Abstract Metamaterial research is an extremely important global activity that promises to change our lives in many different ways. These include making objects invisible and the dramatic impact of metamaterials upon energy medical sectors society. Behind all applications, however, lies business creating are not going be crippled by kind loss naturally heralded use resonant responses their construction. This review sets out some solutions management gain, coupled controlled nonlinear...

Abstract The nonlinear conductivity of 2D electron gas in graphene and 3D the narrow-gap n-InSb semiconductor has been simulated terahertz (THz) range by different methods including direct quantum approach, quasi-classical kinetics, quasi-relativistic hydrodynamics. These yield same results under temperatures ≤ 100 K when kinetic effective mass used hydrodynamics is equal to some nonzero that depends on concentration graphene. linear resonant dependencies complex are both from theory...

The simulations presented here are based on the observational data of lightning electric currents associated with eruption Hunga Tonga volcano in January 2022. response lithosphere (Earth)–atmosphere–ionosphere–magnetosphere system to unprecedented is theoretically investigated at low frequencies, including ultra frequency (ULF), extremely (ELF), and very (VLF) ranges. current source due near location has a wide-band spectrum determined this paper data-driven approach. monotonous VLF range...

Abstract An earthquake doublet occurred in Turkey on 6 February 2023, with propagating Rayleigh waves triggering perturbations the ionospheric total electron content (TEC) for both M 7.8 (EQ7.8) and 7.5 (EQ7.5). A discrepancy between velocities of TEC has been noted, but its causes remain unresolved previous studies. In this study, we calculated frequency‐dependent waves, considering their intrinsic dispersive characteristics. To retrieve TEC, utilized ground‐based Global Navigation...

The 2022 Hunga Tonga Volcano Eruption (HTVE) had unprecedented impacts on atmospheric space weather. It provided a clear example of how weather may be impacted by influences both “from above” (e.g. the solar wind, geo-magnetic storms) and below” powerful volcanoes, hurricanes, earthquakes). Manifestations geophysical effects from HTVE were an acoustic wave that circled Earth several times, formation strong ionospheric plasma bubbles depletion. An important...

Over the past 10 years, increasingly intensive studies of ionospheric plasma structures have been carried out using data from Low-Frequency Array for radio astronomy (LOFAR) telescope system. Recently more and attempts are taken to combine LOFAR with other monitoring techniques such as GNSS observations. detects scattering high-frequency (HF) (MHz) electromagnetic waves (EMW) on above-mentioned structures. Astrophysical sources EMWs may be, example, galaxies, supernovae remnants pulsars. The...

The first observation of spatiotemporal self-focusing spin waves is reported. experimental results are obtained for dipolar in yttrium-iron-garnet films by means a newly developed space- and time-resolved Brillouin light scattering technique. They demonstrate moving wave pulse two spatial dimensions, formation localized two-dimensional packets, the collapse which stopped dissipation. good qualitative agreement with numerical simulations.

An advanced space- and time-resolved Brillouin light-scattering technique is used to study diffraction of two-dimensional beams pulses dipolar spin waves excited by strip-line antennas in tangentially magnetized garnet films. The an effective tool for investigation spin-wave propagation with high spatial temporal resolution. Linear effects, such as the unidirectional excitation magnetostatic surface backward volume (BVMSW) two preferential directions due noncollinearity their phase group...

The topics here deal with some current progress in electromagnetic wave propagation a family of substances known as metamaterials. To begin with, it is discussed how pulse can develop leading edge that steepens and emphasised such self-steepening an important inclusion within metamaterial environment together Raman scattering third-order dispersion whenever very short pulses are being investigated. It the parameter highly metamaterial-driven compared to scattering, which associated...

Abstract Scattering and absorption of the H‐polarized plane wave by infinite grating flat graphene strips are considered in environment met most frequently—on or at surface a dielectric‐slab substrate. The full‐wave meshless code is based on analytical semi‐inversion using Riemann–Hilbert problem solution. This leads to Fredholm second‐kind matrix equation for Floquet harmonic amplitudes that guarantees convergence provides easy control computational error, which can be reduced machine...

The question of losses in metamaterials that are based upon magnetic resonances deriving from split-ring arrays is addressed through the use active inclusions designed diode arrays. A full discussion way which current-voltage characteristics deployed to produce gain given, and overall stability new material investigated a quantitative linked absolute convective instability. It shown instability associated with inclusion negative resistance devices can be avoided scheme approximately scalable...

We consider the scattering and absorption of E-polarized plane wave by infinite grating flat graphene strips lying on dielectric substrate. To build a trusted full-wave meshless algorithm, we cast problem to dual series equations perform its analytical regularization based use Inverse Discrete Fourier Transform. Then, reduces Fredholm 2nd-kind matrix equation for unknown Floquet harmonic amplitudes. Therefore, convergence resulting code is guaranteed theorems. Numerical experiments show that...

An observation of self-focusing dipolar spin waves in garnet film media is reported. In particular, we show that the quasistationary diffraction a finite-aperture spin-wave beam focusing medium leads to concentration wave power one focal point rather than along certain line (channel). The obtained results demonstrate wide applicability nonlinear study phenomena using an advanced combined microwave--Brillouin-light-scattering technique for two-dimensional mapping amplitudes.

We report a prediction of the optical effect apparently not discussed earlier. As known both from theory and experiment, gratings flat graphene strips lying on dielectric substrates display moderate-Q resonances strip plasmon modes in H-polarization case. In resonances, high reflectance absorbance are observed. These characteristics tunable with aid chemical potential, which controls plasmon-mode frequency. However, if this frequency coincides high-Q lattice-mode frequency, narrow-band...

Surface wave propagation at the interface between different types of gyrotropic materials and an isotropic negatively refracting medium, in which relative permittivity permeability are, simultaneously, negative is investigated. A general approach taken that embraces both gyroelectric gyromagnetic materials, permitting possibility operating either low GHz, THz or optical frequency regimes. The classical transverse Voigt configuration adopted a complete analysis non-reciprocal surface...

Collision properties of quasi-one-dimensional spin wave envelope solitons propagating in narrow ferrite film waveguides and two-dimensional self-focused packets (spin bullets) wide samples are studied both experimentally numerically. The experiments, performed by means a space- time-resolved Brillouin light scattering technique, have shown that retain their shapes after collisions, while bullets destroyed collisions. experiments also the introduction fixed phase shift between colliding leads...