Termodinâmica de modelos integráveis

Abstract

In this work we study the thermodynamics of integrable spin chains, like the Heisenberg model and it's spin-s generalization with competing interactions. We have used the quantum transfer matrix approach and obtained a finite set of non-linear integral equations in each case. From the numerical solution of these equations we plotted phase diagrams by varying the parameters h (external magnetic field) and ωj, which couples the different competitive interactions.