Fig. 1: Ising model with molecule formation.
From: Microscopic origin of abrupt mixed-order phase transitions
Demonstration of the possible states of the system’s initial configuration and possible evolution steps of the Ising model with molecule formation. Each particle can be in three possible states: spin up (yellow), spin down (blue), or be part of a molecule (red) with effectively zero spin. Molecules are formed on the underlying network; any two particles joined by a link can form a molecule. The underlying network is effectively evolving due to the formation of molecules. While the Ising-interaction links between nearest-neighbor-free particles (green) are active, links to particles that are part of a molecule are inactive (gray). The system can evolve by randomly choosing two neighboring particles and creating a new molecule, destroying a molecule and making the particles free, or changing the spin of one of the particles. The first two types of evolution effectively change the interaction network of the system.
