bluuebunny/crossref_metadata_2025_split huggingface dataset:
Controlled single step synthesis, structural and electrode response of honeycomb layered Li3Co2SbO6
Authors: Singh Arvind , Chakrabarti Shamik , Nair Manjula G , Thakur A K 
Published: September 2024

Abstract
We report, for the first time, a single step synthesis process of Li3Co2SbO6 in air medium using the solid state reaction route. The structural analysis confirmed single phase layered crystal structure comprising 2D diffusion path along a-axis and b-axis. The Rietveld refinement of Li3Co2SbO6 yielded monoclinic crystal structure with C2/m space group having cell parameters, a = 5.216 A°, b = 8.989 A° and c = 5.171 A° with Li/Co mixed occupancy. The TEM analysis corroborated the layered structure which is consistent with x-ray analysis. Raman and FTIR analysis confirmed the presence of -CoO6 and -SbO6 octahedra in Li3Co2SbO6 with edge shared arrangement to form a layered stack comprising tunnel type pathway for Li+ ion transport. The estimated electrical conductivity of Li3Co2SbO6 is found to be ∼6.9 × 10−8 Scm−1 with a band gap ∼ 3.5 eV that suggests poor electronic transport for storage cells. This was observed in the electrochemical response of the Li || LiPF6(EC/EMC) || Li3Co2SbO6 cell. The 1st discharge capacity of Li3Co2SbO6 has been found to be a meagre 45 mAhg−1. Despite lower reversible capacity due to poor electrical transport, stable coulombic efficency observed up to 100 cycles suggest the feasibility of improvements in the electrical and charge transport properties.
The constancy of the speed of the light comes from the causality principle
Authors: Kim Do-Hyung 
Published: September 2024

Abstract
It is well-known that Einstein's relativity theory begins with a principle, the constancy of the speed of the light. However, the principle does not meet our usual, Galilean perspectives. Then, we can ask : What is the origin of the principle? What makes the speed of the light constant to everyone? In this work, it is argued that, in mathematically rigorous terms, the principle is almost equivalent to the local causality principle and this can be interpreted as ‘Even if time machine exists, it depends not on the local structure but on the global structure, or equivalently, on the topology of our universe.’ In mathematical terms, we show that any diffeomorphism between spacetimes is conformal if the diffeomorphism preserves pointwise harmonicity of functions.
High-sensitive MXene and GST-based tunable refractive index sensor for the infrared and visible spectrum from multipurpose sensing applications
Authors: Sbeah Zen A , Sorathiya Vishal , Alwabli Abdullah , Jaffar Amar Y , Aldosari Fahd M , Faragallah Osama S 
Published: September 2024

Abstract
In this paper, a sensor with a multi-layered structure based on MXene and chalcogenide which is based on germanium (Ge)-antimony (Sb) telluride (Te) (GST) as an active plasmonic material is designed. The design is simulated in 2D. The design is a general sensor to detect refractive index from 1 to 1.15. Here, the design structure is arranged by placing the analyte on top. The middle metal layer is considered Ag/Au/Al/Cu to identify the effect of the metal layer on overall absorption and reflector. The GST layer is modeled with two distinct states: aGST and cGST, allowing for the analysis of the structure's tunable behavior based on the varying properties of these states. Optimisation and validation for parameters like height, width, and other metals, such as Ag/Au/Cu/Al processes, were conducted to ensure optimal device performance. The proposed refractive index sensor offers a high sensitivity variation ranging from 80 deg RIU−1 to 770 deg/RIU. The bandwidth and resonant area show significant variation between the two states of GST material. In other words, the proposed refractive index sensor can be used as a lab-on-chip biosensor. This proposed sensor provides potential application in the research of biomolecular detection and chemical testing.
Tuning the IcRn value of YBCO step edge Josephson junction through Ar+ ion irradiation
Authors: Kumar Sandeep , Khare Neeraj 
Published: September 2024

