Splitting Width Research Articles

Analysis and Implementation of Metamaterial-Inspired Microstrip Antenna for Wireless Applications

In this paper, a novel metamaterial-inspired microstrip antenna for wireless applications is proposed. The proposed design consists of a radiating path on top and a uniformly distributed split ring-shaped metamaterial structure on the ground. The presented antenna of 50´38 mm with a thickness of 1.6 mm is printed on FR4 substrate and resonates at 1.80 GHz. The design was fabricated and the measured results were found to be in accordance with the simulations. The goal is accomplished by loading uniformly distributed split ring-shaped metamaterial structures on the ground plane of this antenna. The results of the experiments show that using the metamaterial structure on the ground plane improved gain from 4.34 to 7.3 dB, efficiency from 5.94 to 7.8 dB compared to the conventional patch antenna. This introduction in the ground plane exhibits return loss up to –38 dB and modified the gain and directivity to 7.3 and 7.8 dB respectively. The presented antenna has 45 MHz bandwidth. The presented design is proven by simulated surface current, S parameter, VSWR, radiation pattern. We have also investigated the effect of substrate permittivity, split width, and inter-element spacing in a split ring-shaped metamaterial structure on return loss. This directive antenna is designed for the applications of wireless local area networks and other Internet of things-based applications.

Topologically protected subradiant cavity polaritons through linewidth narrowing enabled by dissipationless edge states

Cavity polaritons derived from strong light–matter interaction provide a basis for efficient manipulation of quantum states via cavity field. Polaritons with narrow linewidth and long lifetime are appealing in applications, such as quantum sensing and storage. Here, we propose a prototypical arrangement to implement a whispering-gallery-mode resonator with one-dimensional topological atom mirror, which allows to boost the lifetime of cavity polaritons over an order of magnitude. This considerable enhancement attributes to the coupling of polaritonic states to dissipationless edge states protected by the topological bandgap of atom mirror that suppresses the leakage of cavity modes. When exceeding the width of Rabi splitting, topological bandgap can further reduce the dissipation from polaritonic states to bulk states, giving arise to subradiant cavity polaritons with extremely sharp linewidth. The resultant Rabi oscillation experiences decay rate lower than the free-space decay of a single quantum emitter. Inheriting from the topologically protected properties of edge states, the subradiance of cavity polaritons can be preserved in disordered atom mirror with moderate perturbations involving the atomic frequency, interaction strengths and location fluctuations. Our work opens up a new paradigm of topology-engineered quantum states with robust quantum coherence for future applications in quantum computing and network.

Quantum-informed plasmonics for strong coupling: the role of electron spill-out

The effect of nonlocality on the optical response of metals lies at the forefront of research in nanoscale physics and, in particular, quantum plasmonics. In alkali metals, nonlocality manifests predominantly as electron density spill-out at the metal boundary, and as surface-enabled Landau damping. For an accurate description of plasmonic modes, these effects need be taken into account in the theoretical modeling of the material. The resulting modal frequency shifts and broadening become particularly relevant when dealing with the strong interaction between plasmons and excitons, where hybrid modes emerge and the way they are affected can reflect modifications of the coupling strength. Both nonlocal phenomena can be incorporated in the classical local theory by applying a surface-response formalism embodied by the Feibelman parameters. Here, we implement local surface-response corrections in Mie theory to study the optical response of spherical plasmonic–excitonic composites in core–shell configurations. We investigate sodium, a jellium metal dominated by spill-out, for which it has been anticipated that nonlocal corrections should lead to an observable change in the coupling strength, appearing as a modification of the width of the mode splitting. We show that, contrary to expectations, the influence of nonlocality on the anticrossing is minimal, thus validating the accuracy of the local response approximation in strong-coupling photonics.

Characterisation of storage efficiency in magnetic field for extending coherence time of Pr:YSO quantum memory

Quantum memory (QM) is vital in enabling the storage and retrieval of photonic quantum states. Quantum repeaters that circumvent transmission losses over long distances can be realised by loading QMs inside. In this study, we implement spin-wave (SW) storage to extend storage time using Pr-based atomic frequency comb (AFC) QM. Furthermore, the generation of an AFC under a static magnetic field was investigated. The AFC QM was prepared with 2.5 μs of the storage time and the SW storage of 50 μs was demonstrated with and without a magnetic field. This study provides a basis for improving Pr-based AFC systems.

Exploring spin states and ligand field splitting in metal complexes: a theoretical analysis of spin-orbital interactions and magnetic properties.

