Magnetic and thermal properties of a one-dimensional spin-1 model
  We study the one-dimensional S=1 Blume-Emery-Griffiths model. Upon transforming the spin model into an equivalent fermionic model, we provide the exact solution within the Green's function and equations of motion formalism. We show that the relevant response functions as well as thermodynamic quantities can be determined, in the whole parameters space, in terms of a finite set of local correlators. Furthermore, considering the case of an antiferromagnetic chain with single-ion anisotropy in the presence of an external magnetic field, we find three plateaus in the magnetization curve; in the neighborhood of the endpoints of the intermediate plateau, the specific heat shows a double peak structure. 
F. Mancini, F. P. Mancini