulations display significant variation in dynamics, structural ordering, and observed phase transitions. Such differences may emerge, at least in part, because CPM simulations are not implemented in a uniform manner, specifically in terms of the definitions of cell perimeters and cell contact lengths. These definitions can have a significant effect on cell shape, dynamics, and data reproducibility. Here we explore different implementations of edge length computation and its effects on phase transitions as a function of cellular adhesion energy in confluent monolayers. While we find that edge length definition has only a modest effect on the transition point from fluidlike to solidlike behavior, it strongly impacts the structural order and dynamics of the monolayer across regimes. Lattice-based artifacts from cell-lattice alignment and overcounting of the cell contact length limit cooperative motion and structural order and cause early dynamical arrest. Using an updated, self-consistent implementation that corrects contact length in a manner that mirrors continuum models of cell migration, we find that monolayers undergo a transition from a fluid through a transient hexatic phase into an ordered solidlike phase that retains significant cooperative motion. This cooperative, fluctuation-driven solidlike phase is unique to this updated CPM implementation. Cell shapes in such monolayers are well-behaved and adhere to the expected shape thresholds used as structural indicators in other multicellular systems, making their application and comparison to experimental systems more readily interpretable.