Metal complexes are pivotal in diverse fields due to their wide array of functionalities, including magnetism, conductivity, and photoresponsiveness. These functionalities are intricately linked to the phenomenon of ligand field splitting, yet controlling the magnitude of this splitting within metal complexes presents a significant challenge. This study aims to address this challenge by developing a novel 2D spectrochemical series, integrating two critical parameters: metal ions and ligands. Employing the DV-Xα molecular orbital method, we directly calculated ligand field splitting width, enabling a detailed assessment of energy splitting trends. Our results reveal that the magnitude of ligand field splitting, encompassing 17 metal types and 29 ligand types, can be precisely controlled. This represents a significant advancement over traditional spectrochemical series, such as those proposed by R. Tsuchida, which predominantly focus on either ligands or metals in isolation. Additionally, our study extends to the calculation of spin states in these metal complexes, contributing valuable insights for the development of magnetic materials. We demonstrate that the relative ligand field splitting and spin polarization can be used to predict spin states, offering a new perspective in material design and functionality. These findings not only enhance our understanding of ligand field splitting in metal complexes but also provide a comprehensive framework for predicting their electronic and magnetic properties, paving the way for innovative applications in material science and coordination chemistry.

Prediction of 4f-5d Transition Energy of Ce3+ in Oxides By First-Principles Calculations and Machine Learning

A Ce3+ ion has only one electron in the 4f orbitals and its 4f-5d transition energy is strongly influenced by the width of the crystal field splitting of the 5d orbitals. In other words, the absorption and emission wavelengths of Ce3+ in crystals can be widely controlled by changing the ligand field environment. As an example of Ce3+-doped phosphor, Ce:YAG (Y3Al5O12) is widely used as an yellow phosphor for standard white LEDs. Therefore, novel phosphors with desired emission colors can be developed by adding Ce3+ to appropriate host crystals.In this work, we aimed to construct an efficient prediction model for the transition energy of Ce3+ in oxide crystals. Small clusters consisting of the substituted Ce3+ ion and the first-neighbor anions were constructed and molecular orbital calculations were performed using the relativistic discrete-variational Xα (DV-Xα) method. Then machine learning based on structural and electronic state parameters was performed to create a predictive model for the 4f-5d transition energy of Ce3+ in crystals. By creating the correlation diagrams, the influence of each parameter on the transition energy was analyzed in detail.

Floquet engineering of selective magnon–magnon coupling in synthetic antiferromagnets

Floquet engineering is a widely applied method for temporally periodic driving in various quantum systems, capable of inducing emergent phenomena, such as Floquet states, Floquet topological insulators, and temporal crystals. In this work, we study the selective magnon–magnon coupling between sidebands by introducing Floquet engineering into magnonic system: coupling between Floquet sidebands occurs only when there is an odd order difference. In addition to the coherent coupling between the optical and acoustic modes in synthetic antiferromagnet, a Floquet coupling is observed as the secondary splitting of the two hybridized magnon modes. The splitting width of Floquet coupling exhibits different dependence with driving amplitude, i.e., linearly increasing for weak driving regime and nonlinearly varying for strong driving regime. Specifically, the nonlinear dependence arises from the coupling between hybridized sidebands that exhibit odd order differences in their components. Our findings could promote the further development of Floquet magnonics and its application for quantum information.

Redox-induced structural changes in Keggin-type tungstophosphate investigated by high-energy-resolution fluorescence detection X-ray absorption spectroscopy

Redox-active heteropolyanions are widely applied to redox catalysts and electron acceptors and the understanding of their reduced states in solution is essential. In this study, the structural changes of Keggin-type tungstophosphate: [PW12O40]3− induced by electrochemical reduction were investigated using W L3-edge X-ray absorption near-edge structure (XANES) spectra in high-energy-resolution fluorescence detection (HERFD) mode. W L3-edge HERFD-XANES spectra revealed the changes in the electronic state of W species and local structure of {WO6} units, which were negligible in conventional transmittance mode; the peak intensities of the split two white line peaks were switched by the electrochemical reduction accompanied by enlargement of the splitting width. Our findings suggest that the injected electron was delocalized on whole {WO6} units in [PW12O40]3− and that the improved symmetry of {WO6} units compensated for the change in valence due to the injected electron.

