Estudo de propagação de plásmons de superfície em grafeno e realização de portas lógicas OR, AND e XOR

• Ano de defesa: 2017
• Autor(a) principal: Aguiar, Antônio Francisco
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Palavras-chave em Português: Teleinformática; Grafeno; Logical ports; Graph; Nanofotônica; Plásmons; Plasmonic
• Link de acesso: http://www.repositorio.ufc.br/handle/riufc/37240

This work aims to study devices based on graphene in order to obtain logic gates. The model is based on graphene immersed nanofits in dielectric substrate, constructed in such a way that there is coupling of surface plasmon polaritons (SPPs) between sheets of graphene. An interferometric device was proposed as a function of the conductivity of the graphene nanofits and of the geometric dimensions. It was made a numerical analysis of the behavior of the SPPs modes in relation to their chemical potential, as well as a scan of geometric parameters of the device in order to obtain the necessary configurations to perform the logical AND/OR/XOR functions for OOK modulation. The results showed that the lowest extinction level obtained at the proposed gates outputs, referring to the ON state (logical bit 1), was - 4.75 dB. While the OFF state (logical bit 0), the highest extinction level was -11.29 dB. For the OR gate presented higher transmission and coupling efficiency, around -4 dB, for a chemical potential of 0.229 eV for the graphene embedded in a silica substrate with relative permittivity of 2.1. In the AND gate the transmission performance was approximately -5 dB in the coupling region, when the two input channels are ON. This proves the efficiency of graphene plasmon-based logic gates with a minimum average extinction ratio between the 6 dB OFF/ON states for all logic function types.