bluuebunny/crossref_metadata_2025_split huggingface dataset:
Influence of heteroatoms on optical properties and photoluminescence kinetics of carbon dots
Authors: Arefina I A , Khavlyuk P D , Stepanidenko E A , Dubavik A , Cherevkov S A , Baranov A V , Fedorov A V , Ushakova E V , Rogach A L 
Published: April 2020

Abstract
Carbon dots have attracted much attention due to the ease of synthetic methods and their stable photoluminescence with relatively high quantum yield. By the doping of carbon dot by heteroatoms the optical transitions can be tuned in a wide spectral range. In this work, the impact of heteroatoms on the optical properties of carbon dots has been investigated: the appearance of the luminescent states attributed to the CD surface states and the dependence of the photoluminescence lifetime versus emission wavelength have been revealed.
Optical modes in perovskite nanowire with shallow bi-periodic grating
Authors: Berestennikov A , Gorlach M , Makarov S , Khanikaev A 
Published: April 2020

Abstract
In this work, we investigate electromagnetic modes supported by a perovskite CsPbBr3 nanowire with a shallow periodic grating on top. By creating a domain-wall geometry, we introduce a topological defect into the nanowire and observe a defect-localized lasing state. By tuning the parameters of the structure we ensure that the frequency of the localized state fits the frequency of exciton resonance in perovskite and perform full-wave numerical simulations of the field distribution for such state.
Bottom-up nano-integration route for modified carbon nanotube spintronic device fabrication
Authors: Mosse I S , de Sousa A S , Ncube S , Coleman C , Bhattacharyya S , Irzhak A , Gratowski S , Koledov V 
Published: April 2020

Abstract
This study is focused on a bottom-up nano-integration route for the production of carbon based spintronic devices. In order to enhance magnetic interactions along nanotube walls a controlled synthetic chemical technique is utilized, this method is based on a two-step method which firstly looks at the functionalization of nanotubes (carbonyl groups) and subsequently the attachment of an organo-metallic complex to the carbonyl group. The system is then characterized in bulk, including magnetometry analysis as well as transport at low temperatures. Mesoscopic electron-spin correlations have been observed as well as a clear crossover from superparamagnetism to weakly ferromagnetic depending on the functionalization technique. We then demonstrate a novel fabrication technique based on nano-integration utilizing a nano-tweezer created from a memory metal alloy. The devices envisioned include quantum rings, crossed junction as well as fine network structures that can be manipulated using nano-probes. As the carbon nanotubes have been functionalized with nanoscale magnetic molecules, such devices are interesting for novel spintronic applications.
Application of laser radiation for creation of metamaterial based on rapidly quenched shape memory TiNiCu alloy
Authors: Borodako K A , Shelyakov A V , Sitnikov N N , Irzhak A V , Tabachkova N Yu , Ivanov A A , Koledov V V 
Published: April 2020

Abstract
The work deals with application of laser radiation for creation of metamaterial – layered structural composite based on rapidly quenched TiNiCu thin ribbon. Structural properties of the composite were examined by transmission and scanning electron microscopy. Considerable two-way shape memory effect was achieved and studied.
Nontrivial invisibility induced by optical hybrid anapole
Authors: Canós Valero A. , Gurvitz E. , Miroshnichenko A.E. , Shalin A.S. 
Published: April 2020

Abstract
The novel hybrid anapole states supported by dielectric nanoparticles are associated with the condition whem all the dominant Cartesian multipoles interfere destructively with their corresponding toroidal counterparts. They are characterized by a negligible light scattering for any observation direction. In the current work, we have proven the existence of high order hybrid anapole states in the visible range, resulting in a drastic reduction of the scattered radiation from a cylindrical nanoparticle with dimensions comparable to the wavelength. We demonstrate it by expanding the numerically calculated scattering cross section of the nanoparticle in terms of the Cartesian multipole decomposition. The simulations illustrate the simultaneous resonant suppression of the four leading multipole contributions to radiation (e.g. electric and magnetic dipoles and quadrupoles). Our results confirm the possibility to observe the effect experimentally, paving the way for future applications in dielectric nanophotonics.
A Transient Grating Method to Measure the Dispersion of Elastic Waves in Nanostructures
Authors: Charron E. , Lu L. , Bonello B. , Boyko O. , Glushkov E. , Glushkova N. , Tchernycheva M. , Gogneau N. 
Published: April 2020