Modifications in structure dependent magnetic parameters of Nd-doped Ba–Ca hexaferrites synthesized by sol gel using lemon extract as a fuel

The Nd doped Ba–Ca ferrites, Ba0.5Ca0.5NdXFe12-XO19 (x = 0 to 0.2, Δx = 0.05) are synthetically prepared by sol gel auto-ignition method using lemon extract as the fuel. Differential thermal analysis of the thermogravimetric spectrum clearly exhibits the thermal decomposition till 1050 °C. The powder X-ray diffraction (XRD) patterns of the hexaferrites sintered at 1050 °C reveals the single-phase M-type hexaferrites possessing nano dimensions. The lattice parameters, unit cell volumes, densities, and porosities of the hexaferrites were computed from the XRD patterns. The morphology of the synthesized hexaferrites is analyzed from the digital images of the powder samples obtained by utilizing Field Emission Scanning Electron Microscope (FESEM). The relative abundance of the elements within the hexaferrites was studied by means of Energy Dispersive X-Ray Analysis (EDAX). The oxidation states and valence of the metal elements within the hexaferrites are confirmed by means of the X-ray photoelectron spectroscopy (XPS). Magnetic parameters such as coercivity, saturation magnetization, and remanence are measured by using Vibrating-Sample Magnetometer (VSM). The Mössbauer spectra of the hexaferrites are obtained to analyze the hyperfine interactions by measuring the parameters such as hyperfine field, isomer shift, quadrupole splitting, relative area, and outer line width. The varying Nd doping concentrations have modulated the magnetic parameters of Ba–Ca hexaferrites showing the control of Nd doping on magnetic behavior of the hexaferrite. The moderate saturation magnetization and high coercivity values suggest the possible use of the hexaferrites as the permanent magnets.

Effects of dilute low molecular weight poly(ethylene oxide) solutions in immiscible radial viscous fingering instabilities

We experimentally study the effects of normal stress differences in the immiscible radial viscous fingering instability in a Hele–Shaw cell. Dilute low molecular weight poly(ethylene oxide) (PEO) solutions are used as the displaced fluid to focus on elastic effects without shear-thinning behavior. The molecular weight of PEO is varied to investigate the effects of normal stress differences. The experimental observations reveal that nonmonotonic and opposing effects are evident depending on the molecular weight of the PEO and the stage of the radial viscous fingering evolution. Decreases in the PEO molecular weight reduce the number of fingers and widen the finger width in the early stage. However, the increase in the PEO molecular weight promotes tip splitting and narrows finger width in the early stage but suppresses tip splitting in the intermediate stage. Weissenberg numbers are estimated at different stages of radial viscous fingering instabilities. Tip splitting occurs at the highest Weissenberg number covered in this study and suppression of tip splitting is observed at intermediate Weissenberg numbers. At low Weissenberg numbers, we observe an increased finger width and a reduced number of fingers.

Investigate the Possibility of Using Phosphorescence in Clinical Oncology as an Early Prognostic Test in Detecting Brain Carcinogenesis

Phosphorescence is considered one of the non-invasive glioblastoma testing methods based on studying molecular energy and the metabolism of L-tryptophan (Trp) through KP, which provides essential information on regulating immunity and neuronal function. This study aimed to conduct a feasibility study using phosphorescence in clinical oncology as an early prognostic test in detecting Glioblastoma. This study was conducted on 1039 patients who were operated on with follow-up between January 1, 2014, and December 1, 2022, and retrospectively evaluated in participating institutions in Ukraine (the Department of Oncology, Radiation Therapy, Oncosurgery, and Palliative Care at the Kharkiv National Medical University). Method of protein phosphorescence detection included two steps. During the first step, of luminol-dependent phosphorescence intensity in serum was carried out after its activation by the light source, according to the spectrofluorimeter method, as follows. At a temperature of 30 °C, serum drops were dried for 20 min to form a solid film. After that, we put the quartz plate with dried serum in a phosphoroscope of luminescent complex and measured the intensity. With the help of Max-Flux Diffraction Optic Parallel Beam Graded Multilayer Monochromator (Rigaku Americas Corporation) following spectral lines as 297, 313, 334, 365, 404, and 434 nm were distinguished and absorbed by serum film in the form of light quantum. The monochromator exit split width was 0.5 mm. Considering the limitations of each of the non-invasive tools currently available, phosphorescence-based diagnostic methods are ideally integrated into the NIGT platform: a non-invasive approach for visualizing a tumor and its main tumor characteristics in the spatial and temporal order. Because trp is present in virtually every cell in the body, these fluorescent and phosphorescent fingerprints can be used to detect cancer in many different organs. Using phosphorescence, it is possible to create predictive models for GBM in both primary and secondary diagnostics. This will assist clinicians in selecting the appropriate treatment option, monitoring treatment, and adapting to the era of patient-centered precision medicine.

