Influence of doping on superconducting states of single-layer graphene.

• Ano de defesa: 2021
• Autor(a) principal: Pinto, Yan Matheus Colares
• Outros Autores: http://lattes.cnpq.br/0587684254993109
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: eng
• Instituição de defesa: Universidade Federal do Amazonas; Instituto de Ciências Exatas; Brasil; UFAM; Programa de Pós-graduação em Física
• Palavras-chave em Português: Supercondutividade; CIENCIAS EXATAS E DA TERRA; Graphene; Superconductivity; Order parameter
• Link de acesso: https://tede.ufam.edu.br/handle/tede/8866

An increase in the number of studies involving graphene has been notable in the recent decades, mainly due its two-dimensional structure and also for the varied applications in technological devices. Superconductivity has been observed in different materials when placed under very-low temperatures, which motivated us to the study the different phases of the superconducting states in the honeycomb lattice structure of graphene. In this work we consider pure two-dimensional single-layer graphene on a honeycomb lattice. A tight-binding model of the electrons and their energy bands in the first Brillouin zone described by the linear dispersion of the Dirac fermions is used to describe the graphene in its pure form. We study the superconducting phases of the graphene using a mean field theory to calculate the temperature dependencies of the order parameters and also the specific heat of the system below the critical temperature. Conciling this states of matter applied to graphene and considering doping effects we analized the phases states for attractive electron-electron interactions energies. We get in addition to the usual s-wave, an exotic possibility appears in the form of a symmetric p+ip wave due to the symmetry structure around the Dirac points. The coexistence of the above two phases has been of utmost importance for our study. Hence the characteristic graphs of the order parameter and specific heat in the variation of the chemical potential are studied.