bluuebunny/crossref_metadata_2025_split huggingface dataset:
Spatiotemporal modulation of ultrafast plasmonic vortices with spin–orbit coupling
Authors: Li Weipeng , Zhang Shuoshuo , Zhou Zhangyu , Fu Yanan , Zhang Yuquan , Yuan Xiaocong , Min Changjun 
Published: April 2024

Abstract
The vortex field of surface plasmon polariton with orbital angular momentum (OAM), called plasmonic vortex, has played an important role in various research fields. However, the spatiotemporal properties of plasmonic vortex pulses excited by ultrafast laser, especially the dynamics of spin‒orbit coupling in the ultrafast plasmonic vortex field, have yet to be investigated deeply. Here, we study the spatiotemporal modulation of ultrafast plasmonic vortices with spin‒orbit coupling, using both analytical and simulation methods. The ultrafast plasmonic vortices are excited by a ring-shaped plasmonic lens, with an incident light composed of two time-delayed femtosecond sub-pulses carrying the same OAM but orthogonal circular polarizations. The dynamics of time-varying electric field, energy flow and angular momentum distributions of the plasmonic vortices are demonstrated, revealing details of the spin‒orbit coupling in spatiotemporal domain, such as the merging of multiple phase singularities with energy flow loops, and the variation of spin/orbital angular momentum per photon over time. This work could deepen the understanding of spin‒orbit coupling in plasmonic field and provide new ideas for ultrafast on-chip optical information processing.
Contribution of different electron-capture mechanisms in the fragmentation of CO

2

3
+

upon slow ion-molecule collisions
Authors: Kumar Kamal , Kalam Azad Siddiki Md Abul , Mukherjee Jibak , Singh Harpreet , Misra Deepankar 
Published: April 2024

Abstract
We present a recoil ion—projectile ion coincidence study on the three body fragmentation of

CO
2

3
+

ion into

C
+

+

O
+

+

O
+

fragments upon impact with

Ar

3
+

,

Ar

6
+

and

Ar

8
+

projectile ions having the same velocity of

v
p

=
0.49

a.u. (atomic units) using the recoil ion momentum imaging technique. The kinetic energy release (KER) distributions are presented and the effect of different electron-capture associated processes such as pure capture, electron capture followed by target-ionization or projectile auto-ionization is discussed based on the analysis of KER corresponding to different final projectile charge states post-collision. As the capture stabilization increased, the relative yields in the KER distribution are found to decrease in the high KER side for low charged

Ar

3
+

impact, while an increase is observed for

Ar

6
+

and

Ar

8
+

impacts. We discuss the interplay between electron-capture, projectile auto-ionization, and target ionization for the dominance of a particular process. We also observe a low-KER feature around 15 eV which was observed for electron and proton impacts, that has not yet been observed for highly charged ion impacts.
Particle transport along the circular trajectory of a semi-infinite Bessel acoustic beam
Authors: Zhou Qinxin , Ren Xuemei , Shi Yubo , Xu Zheng 
Published: April 2024

Abstract
We explored the propagation of semi-infinite accelerating Bessel beams along circular trajectories beyond the paraxial approximation. Until now, the complex nature of these beams has posed a challenge for the development of construction methods, resulting in primarily theoretical research within the field of acoustics. In this study, we successfully achieved experimental realization of these beams in the acoustic domain using our previously proposed acoustic Fourier transform system, which involves phase modulation through a holographic lens and Fourier transformation through a cylindrical focusing reflector. Our results demonstrate that these beams exhibit accelerated propagation along circular trajectories. Moreover, we experimentally generated and directly observed these highly curved beams during the transportation of micro-particles, where they undergo substantial bending at large angles.
Color image encryption algorithm based on novel dynamic DNA encoding and chaotic system*
Authors: Mou Dingkang , Dong Yumin 
Published: April 2024