Abstract
YBCO Step edge Josephson junctions are fabricated on single crystal MgO (100) substrates, and the effect of Ar+ ion irradiation on the critical current (Ic) and normal state resistance (Rn) is studied. It is shown that on the appropriate exposure of the YBCO step edge junction to Ar+ ion irradiation, the IcRn product of the junction can be enhanced up to 0.66 mV at 77 K, which is sufficiently good for many applications. With the increase in the exposure time of Ar+ ion irradiation, the value of Ic decreases, and the Rn value increases. After irradiating for 4 min, Ic as low as 70 μA and Rn as high as ∼9.4 Ω have been obtained at 77 K. It is found that for higher exposure time, the junction behavior tends to SIS-type junctions. The mechanism responsible for the decrease in Ic and increase in Rn seems to be associated with the vacancies as well as displacement of oxygen atoms caused by the ion irradiation, which causes the suppression of superconducting parameters as the superconducting properties critically depend on the concentration of the oxygen atoms in the Cu-O planes.
Spectral prediction of all dielectric nanopore metasurface based on DBO-DNN model
Authors: Chen Ying , Li Weiqiang , Wang Qinghui , Zhao Guoting , Shi Moqing 
Published: September 2024

Abstract
Based on the optical properties of symmetric structures independent of each other in the orthogonal direction, a class of all-dielectric nanohole array metasurfaces symmetrical along the diagonal is designed. By adding nanopores of different shapes to break the symmetry of the periodic unit structure, the double Fano resonance is excited. The spectral characteristics of metasurfaces with the same structure type are studied by finitedifference timedomain (FDTD) method. The deep neural network (DNN) is used to establish the nonlinear mapping relationship between the input structural parameters and the transmission spectrum. The number of hidden layers in the DNN and the number of neurons in each layer are optimized by the dung beetle optimization (DBO) algorithm. Therefore, the number of hidden layers of the model is determined to be 5, and the number of neurons in each layer is 120, 30, 150, 60, 90, respectively. The mean square error (MSE) is used to evaluate the training effect of DNN after optimization search. After 35,000 epochs of training, MSE is reduced to 0.0003926. The influence of different gradient descent optimization algorithms on the prediction results is explored respectively, and it is found that Adamax is the most effective. The results show that the prediction model can predict the spectrum within 1 s. Compared with the traditional simulation method, the simulation time is effectively saved. Meet the requirements of efficient and rapid design of ultra-thin lenses. For the same type of metasurface structure, the transmission spectrum can be accurately predicted without multiple data sets.
Graphene-based hybrid metasurfaces with quasi-bound states in the continuum for manipulating terahertz absorption
Authors: Wang Baoku , Wang Feng , Tian Fengjun , Li Li 
Published: September 2024

Abstract
We present a graphene-based hybrid metasurface with quasi-bound states in the continuum (BICs) for manipulating terahertz (THz) wave absorption. By the strategic application of structural perturbations for the THz metasurface, the symmetry-protected BICs transforms into quasi-BICs. The incorporation of graphene adeptly satisfies the critical coupling condition, thereby facilitating the attainment of the theoretical maximum absorption of 0.5 for the quasi-BICs in the THz region. And the Q-factor of the quasi-BIC can be up to 2755. Moreover, the metasurface exhibits a distinctive ability for unique tuning and efficient absorption of terahertz waves by varying the asymmetry parameter and Fermi levels. This work provides promising strategies for manipulating terahertz wave absorption.
(Pseudo-)Synthetic BRST quantisation of the bosonic string and the higher quantum origin of dualities
Authors: Patrascu Andrei T 
Published: September 2024

