For single-walled carbon nanotubes(SWCNTs)with a length of 1-50μm,the surface plasmon-polariton(SPP)resonance is within the terahertz frequency range;therefore,SWCNT lattices can be used to design frequency-selective...For single-walled carbon nanotubes(SWCNTs)with a length of 1-50μm,the surface plasmon-polariton(SPP)resonance is within the terahertz frequency range;therefore,SWCNT lattices can be used to design frequency-selective surface(FSS).A numerical model of electromagnetic wave diffraction on a two-dimensional periodic SWCNT lattice can be described by an integro-differential equation of the second-order with respect to the surface current along SWCNT.The equation can be solved by the Bubnov-Galerkin method.Frequency dependence of reflecting and transmitting electromagnetic waves for FSSs near the SPP resonance is studied numerically.It is shown that the resonances are within the lowerfrequency part of the terahertz range.We also estimate the relaxa-tion frequency of an individual SWCNT and demonstrate the applic-ability of the Kubo formula for graphene conductivity to array of strips similar in size to SWCNTs under consideration.展开更多
The frequency dependence of scattering parameters of interdigital surface acoustic wave transducers placed on ferroelectric barium titanate(BaTiO_(3))epitaxial film in c-phase coated over magnesium oxide has been stud...The frequency dependence of scattering parameters of interdigital surface acoustic wave transducers placed on ferroelectric barium titanate(BaTiO_(3))epitaxial film in c-phase coated over magnesium oxide has been studied using the finite-element method(FEM)approach along with the perfectly matched layer(PML)technique.The interdigital transducer which has a comb-like structure with aluminum electrodes excites the mechanical wave.The distance between the fingers allows tuning the frequency properties of the wave propagation.The magnesium oxide is taken as the substrate.The two-dimensional model of two-port surface acoustic wave filter is created to calculate scattering parameters and to show how to design the fixture in COMSOL_(TM).Some practical computational challenges of finite element modeling of SAW devices in COMSOL_(TM)are shown.The effect of lattice misfit strain on acoustic properties of heterostructures of BaTiO_(3)epitaxial film in c-phase at room temperature is discussed in present article for two lowfrequency surface acoustic resonances.展开更多
基金Russian Foundation for Basic Research(RFBR),project number 21-52-15034。
文摘For single-walled carbon nanotubes(SWCNTs)with a length of 1-50μm,the surface plasmon-polariton(SPP)resonance is within the terahertz frequency range;therefore,SWCNT lattices can be used to design frequency-selective surface(FSS).A numerical model of electromagnetic wave diffraction on a two-dimensional periodic SWCNT lattice can be described by an integro-differential equation of the second-order with respect to the surface current along SWCNT.The equation can be solved by the Bubnov-Galerkin method.Frequency dependence of reflecting and transmitting electromagnetic waves for FSSs near the SPP resonance is studied numerically.It is shown that the resonances are within the lowerfrequency part of the terahertz range.We also estimate the relaxa-tion frequency of an individual SWCNT and demonstrate the applic-ability of the Kubo formula for graphene conductivity to array of strips similar in size to SWCNTs under consideration.
基金This work was supported by the the Russian Science Foundation[14-19-01676].
文摘The frequency dependence of scattering parameters of interdigital surface acoustic wave transducers placed on ferroelectric barium titanate(BaTiO_(3))epitaxial film in c-phase coated over magnesium oxide has been studied using the finite-element method(FEM)approach along with the perfectly matched layer(PML)technique.The interdigital transducer which has a comb-like structure with aluminum electrodes excites the mechanical wave.The distance between the fingers allows tuning the frequency properties of the wave propagation.The magnesium oxide is taken as the substrate.The two-dimensional model of two-port surface acoustic wave filter is created to calculate scattering parameters and to show how to design the fixture in COMSOL_(TM).Some practical computational challenges of finite element modeling of SAW devices in COMSOL_(TM)are shown.The effect of lattice misfit strain on acoustic properties of heterostructures of BaTiO_(3)epitaxial film in c-phase at room temperature is discussed in present article for two lowfrequency surface acoustic resonances.