Abstract
To enhance the security of image data, prevent unauthorized access, tampering, and leakage, maintain personal privacy, protect intellectual property rights, and ensure the integrity of images during transmission and storage. This study introduces an innovative color image encryption scheme based on dynamic DNA encoding operations and chaotic systems. By simulating a quantum random walk, a random key is generated to enhance the security of the confidential system. In addition, we integrated the enhanced Josephus problem into DNA coding rules to create dynamic DNA coding rules. At the same time, we proposed a dynamic double-loop DNA XOR operation, which fully utilizes the random sequence generated by the generalized Hamiltonian chaos system to precisely control the loop direction, starting point, and number of operations. This enhances the complexity of the encryption algorithm. After sufficient experimental verification and in-depth research and analysis, our innovative design not only enhances the difficulty of cracking while ensuring image quality but also provides reliable protection for the security of image data.
Enhanced smartphone connectivity: dual-band MIMO antenna with high isolation and low ECC
Authors: Abubakar Hassan Sani , Zhao Zhiqin , Munir Mehr E , Tareen Wajahat Ullah Khan , Wang Boning , Kiani Saad Hassan , Ali Tanweer 
Published: April 2024

Abstract
The research presents an eight-element dual-band modified T-shaped slot antenna array optimized for seamless integration into contemporary smartphones, addressing the burgeoning demands of 5G communication within the sub-6 GHz spectrum. Operating across two critical frequency bands spanning 3.37-3.61 GHz and 4.9-5.1 GHz, this advanced antenna system boasts impressive efficiency and performance metrics. Symmetrically arranged on the ground plane, each antenna element measures 20 × 11.8 mm2 (equivalent to 0.233 λ×0.138λ), with a notable design feature being the inclusion of section Dx, strategically positioned between the ground-mounted antennas to enhance isolation among radiating elements by effectively managing surface currents. Fabrication results showcase isolation levels surpassing -14 dB, with an Envelope Correlation Coefficient (ECC) lower than 0.05 in the lower frequency band and 0.02 in the higher band, indicating robust performance in mitigating mutual coupling effects. The antenna array exhibits exceptional efficiency ranging from 48.5% to 63.7%, coupled with a commendable channel capacity of 38.8 bps/Hz and a gain of 3.9 dBi, highlighting its suitability for integration into smartphone devices and its potential to advance the next generation of mobile communication technologies.
Enhanced self-collimation effect by low rotational symmetry in hexagonal lattice photonic crystals
Authors: Yuksel Zekeriya M , Oguz Hasan , Karakilinc Ozgur O , Turduev Mirbek , Berberoglu Halil , Adak Muzaffer , Ozdemir Kart Sevgi 
Published: April 2024

Abstract
In this study, we present the design of a photonic crystal (PC) structure with a hexagonal lattice, where adjustments to the PC unit cell symmetry reveal an all-angle self-collimation (SC) effect. By optimizing opto-geometric parameters, such as the rotational angle of auxiliary rods and adjacent distances, we analyze the SC property in detail, leveraging group velocity dispersion (GVD) and third-order dispersion (TOD) characteristics. We also investigate the relationship between symmetry properties and their influence on dispersion characteristics. Through symmetry manipulation, we gain a comprehensive understanding of the underlying mechanisms governing light collimation and confinement in the proposed configurations. The PC structure with a C1 symmetry group exhibits all-angle SC effect within the range of a/λ = 0.652 and a/λ = 0.668 normalized frequencies, with a bandwidth of Δω/ω

c

=2.4% Further breaking the symmetry, transforming from C1 to C2 group symmetry enhances the SC bandwidth to Δω/ω

c

=6.5% and reveals the perfect linear equi-frequency contours (EFC) at two different frequency bands: all angle SC between a/λ = 0.616 and a/λ = 0.344 normalized frequencies in the 4th transverse magnetic (TM) band and between a/λ = 0.712 and a/λ = 0.760 in the 5th TM band. Here, GVD and TOD values of the TM 4th band vary between 7.3 (a/2πc2)–254.3 (a/2πc2) and 449.2 (a2/4π
2c3)–1.3×105 (a2/4π
2c3), respectively. Also, GVD and TOD values of the TM 5th band vary between 182.5 (a/2πc2)–71.3 (a/2πc2) and −24380(a2/4π
2c3)–−9619 (a2/4π
2c3) values, respectively. Additionally, we propose a composite/hybrid PC structure resembling C2 group symmetry, where two auxiliary rods are replaced by rectangular photonic wires with the same refractive index and width equal to the diameter of auxiliary rods. This hybrid structure exhibits an all-angle SC effect with an operating bandwidth of Δω/ω

