10-01U

Strong anisotropy limit allows to establish correspondence between the thermodynamics of two-dimensional classical systems and ground-state energy of correspondent one-dimensional system. Strong interaction limit, being the generalization of strong anisotropy limit, was proposed. Conditions for diagonal and off-diagonal transfer matrix parts which allow found quantum Hamiltonian explicitly was found. Two approximations were compared for two-dimensional spin-$\frac {1}{2}$ Ising model.