Abstract
We describe the so-called “Transient Grating Method” which is a non-invasive experimental technique well suited to measure the dispersion properties of ordered or disordered nanostructures and thin films, at frequencies up to a few GHz. This pump-and-probe technique involves the interference pattern produced by two in-coming IR optical pulses to set a standing elastic wave on the surface of the sample through photoelastic processes. The wave vector of this elastic wave can be easily tuned by adjusting the angle between the two incident beams. Two continuous visible laser beams in a heterodyne detection scheme are used to detect the vibrations on the surface and in turn the dispersion of the related elastic modes. The achievements of the technique are illustrated by the measurement of the dispersion of surface acoustic waves in piezogenerators consisting of GaN nanowires embedded into a dielectric matrix (HSQ). We then report on the analysis of the experimental data that allowed extracting the elastic parameters of this composite medium.
Nano-manipulation and laser treatment as alternative routes for strain engineering in Graphene
Authors: Coleman C , Erasmus R , Mtsuko D , Gratowski S von , Koledov V , Bhattacharyya S 
Published: April 2020

Abstract
In this work we present two alternative routes for strain engineering in graphene. The first technique involves a laser treatment a low power that was found to create micro-bubbles on single layer graphene flakes. The effect of strain and doping of the graphene along these micro-bubbles is mapped and analysed using Raman Spectroscopy and it is found that a pronounced split in the G-band phonon mode can be attributed to large strain induction. The second technique discussed involves the use of nano-manipulating probes to manoeuvre and deform multilayer graphene flakes. Devices fabricated from such deformed flakes exhibit transport deviating from the expected 2D/quasi-2D electron gas observed in single layer graphene and graphite. We observe signatures of quantum linear magnetoresistance up to large fields in such devices.
Continuous Heating Microwave System Based on Mie Resonances
Authors: Jacobsen R E , Arslanagić S , Lavrinenko A V 
Published: April 2020

Abstract
Nowadays microwave heating is a part of many people’s daily life, whereas industrial microwave heating is not as widespread. The permittivity of many liquids is highly temperature dependent, which makes it difficult to control the heating process when using microwaves. Presently, we propose two continuous heating microwave systems for heating, pasteurization and sterilization of liquids. Both designs utilize resonances in cylindrical water-filled cavities of different sizes so that high absorption through the whole heating process is achieved. The proposed systems can heat water from 0 to 100 °C, and their effectiveness is significantly higher than that of a single water cavity.
Excitonic nature of dispersion of two-dimensional transition metal dichalcogenides and effect of annealing on excitons
Authors: Ermolaev G. A. , Komissar D. A. , Krivova G. M. , Tatarkin D. E. , Voronin K. V. , Yakubovsky D. I. , Stebunov Y. V. , Arsenin A. V. , Novikov S. M. , Volkov V. S. 
Published: April 2020

Abstract
In present study, we develop an effective and universal technique for retrieving dispersion of bulk and monolayer TMDs from spectroscopic ellipsometry measurements. The basis of the method is excitonic nature of the dispersion. In addition, we demonstrate beneficial influence of annealing on optical properties of MoS2.
Polymer capsules modified with iron oxide nanoparticles as an effective platform for MRI visualization and drug delivery
Authors: Fatkhutdinova L I , Andreychenko A , Brui E , Timin A S , Pavlovskaya G E , Khlobystov A N , Zyuzin M V 
Published: April 2020

Abstract
Efficiency of existing (usually toxic) drugs can be increased substantially with the targeted effect on the site of the disease. A potential platform for the targeted drug delivery can be polymer capsules. This will help reduce side effects on the human body and start treatment at the early stages of the disease. Modification of such capsules with the magnetic nanoparticles allows their visualization using magnetic resonance imaging (MRI). In this study the use of polymer microcapsules modified with iron oxide nanoparticles are employed as contrast agents for T2-weighted magnetic resonance (MR) images, the possibility of their implementation as for drug delivery carriers are discussed. For this, two different types of polymer capsules are synthesized. The results on the spin-spin and spin-lattice relaxivities were obtained.
Scattering-matrix analysis of nanoparticle lattices in dipole approximation
Authors: Fradkin I M , Dyakov S A , Gippius N A 
Published: April 2020