c

=11.7%, which displays near-zero GVD and TOD performance and offers enhanced robustness against potential fabrication precision issues.
Theoretical prediction of soft-forming micro-hemispherical shells from fused silica substrates in reclining mold
Authors: Yang Xiuhua , Xia Dunzhu , Li Jinhui , Chu Qingbo 
Published: April 2024

Abstract
A reclining mold can support the soft forming of fused silica substrates into micro-hemispherical shells with the same height, which makes the processing of micro-hemispherical shells attractive. Currently, it is difficult to determine the optimal process parameters for machining micro-hemispherical shells, and several iterations of experiments are required. This process wastes large amounts of substrate material, experimental consumables, and machining time, and increases the cost of the experiments. In this paper, we report a reflow process for soft-forming micro-hemispherical shells from fused silica substrates supported by a reclining mold. The shapes of the shells formed from the fused silica substrates in reclining and non-reclining molds were analysed by building a two-dimensional model. Moreover, we predicted the effects of varying the process parameters on the shell-forming time and geometrical parameters, as well as the stresses and deformations of the shells after cooling. The effect of the eccentricity of the central support column of the mold on the symmetry of micro-hemispherical shells was also investigated, and the influence of the mold and substrate heating inhomogeneity on micro-hemispherical shell formation was analysed. Additionally, the heat uniformity of the substrate in the rotating state was examined. Finally, we investigated the temperature field and thickness distribution during the shell-forming process through 3D modelling to verify the 2D modelling results. Analysing and predicting the parameters helps to reduce the number of trial-and-error processes in experiments, and we expect this work to provide a theoretical parametric basis for micro-hemispherical shell machining.
Corrigendum: Dynamic Hubbard model: kinetic energy driven charge expulsion, charge inhomogeneity, hole superconductivity, and Meissner effect (2013 Phys. Scr.
88 035704)
Authors: Hirsch J E 
Published: April 2024

Abstract
The paper erroneously stated that inflowing electrons in the Meissner effect transmit momentum to the body through collisions.
Experimental study of hydraulic lifting platform based on multi-ring disc magnetorheological valve
Authors: Cao Zhiqiang , Xie Guojin , Huang Yinyan , Han Leigang , Yang Xiaolong 
Published: April 2024

Abstract
To enhance the operational capabilities of a hydraulic lifting apparatus, a hydraulic lifting platform was engineered based on a multi-ring disc magnetorheological valve. The pressure drop characteristics of the multi-ring disc magnetorheological valve were determined through theoretical analysis, supplemented by magnetic field simulations to assess its performance. The effects of different currents on the stability and response time of the hydraulic lifting platform are studied, and the control accuracy of the hydraulic lifting platform position is verified. The results show that the saturation current of the magnetorheological valve is 2.5 A. The addition of current to the magnetorheological valve leads to a rapid increase in both actuator speed and acceleration, which then levels off. Similarly, the response time of the actuator decreases with an increasing current until it stabilizes. At a coil current of 1.5 A, the actuator achieves a speed of approximately 86 mm s−1, an acceleration of approximately 105 mm s−2, and a response time of approximately 7.15 s. Furthermore, the lifting position accuracy of the hydraulic lifting platform is ±1 mm.
Insights into optoelectronic, thermodynamic, and thermoelectric properties of novel GePtCh (Ch = S, Se, Te) semiconductors: first-principles perspective
Authors: Salman Khan Muhammad , Gul Banat , Benabdellah Ghlamallah , Ahmad Bashir , Alotaibi Nouf H , Mohammad Saikh , Ahmad Hijaz 
Published: April 2024

