bluuebunny/crossref_metadata_2025_split huggingface dataset:
Numerical simulation of wave propagation and plasma response excited in field-reversed configuration plasma
Authors: Urano Takahiro , Takahashi Toshiki , Asai Tomohiko , Okada Shigefumi 
Published: November 2021

Abstract
A hybrid simulation (a model that treats ions as particles and electrons as fluid) is performed to analyse the propagation of waves excited in the field-reversed configuration plasma and the resulting plasma response. The current of the wave excitation antenna changes in a sine wave, and its frequency is set so that it has an ion cyclotron resonance point inside the separatrix. When the antenna current is maximum, a magnetic field with a magnitude of 40% of the external magnetic field is created on the separatrix. A toroidal magnetic field is excited in the plasma by applying waves. The observed propagation velocity of the toroidal magnetic field is comparable with the shear Alfvén wave outside the separatrix, and is on the same order within the separatrix. This result has a tendency similar to the propagation velocity outside the separatrix reported in the wave experiment in the past FIX machine. The simulation results also show that when the excited magnetic field propagates in the axial direction, the separatrix is compressed or expanded, and the high-density region of the ions formed thereby moves in the axial direction. In addition, the excited magnetic energy is rapidly decreased near the position where the velocities of the shear Alfvén wave and the ion sound wave are equal (local beta value is 0.88). It is found that the decay of the excited magnetic energy occurred at a point outside the ion cyclotron resonance point. This suggests that the compression and expansion of the plasma is caused while maintaining the quasi-equilibrium state according to the change in the external magnetic pressure.
Investigation of directivity of the nanoantenna by its inherent resonant states
Authors: Agrahari Rajan , Shamkhi Hadi K. 
Published: November 2021

Abstract
We present a quasinormal mode (QNM) approach for modeling the nanoantenna and describe the response of localized dielectric cylinder resonators. The inherent resonant states of the dielectric cylinder nanocavity are investigated for modified and reduced geometrical symmetry. We find some modes contributing mainly to the directivity and have a high-quality factor. The variation of the eigenmodes with cylinder height and substrate refractive index has also been investigated.
Highly Directive All-Dielectric Nanoantenna
Authors: Agrahari Rajan , Shamkhi Hadi K. 
Published: November 2021

Abstract
A highly directive dielectric nanoantenna in an integrated chip may enable faster communication as their low losses and small size overcome the limitation of temperature enhancement and low data transfer rate. We optimize nanoantenna consist of Si-nanoblock in the near-infrared region to efficiently transfer a point dipole light to a highly directive light in the far-field region. We engineer the intrinsic electric and magnetic resonances of a Si-block nanoantenna by modifying and reducing its geometrical symmetry. We realize a pronounced enhancement of directivity by systematically inducing perturbation in the Silicon block so that both its reflection and rotational symmetries are broken. Finally, we retain the traditional method to increase resonance’s coupling to outer space by introducing substrate with an increasing refractive index. We find that the directivity has boosted rapidly.
Wide-angle Reconfigurable Refraction by Silicon Fourier Metasurfaces
Authors: Antonov A A , Gorkunov M V 
Published: November 2021

Abstract
We design metasurfaces based on silicon films with smooth relief described by several Fourier harmonics and study their ability to redirect the refracted light over a wide angular range controlled by subtle variations of the optical setup. We use semi-analytical approach based on the Rayleigh hypothesis as well as full-scale numerical solutions to optimize the relief shape. To illustrate the reconfigurability potential, we design metasurfaces efficiently redirecting the refracted light from 83° to −73° with respect to the normal, when the angle of incidence is varied from 0° to 2°, and from 80° to −74°, when the substrate permittivity is altered from 2.3 to 2.2.
Effective electrodynamical parameters and microwave heating of radially heterogeneous pellets containing EAF dust and biochar
Authors: Anzulevich Anton P , Butko Leonid N , Pavlov Dmitry A , Kalganov Dmitry A , Tolkachev Valentin A , Anzulevich Svetlana N , Buchelnikov Vasiliy D , Moiseev Sergey G , Peng Zhiwei 
Published: November 2021

