2D ISING-HEISENBERG MODEL WITH QUARTIC INTERACTION

We propose a two-dimensional spin-1/2 Ising-Heisenberg model with quartic interaction. In this sense the phase diagram for the model at zero temperature is studied, obtaining four different configurations for the unitary cell. It should be observed that using the rotation and spin inversion symmetry we have only three spin configurations that are relevant. In addition, the model under consideration will be straightforwardly mapped to the exactly solved eight-vertex model and the conditions for obtaining an exact solution will be investigated. The analysis was performed for two different conditions, namely, where the free fermion condition (FFC) and the symmetrical eight-vertex condition (SEVC) are satisfied.