Unit for Splitting Degraded Mountain Meadows and Pastures Based on a Mini Tractor

Soil splitting is used to prevent water and wind erosion of soils, improve their water-air regime in mountain meadows and pastures. It reduces soil loss, improves plants moisture supply, affects herbage species composition and increases fodder lands yield. The advantages of a small-sized unit have been described ensuring gentle splitting with the formation of water-absorbing splits on the slopes. (Research purpose) To create a small-sized maneuverable splitter for mountain meadows and pastures, to determine its agrotechnical parameters, to give a graphic-analytical substantiation of the splitting working process in areas with a slope of up to 12 degrees. (Materials and methods) A technical examination of the unit laboratory sample was carried out at an altitude of 1540 meters above the sea level. The slitter working width was determined by two passes at 25 points located at the intervals of at least 1 meter in the unit movement direction. (Results and discussion) A splitter for the mountain area was built on the basis of a Feng Shou 180 mini-tractor, reducing the load on the soil. An optimal arrangement scheme for the splitter working bodies has been developed when moving along a slope. The scheme of the unit movement on the slope was substantiated. The following technological parameters were set: the distance between the splits is 1,000 millimeters, the depth of slip cutting is 200220 millimeters, the split width is 10-30 millimeters. (Conclusions) It was determined having penetrated into the soil, the shift in the reaction of the working body located on the slope top side of the tractor axis stabilizes the position of the unit when moving across the slope, preventing it from sliding down. It was found that being 1,000 mm apart from each other and of the width of not more than 35 mm, the splitter cutting-knives do not destroy the turf layer, do not damage the edges of the slot. The use of a Feng Shou 180 mini-tractor enabled to decrease the unit weight load of on the agrocenosis during movement.

Measurement of amino acid solutions based on novel optical effects

We studied the nonlinear optical properties of a square split-ring structure of magnetic metamaterials and the mechanism by which a non-centrosymmetric silver structure generates the second harmonic within the near-infrared band. We also analyzed the effect of the silver structure on the second harmonic and applied the silver structure in an air cavity-silver-glass structure, which is an insulator-metal-insulator structure, for sensing. By identifying the effect of different refractive indexes on the transmission spectrum, we obtained the intrinsic relation between the refractive index and the wavelength at which the second harmonic is excited. The experimental results indicate that with the growth of the refractive index, the second harmonic has an evident red shift and that by changing the shape and split width of the silver structure, the sensitivity is significantly improved, measurement of amino acid solutions up to 1007.2 nm/RIU. This study brings new insight into the application of second harmonics with nonlinear effects in the sensing field.

Electric-Field-Coupled Resonator Antenna for 5G Applications.

In this paper, a compact wideband patch antenna comprising a modified electric-field-coupled resonator with parasitic elements is presented. The resonance at low frequency is achieved due to the electric field polarization along the split of the conventional LC (inductive-capacitive) structure. However, this antenna gives low bandwidth as well as low gain. Some evolutionary techniques are adopted to get a compact wideband antenna at 3GPP bands of 5G. The split width and the ground plane are modified to achieve enhanced bandwidth with good impedance matching, whereas the addition of the parasitic elements on both sides of the microstrip feed line enhances the gain with a slight reduction of bandwidth. The compact dimension of the proposed antenna is 0.26 λL × 0.26 λL × 0.017 λL, where λL is the free space wavelength at the lowest frequency. A prototype of the presented design is fabricated and measured. Measurement shows that the antenna has an operating bandwidth of 19.74% for |S11| < −10 dB where the gain of 1.15 dBi is realized. In addition, the radiation pattern is omnidirectional in the horizontal plane and dumbbell shaped in the elevation plane. The cross-polarization levels in both planes are less than −12 dB.

Flexible Manipulation of the Reflected Wavefront Using Acoustic Metasurface with Split Hollow Cuboid.

This work proposes a method for actively constructing acoustic metasurface (AMS) based on the split hollow cuboid (SHC) structure of local resonance, with the designed AMS flexibly manipulating the direction of reflected acoustic waves at a given frequency range. The AMS was obtained by precisely adjusting any one or two types of structural parameters of the SHC unit, which included the diameter of the split hole, the length, width, height, and shell thickness of the SHC. The simulation results showed that the AMS can flexibly manipulate the direction of the reflected acoustic waves, and the anomalous reflection angle obeys the generalized Snell’s law. Furthermore, among the five structural parameters, the AMS’s response frequency band is widest with the hole diameter and height, followed by the length and width, and narrowest with the shell thickness. It is worth noting that comprehensive manipulation of two parameters not only broadens the response frequency band, but also strengthens the effect of the anomalous reflection at the same response frequency. The subwavelength size of the AMS constructed with such a comprehensive method has the advantages of a small size, wide response band, simple preparation, and flexible modulation, and can be widely used in various fields, such as medical imaging and underwater stealth.