AbstractTernary chalcogenides are often studied for their remarkable heat resistance and flexible optical properties. We used density functional theory and examine complicated connections between the various physical features of the exclusive GePtCh (Ch = S, Se, and Te) ternary chalcogenides. The valence band is formed by the hybridization of the Ge-s/p/d, Pt-s/p/d, S-p, Se-p, and Te-p orbitals in the energy range of −6.0 eV to 0 eV. The materials under consideration are confirmed as indirect bandgap materials with estimated energy gaps of 1.29 eV, 0.86 eV, and 0.48 eV, respectively. By substituting Se and Te for S reduced the bandgap in these materials. The complex dielectric function’s components, absorption coefficients, real optical conductivity, energy loss functions, refractive index, reflectivity, and extinction coefficient, are studied and examined to identify their potential use in optoelectronic applications. The thermodynamic parameters of these ternary systems are calculated by employing the quasi-harmonic Debye model. The materials are suitable for thermoelectric devices, as evidenced by their considerable and outstanding thermoelectric features. The GePtTe possessed the highest absorption, indicating that it is a suitable material for the use in optoelectronic applications.
Slots and stubs incorporated annular ring-shaped compact microstrip antenna with circular polarization characteristics for wireless UWB communication systems
Authors: El-Arrouch Tarik , Das Sudipta , Islam Tanvir , Sorathiya Vishal , Madhav Boddapati Taraka Phani , El Ansari Abdelaaziz , El Amrani El Idrissi Najiba 
Published: April 2024

Abstract
A circularly polarized (CP) antenna with ultra-wideband resonance and a broad axial ratio bandwidth is designed for UWB communication systems. The prescribed design comprises of a modified annular ring-shaped radiator and a modified step-graded slots loaded partial ground plane. The projected antenna is prototyped on FR4 substrate of 35 × 30 × 1.6 mm3. To achieve wide axial ratio bandwidth, a rectangular vertical slot is inserted into the radiating patch and two stubs are embedded into the monopole ground plane, which is configured with step graded rectangular slots. The simulation results are verified by testing the fabricated protype. The proposed design operates at UWB spectrum with an ultra-wide impedance bandwidth (IBW) of 134.57%, centered at 10.7 GHz, covering 3.5 GHz to 17.9 GHz frequency spectrum. Furthermore, it demonstrates circular polarization characteristics with a broad axial ratio bandwidth (ARBW) of 96.29% expanding from 3.5–10 GHz (6500 MHz). Its peak gain reaches to 8.7 dBi and a maximum radiation efficiency of 95% is achieved within the operating band. The results (measured and simulated) obtained in terms of S11, axial ratio, gain and efficiency and radiation patterns exhibit high agreement. The presented antenna could be a suitable choice for 5.5 GHz Worldwide Interoperability for Microwave Access (Wi-Max), 5.2/5.8 GHz Wireless local area network (WLAN), X-band satellite communication (downlink: 7.25–7.745 GHz, uplink: 7.9–8.4 GHz), UWB communication systems, and other applications in microwave C, X, Ku bands due to its superior characteristics.
Optimizing the noise control in a two-layer conduit
Authors: Shafique Sajid , Arsalan Ahmad Muhammad , Afzal Muhammad 
Published: April 2024

Abstract
In the modern world, noise pollution is a major concern due to its prevalence. This work focuses on optimizing noise control in a two-layer conduit. A conduit comprises an inlet and double-outlet zones (DOZ). The upper walls of the DOZ are lined with perforated absorbent material while the lower walls are layered with fibrous. Mathematically, the physical problem is formulated with a field wave equation together with rigid and impedance boundary conditions in the respective zones. Such governing boundary value problem (BVP) leads to the Sturm-Liouville (SL) category in which standard orthogonality relations (OR) are indispensable. The system of the linear equations of the BVP is acquired with semi-analytical Mode-Matching (MM) approach by implementing the continuity conditions of sound pressures and velocities at the matching junction with the aid of OR. These systems are truncated and solved numerically with computation learning to obtain the reflected and transmitted modal amplitudes in respective zones. Due to the lining's perforated upper walls, fibrous lower walls, and reversal in the DOZ, the analysis of the reflected and transmitted powers versus frequencies is significantly observed and is shown in graphical findings. The algebraic derivation is validated by satisfying the conservation law of power flux and matching continuity conditions for impedance, perforated, and fibrous lined boundaries.
A multi-mode free-space delay interferometer with no refractive compensation elements for phase-encoded QKD protocols
Authors: Tretiakov V V , Kravtsov K S , Klimov A N , Kulik S P 
Published: April 2024