Abstract
In this article I am arguing in favour of the hypothesis that the origin of gauge and string dualities in general can be found in a higher-categorical interpretation of basic quantum mechanics. It is interesting to observe that the Galilei group has a non-trivial cohomology, while the Lorentz/Poincare group has trivial cohomology. When we constructed quantum mechanics, we noticed the non-trivial cohomology structure of the Galilei group and hence, we required for a proper quantisation procedure that would be compatible with the symmetry group of our theory, to go to a central extension of the Galilei group universal covering by co-cycle. This would be the Bargmann group. However, Nature didn’t choose this path. Instead in nature, the Galilei group is not realised, while the Lorentz group is. The fact that the Galilei group has topological obstructions leads to a central charge, the mass, and a superselection rule, required to implement the Galilei symmetry, that forbids transitions between states of different mass. The topological structure of the Lorentz group however lacks such an obstruction, and hence allows for transitions between states of different mass. The connectivity structure of the Lorentz group as opposed to that of the Galilei group can be interpreted in the sense of an ER=EPR duality for the topological space associated to group cohomology. In string theory we started with the Witt algebra, and due to similar quantisation issues, we employed the central extension by co-cycle to obtain the Virasoro algebra. This is a unique extension for orientation preserving diffeomorphisms on a circle, but there is no reason to believe that, at the high energy domain in physics where this would apply, we do not have a totally different structure altogether and the degrees of freedom present there would require something vastly more general and global.
Aging characterization of dielectric materials using microstrip spiral resonator sensor: application in high frequency range, up to 18 GHz
Authors: Bensahla Naziha , Amar Hichem , Amir Mounir , Tebache Soufiane , Hedir Abdallah 
Published: September 2024

Abstract
This current work aims to propose a complete microwave procedure for dielectric materials aging characterization. To achieve this aim, a microstrip spiral resonator sensor, based on printed circuit board (PCB) technology, is designed to attend polyvinyl chloride (PVC) aging behavior through microwave measurements. The resonator is composed of a spiral microstrip, excited by coupling 50-Ohm transmission line on the top layer of the substrate; meanwhile a rectangular slot is etched in the bottom layer, behind the spiral shape to achieve high inductive effect. Structure optimization was conducted using high-frequency structure simulator (HFSS). The sensor is then used as a holder of the UV-aged PVC material while reflection (S11) and transmission (S21) coefficients are measured by vector network analyzer (VNA) in high frequency range, up to 18 GHz. The aging effect is finally perceived by observing the frequency shift of the resonance frequency between the empty and the aged-PVC loaded sensor, together with a variation in the S21 parameter amplitude. It is then found that for 864 h of UV-exposure is provided more than 0.45% frequency shift and about 4.67% decrease in electromagnetic energy transmission. Moreover, comparison between S11 and S21 results reveals that using S11 parameter is more practical to investigate material aging as it allows for simple visual checking of the frequency shift.
A new spline method on graded mesh for fourth-order time-dependent PDEs: application to Kuramoto-Sivashinsky and extended Fisher-Kolmogorov equations
Authors: Sharma Sachin , Sharma Naina 
Published: September 2024

Abstract
In this research, we introduce a two-tier non-polynomial spline approach with graded mesh discretization for addressing fourth-order time-dependent partial differential equations, which find applications in various physical scenarios like the nonlinear Kuramoto-Sivashinsky equation and extended Fisher-Kolmogorov equation. Our method involves considering three spatial points at each time step for scheme development, achieving spatial accuracy of three and temporal accuracy of two. Notably, our approach offers the advantage of directly tackling singular biharmonic problems without the need for discretizing boundary conditions or incorporating fictitious points. It demonstrates unconditional stability when tested on fourth-order problems and outperforms previous methods, as evidenced by comparative analyses. Additionally, we present 2D and 3D plots illustrating numerical solutions for different benchmark scenarios, including the depiction of the chaotic nature of the Kuramoto-Sivashinsky equation under Gaussian initial conditions at various time levels.
Statistical analysis of Cu content effects on structural properties in CuZr metallic glasses
Authors: Amigo Nicolás 
Published: September 2024

