Superconductivity in the 2D attractive Hubbard model within a functional field-theorical RG

• Autor(a) principal: Ferraz Filho, Álvaro
• Data de Publicação: 2011
• Outros Autores: Correa, Eberth, Freire, Hermann
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Institucional da UFRN
• Texto Completo: https://repositorio.ufrn.br/jspui/handle/123456789/28810
• topic: Renormalization group; Attractive Hubbard model; superconductivity

We apply the functional field-theoretical renormalization group methodology up to twoloop order to the 2D attractive Hubbard model for weak bare interaction. Since the momentum-resolved quasiparticle weight ZΛ(p) is always close to unity in the RG flow, higher-order quantum fluctuations do not affect crucially the low-energy dynamics in this case. As a result, we observe a s-wave singlet superconducting quasi-long-range order phase as a function of doping in good agreement with other numerical methods. To assess the role played by the fluctuations we compare the critical temperature Tc in which the quasi-long-range superconducting order phase takes place within our approach with mean-field theory and quantum Monte Carlo results.