An effective model for strongly correlated electrons

• Ano de defesa: 2019
• Autor(a) principal: Xavier, Hernán Guillermo Bueno
• Orientador(a): Ferraz Filho, Alvaro
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Programa de Pós-Graduação: PROGRAMA DE PÓS-GRADUAÇÃO EM FÍSICA
• País: Brasil
• Palavras-chave em Português: Elétrons fortemente correlacionados; Modelo t-J; Cupratos de alta-Tc; Teoria de campos efetiva
• Área do conhecimento CNPq: CNPQ::CIENCIAS EXATAS E DA TERRA::FISICA
• Link de acesso: https://repositorio.ufrn.br/jspui/handle/123456789/27250

In this work we examine an alternative effective formulation for the t-J model which is believed to capture the essential physics behind the underdoped regime of the highTc cuprates. After recasting the original problem into this representation, we check the consistency of the procedure and discuss some physical consequences of such a representation, including, the crossover between the regimes of small and large Fermi surfaces which is observed experimentally. We then explore the possiblity of constructing a path integral representation of the partition function of the the t-J model by departing from the formulation presented. Finally, we use the latter formalism to derive a continuum effective field theory in (2 + 1) spacetime dimensions which features small hole-like pockets near the nodal regions of the Brillouin zone along with an unconventional mechanism for superconductivity.