Abstract
Fourier modal method (FMM) proved itself as an effective technique for investigation of layered periodic structures. However, it fails to deal with arrays of small particles because of high gradients in a local field. In this paper, we demonstrate the capability of the method, which is based on the construction of scattering matrices of arrays of resonant nanoparticles semianalytically in discrete dipole approximation (DDA). This approach is much faster than conventional ones and therefore provides an opportunity for thorough consideration of various layered structures with small periodic inclusions in terms of the RCWA. The performance of the considered method is demonstrated on an example of plasmonic lattices embedded in a homogeneous ambience and placed inside and onto an optical waveguide. Localized surface plasmon resonances (LSPRs), lattice plasmon resonances (LPRs) and their hybridization with photonic guided modes are observed. High precision of this calculations is confirmed by comparison with finite element method (FEM).
Studying localized surface plasmon resonances in the THz region for subwavelength spiral disks
Authors: Gerasimov V V , Kuznetsov S A , Lemzyakov A G , Hafizov R R 
Published: April 2020

Abstract
Spoof localized surface plasmon resonances (LSPRs) in the THz range are promising for bio-sensing and spectroscopy. Using long spiral grooves allows improving the surface mode confinement of LSPRs in the long-wavelength region. Our numerical simulations of sub-wavelength spiral gold disks in the range of 0.04–6 THz have shown that in case of Drude conductivity and normal incidence of EM radiation only the first- and second-order dipole localized surface plasmon resonances (LSPRs) are excited. High order resonances arise at inclined incidence. The spectra and 2D distributions of the EM field at the resonant frequencies depend on the number of spiral arms and symmetry of the spiral structure.
Arbitrary-order optical differentiation in refection by sequence of first-order differentiators
Authors: Golovastikov Nikita V. , Bykov Dmitry A. , Doskolovich Leonid L. 
Published: April 2020

Abstract
We propose a simple analytical method for designing arbitrary-order optical differentiators operating in reflection by successively arranging several first-order optical differentiators. The approach is based on the scattering matrix analysis, does not involve numerical optimization and is valid for differentiators of arbitrary configurations. The numerical simulation results demonstrate high-quality differentiation of a picosecond pulse for up to the fourth order. The proposed method can find application in the design of analogue optical computing and optical information processing systems.
Engineering coupling in electromagnetic topological models via staggered bianisotropy
Authors: Gorlach M A , Zhirihin D V , Bobylev D A , Gorlach A A , Li S V , Sokolov D Y , Slobozhanyuk A P , Khanikaev A B 
Published: April 2020

Abstract
Magneto-electric coupling known also as bianisotropy plays a fundamental role in time-reversal-invariant photonic topological metamaterials being responsible for opening of a topological bandgap. To further uncover the fundamental link between bianisotropy and photonic topological states, we investigate scattering of light from the individual bianisotropic disk and reveal polarization dependence of scattering which provides a photonic analogue of spin Hall effect originating from the coupling between electric and magnetic responses of the disk. Based on the field patterns from the individual meta-atom, we further design a linear array of such bianisotropic disks. Employing coupled-dipole model, we demonstrate that local modification of the disk bianisotropy translates into the modification of coupling constants in the effective photonic Hamiltonian thus opening an avenue to engineer electromagnetic topological states via the staggered bianisotropy pattern. To confirm our findings, we realize a representative example of such one-dimensional array experimentally and detect the interface states at the domain wall.
The dependence of the exciton binding energies on quantum well widths of the donor doped GaAs/AlGaAs QW influencing on the intersubband transition
Authors: Dommelen Paphavee van , Jarusirirangsi Kanothai 
Published: April 2020

