Simulações entrópicas do modelo de Baxter-Wu unidimensional

• Autor(a) principal: Sousa, Rhayson Almeida de
• Data de Publicação: 2020
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Repositório Institucional da UFG
• Texto Completo: http://repositorio.bc.ufg.br/tede/handle/tede/10697
• topic: O modelo de Baxter-Wu; Rede unidimensional; Simulação entrópica; Transição de fase; The Baxter-Wu model; One-dimensional lattice; Entropic simulation; Phase transition; CIENCIAS EXATAS E DA TERRA::FISICA

The Baxter-Wu model was initially proposed in 1972 by D. W. Wood and H. P. Griffiths and solved exactly by R. Baxter and F. Wu. The model is defined in a two-dimensional triangular lattice that can be decomposed into three triangular sub-lattice, so that any triangular face contains a spin from each sub-lattice at each vertex. The ground state of the model is four times degenerate, being formed by the positive ferromagnetic phase and three ferrimagnetic phases. The model also has a proposal for a three-dimensional lattice made by L. N. Jorge, L. S. Ferreira and A. A. Caparica inspired by the two-dimensional lattice, the ground state being only formed by the ferromagnetic phase and has a discontinuous order-disorder transition. The Baxter-Wu model of one-dimensional lattice was proposed by M. F. Calvacante and J. A. Plascak in the study of the Baxter-Wu model in different dimensionalities of lattices through the mean-field approach, where it presented a discontinuous order-disorder transition. In this work we studied the one-dimensional Baxter-Wu model using state counting and entropic simulations. We calculated the thermodynamic properties for different field and temperature values and obtained the ground state settings for three different regions that are separated at H = 0 and H = −3. Only on the interfaces we found out a finite size effect and a finite size study was performed for H = 0, obtaining the critical temperature and the critical exponents.