Banca de DEFESA: FRANCISCO ALEXANDRE DE OLIVEIRA FEITOSA

Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
STUDENT : FRANCISCO ALEXANDRE DE OLIVEIRA FEITOSA
DATE: 22/10/2021
TIME: 09:00
LOCAL: Plataforma Google Meet
TITLE:

Propagation of electromagnetic waves in Kolakoski quasicrystal with graphene

KEY WORDS:

Electromagnetic waves; Quasicrystals; Kolakoski; Transmissivity

PAGES: 86
BIG AREA: Ciências Exatas e da Terra
AREA: Física
SUMMARY:

In this work, we simulate the incidence of electromagnetic waves in an one-dimensional photonic quasicrystal composed of multilayers following the Kolakoski sequence with graphene embedded at the interfaces. The system is formed by the juxtaposition of two blocks of different dielectric materials, A and B, with A being silicon dioxide, (SiO2) and B being titanium dioxide, (T iO2). Between the blocks A and B we insert layers of graphene. We used the Transfer Matrix Method, which simplifies the algebra involved, to perform the numerical calculation that generated the data analyzed in this work. Next, we present the objectives of this work: generate the necessary data to establish the transmission and reflection spectra, investigate the effects of the graphene monolayer and evaluate the effects of the quasiperiodicity on the physical behavior of the system. To do so, we impose variations on the following parameters of the system: angle of incidence, chemical potential of graphene, Kolakoski generation index and the type of electromagnetic propagation mode. The results obtained reveal that the presence of graphene reduces the transmissivity across the entire frequency range and also induces a band gap in the low frequency transmission. Furthermore, we observe that the band gap produced by graphene is omnidirectional and that its thickness increases with the increase of graphene’s chemical potential, which can be adjusted by the value of the electrical voltage. Furthermore, we identified frequency ranges that present a Bragg gap

BANKING MEMBERS:
Externo à Instituição - CARLOS HUMBERTO OLIVEIRA COSTA - UFC
Interno - 1345774 - CLAUDIONOR GOMES BEZERRA
Interno - 1519258 - DORY HELIO AIRES DE LIMA ANSELMO
Interno - 1354851 - MANOEL SILVA DE VASCONCELOS
Externo à Instituição - SERGIO ANDRÉ FONTES AZEVEDO - UFPB
Externo à Instituição - VAMBERTO DIAS DE MELLO - UERN