Abstract
In this research, we theoretically investigated the exciton binding energies as a function of QW widths with the variation of the percent alloy contents. For any certain percent of alloy contents, the exciton binding energies increase proportionally with the increasing of QW widths. We also simulated the exciton binding energies as a function of the percent alloy contents of AlxGa1-xAs barrier with the variation of QW widths. For the narrower QW widths, with any certain percent of alloy contents, the exciton binding energies show higher discrete energy characteristic compared with the wider well widths. These results can explain the intersubband transition with MIR and Far-IR emission between donor doped levels in conduction band.
Auger recombination via deep energy levels as a potential cause of efficiency droop in InGaN/GaN LEDs
Authors: Karpova A A , Samosvat D M , Zegrya G G 
Published: April 2020

Abstract
In the present work a mechanism of nonradiative radiation via deep energy levels is considered for InGaN/GaN LEDs from the first principles. The coefficient and time of such Auger recombination are evaluated numerically and are shown to be enough for causing the efficiency droop in blue and green InGaN/GaN LEDs.
Electron-photonic topological states on the surface of a bulk semiconductor driven by a high-frequency field
Authors: Kibis O. V. , Kyriienko O. , Shelykh I. A. 
Published: April 2020

Abstract
It is shown theoretically that the strong coupling of electrons in a bulk gapless semiconductor (HgTe) to a circularly polarized high-frequency electromagnetic field induces topological states on the surface of the semiconductor. Their branches lie near the center of the Brillouin zone and have the Dirac dispersion. Thus, the light-induced topological phase transition in the semiconductor appears. The structure of the found surface states is studied both analytically and numerically in the broad range of their parameters.
Floquet engineering of 2D materials
Authors: Kibis O. V. , Iorsh I. V. , Shelykh I. A. 
Published: April 2020

Abstract
We demonstrate theoretically that the interaction of electrons in the 2D materials (gapped graphene and transition metal dichalchogenide monolayer) with a strong off-resonant electromagnetic field substantially renormalizes their band structure, including the band gaps and the spin-orbit splitting. Moreover, the renormalized electronic parameters drastically depend on the field polarization. Namely, a linearly polarized field always decreases the band gap (and, particularly, can turn the gap into zero), whereas a circularly polarized field breaks the equivalence of valleys in different points of the Brillouin zone and can both increase and decrease corresponding band gaps. As a consequence, the field can serve an effective tool to control spin and valley properties of the 2D materials and be potentially exploited in optoelectronic applications.
Measurement surface plasmon polariton assisted optical force using a carbon nanowhisker mechanical resonator
Authors: Kislov D A , Mukhin I S , Golubok A O , Lukashenko S Yu , Shalin A S 
Published: April 2020

Abstract
Optical tweezers are widely used for manipulating nano- and micro sized particles. The presence of a special plasmon substrate can significantly affect the optical forces acting on an object. This paper discusses the possibility of experimental measuring optical plasmon forces using a mechanical resonator based on a carbon nanowhisker. A mathematical model describing the effect of optical forces on nanowhisker oscillations with an additional nanoparticle at the end is presented with taking into account the effect of surface plasmon waves on the substrate.
Q/V enhancement of Si micropillar resonator with Bragg reflectors in BIC regime
Authors: Kolodny Stanislav , Iorsh Ivan 
Published: April 2020

Abstract
Recent progress in nanophotonics is increasingly aimed at the use of fully dielectric nanoparticles that support magnetic and electric Mie resonances, but as the Mi theory predicts, dielectric subwavelength resonators have extremely low Q-values. However it has been shown that using so-called bound states in the continuum (BIC) allows to achieve high values of Q for high index cylindrical resonator. Here we show that the use distributed Bragg reflectors in regime of BIC allows to drastically increase the absolute values of quality factors, and what is even more important quality factor to mode volume ratio, the quantity proportional to the Purcell factor which is of the immense importance for triggering nonlinear optical processes in nanophotonic devices.
A simple calibration-free method of complex permittivity extraction
Authors: Kurdjumov S. , Filonov D. , Kretov E. , Ivanov V. , Ginzburg P. 
Published: April 2020