Abstract
In this work, we investigated the effect of microwave radiation with radially heterogeneous pellets consisting of electric arc furnace (EAF) dust and biochar. We reviewed the possible content of EAF dust in terms of permittivity and permeability of its components and calculated effective permittivity and permeability of EAF dust by an effective medium approach. Using obtained values we calculated dependencies of effective permittivity and permeability of EAF dust - biochar composite mixture on the volume fraction of EAF dust and conductivity of biochar. Taking into account these dependencies we simulated electromagnetic field and temperature distribution within pellet with a radial dependency of volume fraction of EAF dust and effective permittivity correspondingly.
ITO-free Perovskite Light-Emitting Electrochemical Cell
Authors: Baeva M , Gets D , Bodyago E , Mozharov A , Neplokh V , Nasibulin A , Mukhin I , Makarov S 
Published: November 2021

Abstract
Since Complementary metal–oxide–semiconductor technology is the conventional technology for micro- and optoelectronics, integration of emerging materials, such as halide perovskites, into the process is an important branch of perovskite technologies development. In this regard ITO free device research becomes increasingly important. The Perovskite Light-Emitting electrochemical cells are a promising alternative to conventional Perovskite Light Emitting Diodes. In this work we demonstrate green (λEL = 523 nm) CsPbBr3 Perovskite Light-Emitting electrochemical cells with luminescence intensity of 50 kd/m2 integrated with Si++(111) substrate.
High-Q two-groove resonator for all-dielectric Bloch surface wave platform
Authors: Bezus E A , Kadomina E A , Bykov D A , Morozov A A , Doskolovich L L 
Published: November 2021

Abstract
We propose a simple integrated resonant structure for the Bloch surface wave platform, which consists of two subwavelength grooves patterned on the surface of a one-dimensional dielectric photonic crystal. We demonstrate that the investigated structure can operate in a parasitic-scattering-free regime and, in this case, provide unity transmittance and zero reflectance at resonance conditions associated with the excitation of a leaky mode of the structure localized at the central ridge formed by the grooves. The proposed structure may find application in integrated photonic devices for optical filtering and analog optical computing.
Are there bound states in the continuum in a dielectric ring?
Authors: Bochek D V , Solodovchenko N S , Samusev K B , Limonov M F 
Published: November 2021

Abstract
Trapping and confining electromagnetic waves is important in both basic research and a variety of applications. For these purposes, various physical mechanisms are exploited including bound states in the continuum, which have been actively investigated recently. Bound states in the continuum have been observed in various objects consisting of both one and a number of dielectric structures. In particular, these photonic states were observed in high-contrast dielectric cylinders in the regime of strong eigenmode coupling, which leads to destructive interference in the far-field zone. In this article, we present the results of a study of bound states in a continuum in a dielectric ring, i.e. cylinder with coaxial air hole. The dependence of the quality factor Q on the normalized diameter of the hole is discussed.
Creation of an MRI phantom based on super-paramagnetic nanoparticles of iron oxide (SPIO) for standardization of the conversion of T2 * values in the concentration of iron in the liver
Authors: Bulanov P.A. , Nazarova E.E. , Menshchikov P.E. , Kupriyanov D.A , Tereshchenko G.V. , Novichkova G.A. 
Published: November 2021

Abstract
In this study the standardization method for T2* maps acquisition on various MR scanners (3T and 1.5T) is proposed. The reproducibility of the obtained T2* values is realized through the MR-compatible phantom containing paramagnetic complex iron oxide nanoparticles. The repeatability of measurements results has shown that the created phantom retains all the required characteristics (homogeneity, stability of concentrations and manifested paramagnetic properties) over a long period of time. The application of standardized T2* values allows to use previously received T2*, [ms] to iron concentrations in the dry substance of the liver (LIC), [mg/ml] conversion formulas for accurate, fast and non-invasive MRI diagnostics of liver iron overload.
Elastic Trapped Modes in Solid Acoustic Resonators of Various Shapes
Authors: Deriy Ilya , Toftul Ivan , Petrov Mihail , Bogdanov Andrey 
Published: November 2021