Abstract
This study examines the effects of casting conditions on the structural properties of CuZr metallic glasses (MGs) using molecular dynamics simulations. The influence of Cu content on various structural properties was explored, finding significant power-law relationships that indicate increased Cu promotes the formation of icosahedra-like structures and enhances the population of solid-like polyhedra. In contrast, the clustering coefficient, reflecting solid-like connectivity, showed a linear relationship with Cu content, revealing that while Cu increases solid-like structures, their connectivity does not scale proportionally. No significant correlations were found for sample volume, cooling rate, or temperature within the studied ranges. This study highlights the utility of statistical analysis in elucidating material property relationships, contrasting with the less interpretable nature of machine learning models. The findings provide valuable insights into the role of Cu content in MGs and demonstrate the importance of traditional statistical approaches for material characterization.
Achieving beyond 30% efficiency for hole-transport-layer-free CsSnI3 perovskite solar cell: a comprehensive simulation study
Authors: Ullah Saad , ul Ain Qurat , Qamar Samina , Khan Firoz , Khan Mohd Taukeer 
Published: September 2024

Abstract
In recent years, the growing significance of lead-free CsSnI3 perovskite can be credited to its outstanding optoelectronic properties and environmentally friendly nature. Nevertheless, the photovoltaic potential of CsSnI3 is limited due to challenges in achieving defect-free device structures. The current study thoroughly analyzed the performance of CsSnI3-based perovskite solar cells (PSCs) using the SCAPS-1D software. An in-depth investigation was performed on multiple physical parameters, including the thickness of perovskites layer, acceptor density (NA), operating temperature, defect densities, shunt resistance (RSh) and series resistance (RS). This comprehensive study aimed to identify the optimal device configuration that yields the highest power conversion efficiency (PCE) for the hole-transport-layer (HTL)-free CsSnI3-based PSCs. The obtained results confirmed that it is crucial to decrease the number of defects (Nt) at the perovskites/electron transport layer (ETL) interface to improve the efficiency of CsSnI3-based PSCs. The optimized device demonstrated exceptional performance, achieving an open-circuit voltage (VOC) of 1.12 V, a fill factor (FF) of 85.08%, a short-circuit current density (JSC) of 33.29 mA cm−2 and an efficiency of 31.87%. This high efficiency simulated result provide valuable insights into the design of high-performance CsSnI3-based PSCs, paving the way for potential breakthroughs in cost-effective and eco-friendly solar energy technologies.
Millimeter wave frequency generation based on variations in coupling coefficients of a silicon add-drop microring resonator
Authors: Katti Rohan , Prince Shanthi 
Published: September 2024

Abstract
A microwave photonic system with silicon add-drop microring resonator as the core photonic device is analyzed for microwave/millimeter wave frequency generation. The primary concept of the proposed study relies on varying the coupling coefficients of the silicon add-drop microring resonator. Unequal coupling coefficients between the ring cavity and bus waveguides are one of the parameters which are responsible for generating second, third order sidebands in the radio frequency spectrum generated at the photodetector. Another parameter of interest is the phase difference between the two radio frequency signals which are fed to the Mach–Zehnder modulators of the proposed system. A 1 GHz sinusoidal signal with 1V peak-to-peak amplitude results in a third order sideband generation whose frequency corresponds to 3 GHz. The coupling coefficients in this case are 0.2 and 0.8, between ring cavity, top and bottom waveguides respectively. It is also observed that, phase difference of 90◦ between the input radio frequency signals results in highest power of the third order sideband generated in the output radio frequency spectrum whose frequency corresponds to the multiple of input radio frequency.
Axion dark matter with explicit Peccei-Quinn symmetry breaking in the axiverse
Authors: Li Hai-Jun 
Published: September 2024

Abstract
It was shown that the required high quality of the Peccei-Quinn (PQ) symmetry can be a natural outcome of the multiple QCD axions model.
In the axiverse, a hypothetical mass mixing between the QCD axions and axion-like particles (ALPs) can occur, which leads to an interesting phenomenon called the level crossing.
In this paper, we investigate this mass mixing between one QCD axion and one ALP with the explicit PQ symmetry breaking in the early Universe.
The dynamics of the axions and their cosmological evolutions when the level crossing occurs in this scenario are studied in detail.
We show the evolution of the mass eigenvalues and the mass mixing angle.
Then we check the condition for energy adiabatic transition with the corresponding parameter set.
Finally, we estimate the relic density of the QCD axion and ALP dark matter through the misalignment mechanism.
We find that, the QCD axion relic density can be suppressed, while the ALP relic density can be enhanced.
The level crossing in our scenario may have some cosmological implications, such as the axion domain walls formation, the nano-Hertz gravitational waves emission, and also the primordial black holes formation.
Group frames via magic states with applications to SIC-POVMs and MUBs
Authors: Feng Lingxuan , Luo Shunlong 
Published: September 2024

