Influence of local correlations on the “homogeneous insulator–superconductor” transition in the domain boundaries of the charge-order phase of a 2D system of a mixed valence

It is demonstrated in the (pseudo)spin $S$ = 1 formalism that the structure of antiphase domain boundaries in the phase of charge ordering of a mixed-valence system of the Cu$^{1+,2+,3+}$ “triplet” type in cuprates on a two-dimensional square lattice depends to a considerable extent on on-site correlation parameter $U$. The results of computer modeling on large square lattices illustrate the change in the boundary structure (from a homogeneous monovalent nonconducting structure of the Cu$^{2+}$ type to a filamentary superconducting one) induced by a relatively small variation of positive $U$ values.