Abstract
Resonators are one of the main building blocks of many acoustic, photonic, and microwave devices such as metasurfaces, sensing devices, antennas, and many more. One of the main properties of any resonator, which also determines the properties of the structure, based on the resonator, is the quality (Q) factor. Q-factor of the resonator is limited due to material and radiative losses. In this paper, we propose the existence of modes of solid resonators, immersed in a nonviscious fluid, which are non-radiative, and therefore, their Q-factor is limited only by material losses.
Finding exceptional points in realistic systems using full-wave simulations
Authors: Dmitriev Alexey A , Rybin Mikhail V 
Published: November 2021

Abstract
Here, we present an approach to finding exceptional points using the finite-element method. Using this method, we demonstrated exceptional points in 2D dimers of infinite cylinders and infinite parallelepipeds. The results agree well with the analytical coupled-dipole model, however a deviation due to the contribution of higher multipoles, is present. Our approach can be applied to three-dimensional particles as well.
Cellular SERS structures for non-invasive study of living cells
Authors: Doroshina N V , Ushkov A A , Brazhe N A , Gorin D A , Mokrousov M D , Yakubovsky D I , Kapitanova O O , Voronov A A , Arsenin A V , Volkov V S , Novikov S M 
Published: November 2021

Abstract
Surface-enhanced Raman spectroscopy (SERS) is a potent and highly selective tool to chemically identify and determine the structure of molecules and materials. However, the large biomolecules and living cells are still difficult to study using modern SERS-substrates. Here we present a new approach to the geometry of the surface of plasmon nanostructures (cellular surfaces), which makes it possible to efficiently work with volumetric objects as cells or organelles. We use the scanning Raman microscope to map the SERS from the specially prepared microcapsules formed with a Layer-by-Layer deposition method and with built-in Raman tags (Indocyanine green). It demonstrated the possibility to detect SERS signal from Indocyanine green in microcapsules located in cavities, while the signal from the Raman dye in microcapsules located on a flat surface is not detected. The obtained results can be useful in biosensors applications.
Integrated high-contrast diffraction gratings for surface electromagnetic waves
Authors: Doskolovich L L , Bezus E A , Bykov D A 
Published: November 2021

Abstract
We propose and theoretically and numerically investigate integrated high-contrast diffraction gratings for surface electromagnetic waves. We consider two platforms for the on-chip gratings: surface plasmon-polaritons propagating along metal-dielectric interfaces and Bloch surface waves propagating along interfaces of photonic crystals. We demonstrate that the optical properties of the studied integrated gratings are qualitatively close to the ones of the conventional high-contrast diffraction gratings. If the “parasitic” out-of-plane scattering is suppressed, the reflectance and transmittance of the on-chip gratings are not only qualitatively, but also quantitatively close to the corresponding values of the conventional “free-space” gratings. The obtained results may find application in novel integrated optical circuits.
Weak plasmon modes in periodic structures for terahertz detection and amplification
Authors: Fateev D V , Polischuk O V , Morozov M Yu , Mashinsky K V , Moiseenko I M , Popov V V 
Published: November 2021

Abstract
Weak plasmon modes in periodic structures with a two-dimensional electron gas without an inversion center are studied theoretically. The asymmetry of the electric field and Fourier harmonics of weak plasmon modes can lead to the excitation of a travelling plasmon by an electromagnetic wave normally incident on the structure and to the appearance of nonlinear effects leading to the rectification of the incident radiation. The low radiation damping of weak plasmon modes can be used to increase the efficiency of terahertz plasmon amplifiers.
High-Q states in acoustic apple-shaped resonators
Authors: Igoshin Vladimir , Nikitina Anastasia , Tsimokha Mariia , Toftul Ivan , Petrov Mihail , Frizyuk Kristina 
Published: November 2021

Abstract
Apples play a significant role in our culture in various points of human history: starting from Adam and Eve, going on with Judgement of Paris, it also touches such great minds as Sir Isaac Newton and Alan Turing. Beyond that apples are still extremely relevant today due to Steve Jobs. In this work we study high quality (high-Q) resonant states of apple-shaped resonators. We have found that quasi bound states in continuum (quasi-BICs) are possible in the linear acoustic domain. We show that quasi-BICs are of Friedrich-Wintgen type, i.e. accompanied with avoided crossings while elongating or shrinking the apple-shaped resonator. Finally, we build a concise theory based on the group theory approach utilizing Wigner’s theorem. We illustrate that only the resonator symmetry plays major role, but not particular resonator’s shape.
Subwavelength probing of surface plasmons in magnetoplasmonic crystals
Authors: Frolov Aleksandr Yu , Verellen Niels , Moshchalkov Victor V , Fedyanin Andrey A 
Published: November 2021