Abstract
Here we present a new calibration-free method for relative complex permittivity extraction, which allows using accessible and cheap materials and simplifies the measurement process. The method combines the advantages of resonant and non-resonant techniques and provides results for liquids and solids in 0.5-5GHz frequency band in dependence on the material type. The essence of the proposed method is based on measuring of the magnetic dipole resonance of a spherical sample. The size of such a sphere can be dynamically changed making it possible to evaluate its permittivity at different frequencies. Mie theory serves as the basis for connecting the resonant frequency of the sample with the real part of the permittivity, while imaginary part can be found from Q-factor. In this work we demonstrate the efficiency of the method for water. In addition, we evaluate the applicability of the method for lossy materials.
Mesoporous particles for transdermal delivery of the antifungal drug griseofulvin
Authors: Lengert E V , Averkhovskii R , Genina E A , Terentyuk G S , Svenskaya Y I 
Published: April 2020

Abstract
Griseofulvin is an antifungal antibiotic applying for the treatment of dermatophyte infections. The most common delivery route of this drug is oral. The dosage of griseofulvin varies depending on whether the drug is administered as a microsized or an ultramicrosized preparation. In order to avoid possible incidental systemic toxicity associated with the oral delivery route and reduce the therapeutic dose, a novel approach for the griseofulvin administration is proposed. Immobilization of the drug into mesoporous calcium carbonate particles together with their further ultrasonically-assisted topical application provides the efficient transdermal transportation. Accumulation of griseofulvin-loaded carriers inside hair follicles of the rat is demonstrated in vivo, allowing by this means the targeted delivery of the antifungal drug to the lesion area of skin. No significant toxicity of the system is shown for rat and human fibroblasts cells in vitro.
A new solution of permittivity and permeability measurement system with temperature variation
Authors: Letertre Thibaut , Jegou Carole , Pouliguen Philippe , Sabouroux Pierre 
Published: April 2020

Abstract
Nowadays, permittivity and permeability measurement are well-known in the industrial domain and research laboratory. It became unavoidable in few domains as biomedical and aeronautics. In this way, many researchers or engineers are committing to working on new measurement setup, complex or not working on a wide band of frequency. However, the thermal dependence of dielectric and magnetic structure is quite complicated to determinate, even though it became more and more important to know. As in the case of radomes antennas, the air friction produces increasing of temperature and thereby electromagnetic characteristics variation. Accordingly, we propose in this paper, a new characteristics measurement system of solid material between 100MHZ and 15GHz coupled to a high-temperature thermoregulation system designed to reach a few hundred degrees.
A practical realization of an artificial magnetic shield for preclinical birdcage RF coils
Authors: Lezhennikova K. , Hurshkainen A. , Simovski C. , Abdeddaim R. , Enoch S. , Raaijmakers A. , Melchakova I. , Glybovski S. 
Published: April 2020

Abstract
In the most of magnetic resonance imaging (MRI) systems, a conventional radiofrequency (RF) electric shield is typically placed around an RF volume coil to avoid the interaction with the other components of the system. Disadvantageously metal shields reduce the transmit efficiency of the RF coil as well as its receive sensitivity due to out-ofphase reflection of electromagnetic waves. In contrast, an ideal magnetic shield having high surface impedance provides in-phase reflection, which can be promising for improvement of RF coil’s performance. In this work, we propose an artificial magnetic shield based on a cylindrical miniaturized corrugated structure to improve characteristics of a small-animal birdcage coil at 7T. The coil was simulated in the presence of the metal and ideal magnetic shield as well as the proposed structure. The results demonstrate enhancement of the coil’s performance in the presence of the proposed shield, which is comparable with an ideal one.
Controlling liquid crystal alignment by micro-patterned substrates
Authors: Mamonova A V , Gorkunov M V , Kasyanova I V , Artemov V V , Palto S P 
Published: April 2020

Abstract
We propose a method of controlling the liquid crystal alignment at rubbed polyimide substrates by patterning them periodically with the focused ion beam. The pattern duty factor sets the alignment conditions which determine the light phase retardation that can be precisely varied in a range from zero to that of the background. The method opens up opportunities for creating tunable optical devices.