Abstract
We connect magic (non-stabilizer) states, symmetric informationally complete positive operator valued measures (SIC-POVMs), and mutually unbiased bases (MUBs) in the context of group frames, and study their interplay. Magic states are quantum resources in the stabilizer formalism of quantum computation. SIC-POVMs and MUBs are fundamental structures in quantum information theory with many applications in quantum foundations, quantum state tomography, and quantum cryptography, etc. In this work, we study group frames constructed from some prominent magic states, and further investigate their applications. Our method exploits the orbit of discrete Heisenberg–Weyl group acting on an initial fiducial state. We quantify the distance of the group frames from SIC-POVMs and MUBs, respectively. As a simple corollary, we reproduce a complete family of MUBs of any prime dimensional system by introducing the concept of MUB fiducial states, analogous to the well-known SIC-POVM fiducial states. We present an intuitive and direct construction of MUB fiducial states via quantum T-gates, and demonstrate that for the qubit system, there are twelve MUB fiducial states, which coincide with the H-type magic states. We compare MUB fiducial states and SIC-POVM fiducial states from the perspective of magic resource for stabilizer quantum computation. We further pose the challenging issue of identifying all MUB fiducial states in general dimensions.
Characterization of highly radiating nitrogen-seeded H-mode plasmas in unfavorable BT at ASDEX Upgrade
Authors: Chen L. , Wolfrum E. , Pan O. , Kurzan B. , Bernert M. , Brida D. , Cavedon M. , Dux R. , Fischer R. , Griener M. , Grover O. , Plank U. , Stieglitz D. , Zito A. ,   the ASDEX Upgrade Team
Published: September 2024

Abstract
The highly radiating nitrogen-seeded H-mode plasmas in unfavorable BT
has been characterized in the ASDEX Upgrade tokamak (AUG). Three levels of nitrogen puffing rates have been injected into a fully detached H-mode plasma, which is run in lower single null configuration with the ion

B
×
∇
B

drift away from the X-point. A cold (

∼

1
−
2

eV) highly radiating (

∼

13.0

MW

m

−
3

) region forms close to the X-point immediately after nitrogen seeding, as evidenced by measurements of the divertor Thomson scattering (DTS) and the two-dimensional bolometry reconstructions. In addition, the radiator moves further upwards above the X-point along the separatrix at the high-field side (HFS) with increasing nitrogen puffing rates, as evidenced by the Absolute eXtended UltraViolet (AXUV) measurements. The formation of the highly radiating regime is closely correlated to the modifications of the divertor plasma conditions. Along the line of sight of the DTS measurement, the electron temperature reduces down to a few eV, which initials near the X-point and further extends to the HFS scrape-off layer (SOL) simultaneously with the upward movement of the radiator, however, the electron temperature sustains (

∼

30
−
50

eV) at the low-field side (LFS) SOL with slightly decreased electron density. The highly radiating regime shows LFS/HFS divertor asymmetry, in contrast to that for H-mode plasmas in favorable BT
, suggesting that the drifts play an important role for the formation of the highly radiating X-point regime at AUG. The neutral particle flux increases significantly (factor of

∼

2

) in the private flux region, while it increases slightly (

<

20
%

) in the main chamber, thus suggesting an enhanced sub-divertor neutral compression with the formation of the highly radiating regime. Furthermore, a degradation of the pedestal electron density was observed with an enhancement of the electron temperature further inside the pedestal, and complete divertor detachment was achieved by nitrogen seeding with sustained plasma confinement. Finally, particle sources and flow patterns of deuterium and nitrogen ions have been analyzed by SOLPS-ITER modelling, confirming that the

E

×

B

drift plays an important role for the formation of the highly radiating regime in unfavorable BT
at AUG.