Navegando por Autor "DMITRIEV, Victor Alexandrovich"

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Acesso aberto (Open Access)
Analysis of electronic structure of boron nitride nanotubes with different positions of intrinsic impurities
(2014-12) GOMES, Fernando Antonio Pinheiro; DMITRIEV, Victor Alexandrovich; NASCIMENTO, Clerisson Monte do
The pristine boron nitride nanotubes have a large direct band gap around 5 eV. This band gap can be engineered by doping. We investigate electronic structure of the doped hexagonal boron nitride (5,5) nanotubes using the linearized augmented cylindrical wave method. In particular, this work focuses on systematical study of the band gap and the density of states around the Fermi-level when the nanotubes are doped by intrinsic impurities of two substitutional boron atoms in a super cell and a comparative analysis of the relative stability of three structures studied here. This corresponds to 3.3% of impurity concentration. We calculate 29 configurations of the nanotubes with different positions of the intrinsic impurities in the nanotube. The band gap and density of states around the Fermi level show strong dependence on the relative positions of the impurity atoms. The two defect sub bands called D∏(B) appear in the band gap of the pristine nanotube. The doped nanotubes possess p-type semiconductor properties with the band gap of 1.3-1.9 eV.
Acesso aberto (Open Access)
Analysis of modified bowtie nanoantennas in the excitation and emission regimes
(2011-06) COSTA, Karlo Queiroz da; DMITRIEV, Victor Alexandrovich
In this work, we analyze modified bowtie nanoantennas with polynomial sides in the excitation and emission regimes. In the excitation regime, the antennas are illuminated by an incident plane wave, and in the emission regime, the excitation is fulfilled by infinitesimal electric dipole positioned in the gap of the nanoantennas. Several antennas with different sizes and polynomial order were numerically analyzed by method of moments. The results show that these novel antennas possess a controllable resonance by the polynomial order and good characteristics of near field enhancement and confinement for applications in enhancement of spontaneous emission of a single molecule.
Acesso aberto (Open Access)
Comparative analysis of circular and triangular gold nanodisks for field enhancement applications
(2010-12) COSTA, Karlo Queiroz da; DMITRIEV, Victor Alexandrovich
In this paper, we present a quantitative comparison of circular and triangular gold nanodisks with the same length and thickness. The method of moments is used to solve numerically the scattering problem. With this model, we investigate the spatial near field distribution, spectral response, far field diagrams, and bandwidth wavelength of these particles. Our results show that the resonant wavelength and the near field enhancement and confinement of the triangular particle are larger than those for the circular particle, but the resonance bandwidth and scattering cross section of the triangular particle are smaller.
Acesso aberto (Open Access)
Development of computational 3D MoM algorithm for nanoplasmonics
(2013-12) SOUZA, Nadson Welkson Pereira de; COSTA, Karlo Queiroz da; DMITRIEV, Victor Alexandrovich
In this paper, we present an algorithm for full-wave electromagnetic analysis of nanoplasmonic structures. We use the three-dimensional Method of Moments to solve the electric field integral equation. The computational algorithm is developed in the language C. As examples of application of the code, the problems of scattering from a nanosphere and a rectangular nanorod are analyzed. The calculated characteristics are the near field distribution and the spectral response of these nanoparticles. The convergence of the method for different discretization sizes is also discussed.
Acesso aberto (Open Access)
Microwave switchable frequency selective surface with high quality factor resonance and low polarization sensitivity
(2012-12) KAWAKATSU, Marcelo Nobuyuki; DMITRIEV, Victor Alexandrovich
We present a microwave switchable frequency selective surface with high quality factor transmission resonance. The high quality resonance is achieved by excitation of the trapped-mode in array with two concentric metal rings in a cell on a silicon substrate. Optical activation of the silicon substrate permits to switch off the transmission band.
Acesso aberto (Open Access)
Nanoelectronic Devices Based on Carbon Nanotubes
(Universidade Federal do Pará, 2015-03) DMITRIEV, Victor Alexandrovich; GOMES, Fernando Antonio Pinheiro; NASCIMENTO, Clerisson Monte do
Carbon nanotubes are possible building blocks in the development of new generation of electronic devices. The carbon nanotubes allow one fabrication of devices using nanometric scales. They can be used in projects of a wide range of electronic and optoelectronic components such as diodes, transistors and interconnection elements, among others. This paper presents the state-of-the-art of this area, emphasizing the influence of quantum effects on the characteristics of such components.
Acesso aberto (Open Access)
Resonant properties, of modified triangular plasmonic nanoparticles with higher field concentration
(2013-12) COSTA, Karlo Queiroz da; DMITRIEV, Victor Alexandrovich
In this paper, we present an analysis of the resonant response of modified triangular metallic nanoparticles with polynomial sides. The particles are illuminated by an incident plane wave and the method of moments is used to solve numerically the electromagnetic scattering problem. We investigate spectral response and near field distribution in function of the length and polynomial order of the nanoparticles. Our results show that in the analyzed wavelength range (0.5-1.8) µm these particles possess smaller number of resonances and their resonant wavelengths, near field enhancement and field confinement are higher than those of the conventional triangular particle with linear sides.
Acesso aberto (Open Access)
Theoretical study of plasmonically induced transparency effect in arrays of graphene-based double disk resonators
(Sociedade Brasileira de Micro-ondas e Optoeletrônica, 2019-03) PORTELA, Gianni Masaki Tanaka; DMITRIEV, Victor Alexandrovich; OLIVEIRA, Cristiano Braga de; CASTRO, Wagner Ormanes Palheta
In this paper, we consider coupled disk-shaped resonators separated by a thin dielectric substrate that can be used as frequency-tunable filters or as electromagnetic switches in the terahertz frequency band. The two disks are electromagnetically coupled and resonate with dipole plasmonic modes. By using a Temporal Coupled-Mode Theory based approach, we show how to analytically calculate the frequency response of such structures.The analytical results are in good agreement with those obtained from computational simulations based on the finite element method.