Abstract
In this work, we report on near-field studying of propagating surface plasmons (SPs) in one-dimensional magnetoplasmonic crystals (MPCs) by aperture type scanning near-field optical microscopy (SNOM). Optical near-field around the aperture probe is used to drive SPs in the MPC locally. The SNOM signal represents the scattered intensity caused by the interaction of the SNOM probe near-field with the MPC. Scanning the MPC surface with polarization resolving of the scattered radiation shows decreasing of the intensity due to the SP excitation. The observed polarization dependence of the scattered SNOM signal is associated with the selective coupling of the near-field components of the SNOM probe with SPs. Finite-difference time-domain simulations reproduce the experimental SNOM signal. It is shown the excitation of SPs with symmetric (even parity) field distribution, which is forbidden for plane wave source at normal incidence.
Principal Component Analysis Applied to Gradient Fields in Band Gap Optimization Problems for Metamaterials
Authors: Gnecco Giorgio , Bacigalupo Andrea , Fantoni Francesca , Selvi Daniela 
Published: November 2021

Abstract
A promising technique for the spectral design of acoustic metamaterials is based on the formulation of suitable constrained nonlinear optimization problems. Unfortunately, the straightforward application of classical gradient-based iterative optimization algorithms to the numerical solution of such problems is typically highly demanding, due to the complexity of the underlying physical models. Nevertheless, supervised machine learning techniques can reduce such a computational effort, e.g., by replacing the original objective functions of such optimization problems with more-easily computable approximations. In this framework, the present article describes the application of a related unsupervised machine learning technique, namely, principal component analysis, to approximate the gradient of the objective function of a band gap optimization problem for an acoustic metamaterial, with the aim of making the successive application of a gradient-based iterative optimization algorithm faster. Numerical results show the effectiveness of the proposed method.
Dependence of the nonlinear optical response of CdSe nanoscrolls on coating with oleic or acetic acid
Authors: Golinskaya A D , Smirnov A M , Mantsevich V N , Kozlova M V , Kurtina D A , Vasiliev R B , Dneprovskii V S 
Published: November 2021

Abstract
The photoluminescence and nonlinear transmission of atomically thin population of colloidal CdSe rolled-up nanosheets were investigated at the one-photon stationary excitations of excitons by the third harmonic of Nd3+:YAP laser pulses. It was revealed that the nonlinear optical response of the nanoscrolls is strongly influenced by multiwalled rolled-up structure. The broadening of exciton band and the red shift of the photoluminescence were observed and explained by coupling effect within the folded scroll-layers.
Exceptional points in composite structures consisting of two dielectric diffraction gratings with Lorentzian line shape
Authors: Golovastikov Nikita , Bykov Dmitry , Doskolovich Leonid 
Published: November 2021

Abstract
Using scattering matrix formalism we derive analytical expressions for the eigenmodes of a composite structure consisting of two dielectric diffraction gratings with Lorentzian profile in reflection. Analyzing these expressions we prove formation of two distinct pairs of exceptional points, provide analytical approximations for their coordinates and by rigorous simulation demonstrate eigenmodes interchange as a result of encircling said exceptional points.
Single photon sources based on HPHT nanodiamonds
Authors: Kurochkin N S , Eliseev S P , Sychev V V , Gritsienko A V , Gorelik V S , Vitukhnovsky A G 
Published: November 2021

Abstract
Color centers in nanodiamonds are promising candidates for the creation of high-speed sources of single photons without blinking and degradation. Color centers in HPHT nanodiamonds have been investigated. The luminescence decay curves of color centers have been measured. Second order correlation functions were measured for nanodiamonds with sizes from 50 nm to 250 nm. Conclusions about the energy structure of color centers were made based on the correlation functions.
Mechanical deformation of atomically thin layers during stamp transfer
Authors: Ivanova Tatiana V , Permyakov Dmitry , Khestanova Ekaterina 
Published: November 2021

