Transições de fase em sistemas fermiônicos com dimensão espacial compactificada

• Autor(a) principal: Reis, Daniel Medeiros
• Data de Publicação: 2016
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Biblioteca Digital de Teses e Dissertações da UERJ
• Texto Completo: http://www.bdtd.uerj.br/handle/1/12974
• topic: Gross-Neveu; Temperature and chemical potential effects; Spatial compactification; Phase Transition; Modelo de Gross-Neveu; Efeitos de temperatura e potencial químico; Compactificação espacial; Transições de Fase; CNPQ::CIENCIAS EXATAS E DA TERRA::FISICA::FISICA DAS PARTICULAS ELEMENTARES E CAMPOS

In this work, we investigate a planar fermion system in the context of quantum field theory (QFT) at temperature, chemical potential and finite size by the Gross-Nevel model in (2+1) dimensions, which description is made by a four-fermion interaction. The effects of temperature, chemical potential and finite size on the system are introduced by the formalism of QFT on toroidal topology, which is a generalization of Matsubara prescription where the temporal and spatial variables becomes compactified. We investigate these effects when an external parallel magnetic field applied to the planar fermion system resulting in an spin asymmetry, which is caracterized by a variation δµ on chemical potential. In this way, we obtain the effective potential in the leading order of the 1/N expansion (1 loop) with the aim of investigating the phase diagrams showing the regions of break and restoration of quiral symmetry from the model and how the external parameters influence the evolution of these diagrams.