Banca de DEFESA: JOSÉ ROBERTO DA SILVA

Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
STUDENT : JOSÉ ROBERTO DA SILVA
DATE: 29/06/2022
TIME: 10:00
LOCAL: Plataforma Google Meet
TITLE:

Electronic transport in quasi-periodic nanostrutrures

KEY WORDS:

Electronic transport; quais-periodic perturbation; Fibonacci; recursive Green functions

PAGES: 174
BIG AREA: Ciências Exatas e da Terra
AREA: Física
SUMMARY:

In this work the electronics and transport properties of Fibonacci superlattice formed by nanostructures with quasi-periodic perturbations are investigated. The calculations of transport are based in the recursive method of Green’s function (RGF) within of the ap- proximation tight binding (TB). In our calculations we explore neighbors first and second interaction. In ours models we try to investigate linear, double chain and graphene nano- ribbons. Two types of perturbations are investigated. The first consist in quasi-periodic perturbation by substitutional doping (PQD). The second is featured by modulation of the Fermi velocity (MVF). In both the cases the perturbations are achieved by replication of pure and defectives blocks in the central part of the structure. Ours results show that the replication of the blocks in the scattering center reduces substantially the conduc- tance, producing a series of dips that are inducing to gaps in determined energy level. This behavior is characteristic of systems in strongly localized regime. In some situations we demonstrate that theses gaps are induced by a Anderson localization regime. This effect occurs due to interference and to electronic confinement that leads to quasi-bound states. Theses states are clearly observed in the calculation of the local states density (LDOS). Besides that, we show that the modulation these perturbations provoke effects different in armchair and zigzag nanoribbons. We show too that the transport properties can to be tuned continuously by variation quasiperiodic of the length of the central part. Additionally, the results obtained in this work can to provide a new approach for the study of the control of the electronic response of one-dimensional nanostructures.

BANKING MEMBERS:
Externo à Instituição - JONAS ROMERO FONSECA DE LIMA - UFRPE
Externo à Instituição - CLAUDIA GOMES DA ROCHA - UofC
Externo à Instituição - ANDERSON LUIZ DA ROCHA BARBOSA - UFRPE
Interno - 2411793 - LEONARDO DANTAS MACHADO
Presidente - 1457464 - LUIZ FELIPE CAVALCANTI PEREIRA
Interna - 1675199 - SUZANA NOBREGA DE MEDEIROS