Photonic crystals with split ring unit cells for subwavelength light confinement.

Here we report a photonic crystal with a split ring unit cell shape that demonstrates an order of magnitude larger peak electric field energy density compared with that of a traditional photonic crystal. Split ring photonic crystals possess several subwavelength tuning parameters, including split ring rotation angle and split width, which can be leveraged to modify light confinement for specific applications. Modifying the split ring's parameters allows for tuning of the peak electric field energy density in the split by over one order of magnitude and tuning of the air band edge wavelength by nearly 10 nm in the near infrared region. Designed to have highly focused optical energy in an accessible subwavelength gap, the split ring photonic crystal is well suited for applications including optical biosensing, optical trapping, and enhanced emission from a quantum dot or other nanoscale emitter that could be incorporated in the split.

The influence of collision energy on magnetically tuned 6Li-6Li Feshbach resonance

The effect of collision energy on the magnetically tuned 6Li–6Li Feshbach resonance (FR) is investigated theoretically by using the coupled-channel (CC) method for the collision energy ranging from 1 μK ⋅ k B to 100 μK ⋅ k B. At the collision energy of 1 μK ⋅ k B, the resonance positions calculated are 543.152 Gs (s wave, the unit 1 Gs = 10−4 T), 185.109 Gs (p wave |ml | = 0), and 185.113 Gs (p wave |ml | = 1), respectively. The p-wave FR near 185 Gs exibits a doublet structure of 4 mGs, associated with dipole–dipole interaction. With the increase of the collision energy, it is found that the splitting width remains the same (4 mGs), and that the resonance positions of s and p waves are shifted to higher magnetic fields with the increase of collision energy. The variations of the other quantities including the resonance width and the amplitude of the total scattering section are also discussed in detail. The thermally averaged elastic rate coefficients at T = 10, 15, 20, 25 K are calculated and compared.

Bandwidth Enhancement of Circular Ring Patch by Loading Single Split Complementary Split Ring Resonator

Metamaterials have gained a lot of interest in modern wireless devices due to their electromagnetic characteristics and it is employed to improve antenna parameters such as bandwidth, gain and efficiency. The study presents a novel strategy of single split non-uniform width Complementary Split Ring Resonator (CSRR) equipped Circular ring Microstrip Antenna (CRMA). The radiating element dimensions are seen to be 20 mm x 20 mm at the initial working frequency wherein the CSRR is incorporated on the ground plane of CRMA. The single split non-uniform width metamaterial (CSRR) structure displays -10 dB impedance bandwidth at 11.1 and 13.56 GHz which is beneficial for applications pertaining to X and Ku band. The total bandwidth of the said metamaterial antenna is 4 GHz (10.73-14.75). Optimization is undertaken with the help of commercially assessable simulation software tool Ansys HFSS 2019 version and practically measured using network analyzer. It is quite obvious from the experimentation that the results calculated get along well with the assumed outcomes.

Quasiparticle tunneling and 1/f charge noise in ultrastrongly coupled superconducting qubit and resonator

We report an experimentally observed anomalous doubly split spectrum and its split-width fluctuation in an ultrastrongly coupled superconducting qubit and resonator. From an analysis of Rabimodel and circuit model Hamiltonians, we found that the doubly split spectrum and split-width fluctuation are caused by discrete charge hops due to quasiparticle tunnelings and a continuous background charge fluctuation in islands of a flux qubit. During 70 hours in the spectrum measurement, split width fluctuates but the middle frequency of the split is constant. This result indicates that quasiparticles in our device seem mainly tunnel one particular junction. The background offsetcharge obtained from split width has the 1/f noise characteristic.

Characteristics of Left Handed Materials

Researchers have been interested in studying so-called Left-Handed Metamaterials LHM, which are artificial materials. These materials have unusual characteristics, like negative permittivity and permeability, and therefore negative index. This paper has been discussed some characteristics of LHM by designing a square split ring resonator SRR and simulating with CST microwave studio (Computer Simulation Technology) to get S-parameters. The broadband frequencies (0-30) GHz were taking to specify the effective range of frequencies to work with, which was found to be between (8- 14) GHz. Then, the parameters of SRR have been varied such as split width on, gap width, metal width, rod width and metal material. The measurements show some of parameters have been affected the values of resonance frequency and the others are not. Also, the negative values of permittivity, permeability, and refractive index have been approved.