Abstract
The way transition metal dichalcogenide (TMD) strains during its transfer from one substrate to another is very interesting and holds a special place in the creation of heterostructures. In our work we observe the spectrum of photoluminescence in TMD during the transfer. For this we use a specially designed transfer system with inverted geometry. During transfer we observe a modification of exciton photoluminescence linewidth and resonance shift in atomically thin layers of TMD. We believe that our results lay grounds for the future work on the assessment of the atomically thin layer inhomogeneity introduced by the typical mechanical transfer.
Linear optical properties of HKUST-1 metal-organic framework: Effect of the crystal size and synthetic approach
Authors: Kenzhebayeva Yuliya A. , Bachinin Semyon , Gilemkhanova Venera , Milichko Valentin A. 
Published: November 2021

Abstract
We evaluated the change in the transmission and reflection spectra of single rhombic dodecahedron nanocrystals of the metal organic frameworks HKUST-1 with and without effect of near infrared laser radiation. The analysis of commercial and synthesized in the laboratory compounds was made through the optical transmittance and reflectance spectroscopy. Moreover, electronic microscopy and light scattering on the microcrystals was also utilized for revealing the size dependent colour. Such studies may find new application for MOF nanocrystals, as well as gain additional information about their usage for biological purposes or in computer sensing.
Light-induced electron pairing in two-dimensional systems
Authors: Kibis O. V. , Boev M. V. , Kovalev V. M. 
Published: November 2021

Abstract
The mechanism of electron pairing induced by a circularly polarized off-resonant electromagnetic field is suggested and examined theoretically for various two-dimensional (2D) nanostructures. Particularly, it is demonstrated that such a pairing can exist in 2D systems containing charge carriers with different effective masses. As a result of the pairing, the optically induced hybrid Bose-Fermy system appears. The elementary excitation in the system are analyzed and the possible Bose-Einstein condensation of the paired electrons and the related light-induced superconductivity are discussed.
Optomechanical interaction between single-walled carbon nanotubes of various structures
Authors: Kislov D , Kushchenko O , Shalin A S 
Published: November 2021

Abstract
We consider optomechanical interaction in an asymmetric structure of a carbon nanotubes dimer of different orientations and/or different atomic structures in the field of a plane wave or a focused Gaussian beam. Here we show that optical coupling in such the system can lead to nonreciprocal interactions between the constituents. We demonstrate that a non-conservative force is applied to the center of mass of an optically coupled nanotube dimer, resulting in an unexpected lateral action. The sign and magnitude of this force depend on abrupt phase transitions in the properties of the asymmetric dimer.
Continuous-Flow Synthesis of Perovskite Particles for Optical Application
Authors: Koryakina Irina , Bikmetova S , Arabuli K , Evstrapov A , Pushkarev A , Makarov S , Zyuzin M V 
Published: November 2021

Abstract
Conventional chemical synthesis methods for nanomaterials fabrication do not always provide precise reproducible synthesis with controllable physicochemical parameters. A better control over the resultant properties of nanomaterials can be achieved by scaling down the synthesis approach to the microlevel. This can be realized by means of microfluidics. In this work, a microfluidic approach is applied for the controllable synthesis of perovskite particles with defined cubic morphology. The structural characterization of perovskite particles is performed using scanning electron microscopy and X-ray diffraction. All the synthesized particles demonstrate photoluminescence.
2D Perovskite Micro-optics Enabled by Direct Femtosecond-Laser Projection Lithography
Authors: Cherepakhin A. , Zhizhchenko A. , Porfirev A. , Pushkarev A. , Makarov S. , Kuchmizhak A. 
Published: November 2021

Abstract
Using direct femtosecond-laser projection lithography in chemically synthesized CsPbBr3 perovskite microcrystals we demonstrate high-throughput fabrication of advanced binary microscale optical elements for nanofocusing as well as generation of high-order optical vortex beams. The obtained results highlight the CsPbBr3 microcrystals as a promising material for realization of various complicated 2D micro-optical elements and holograms that can be directly imprinted using non-destructive and practically relevant laser technologies.