Fig. 2

(Color online) The equilibrium phase diagram of the Ising model with cluster interaction. The blue line indicates the anisotropy transition which takes place between the paramagnetic and cluster phases. The red and yellow lines, represent the Ising like transition points. The black dashed lines indicate \(J_3=1/4\) and \(J_3=5/2\) as reference lines to enhance the illustration of the critical points at \(h=-1/2\) and \(h=3/2\).