Abstract
We demonstrate a compensation-free approach to the realization of multi-mode delay interferometers, mainly for use in phase-encoded quantum key distribution (QKD). High interference visibility of spatially multi-mode beams in unbalanced Michelson or Mach–Zehnder interferometers with a relatively wide range of delays is achieved by the appropriate choice of the transverse size of the beam. We provide a simple theoretical model that gives a direct connection between the visibility of interference, the delay and the beam parameters. The performed experimental study confirms our theoretical findings and demonstrates measured visibility of up to 0.95 for a delay of 2 ns. Our approach’s simplicity and robust performance make it a practical choice for the implementation of QKD systems, where a quantum signal is received over a multi-mode fiber. The important application of such a configuration is an intermodal QKD system, where the free-space atmospheric communication channel is coupled into a span of the multi-mode fiber, delivering the spatially distorted beam to the remote receiver with minimal coupling loss.
Large dynamic range digital delay with sub-picosecond precision
Authors: Dehmeshki Diba , Eberle Zachariah , Frahm Erich , Rusack Roger , Saradhy Rohith , Tousi Yahya 
Published: April 2024

Abstract
We report on the development and performance of a digitally controlled phase delay with a step of 280 femtoseconds and a dynamic range of 230 picoseconds. Details of the device design and the simulations as well as comparisons with laboratory measurements will be discussed. We describe how we have used this ASIC to stabilize a digital clock to a precision of less than one picosecond.
Construction and evaluation of a large radiation detector for Positron Emission Tomography applications
Authors: Raylman R.R. , Stolin A.V. , Jaliparthi G. , Martone P.F. 
Published: April 2024

Abstract
Large arrays of pixelated scintillator potentially have
application in economical construction of PET scanners. In this
investigation, we constructed and evaluated a detector with an
active area of 32.26 × 13.47 cm2. It is based on a
218 × 91 array of 1.4 × 1.4 × 15 mm3 LYSO
elements (pitch 1.48 mm). Scintillation light is detected with a
5 × 12 array of silicon photomultipliers (SiPM) arrays. Each
array consists of an 8 × 8 array of 3 × 3 mm2
(pitch 3.35 mm) SiPMs. Performance of these devices are enhanced
and stabilized by cooling them. Testing revealed that the detector
was able to detect 90% of the theoretically detectable 511 keV
photons. The resolvability index (a measure of the ability to
identify individual detector elements from background) is
0.24 ± 0.04. Additionally, the average energy resolution for the
complete detector is 18.3%. These results compare well with those
reported for much smaller detector modules.
Charge amplification in sub-atmospheric CF4:He mixtures for directional dark matter searches
Authors: McLean A.G. , Spooner N.J.C. , Crane T. , Eldridge C. , Ezeribe A.C. , Marcelo Gregorio R.R. , Scarff A. 
Published: April 2024

Abstract
Low pressure gaseous Time Projection Chambers (TPCs) are a
viable technology for directional Dark Matter (DM) searches and have
the potential for exploring the parameter space below the neutrino
fog [1,2]. Gases like CF4 are advantageous
because they contain flourine which is predicted to have heightened
elastic scattering rates with a possible Weakly Interacting Massive
Particle (WIMP) DM candidate [3,4,5]. The
low pressure of CF4 must be maintained, ideally lower than
100 Torr, in order to elongate potential Nuclear Recoil (NR) tracks
which allows for improved directional sensitivity and NR/Electron
Recoil (ER) discrimination [6]. Recent evidence suggests
that He can be added to heavier gases, like CF4, without
significantly affecting the length of 12C and 19F recoils
due to its lower mass. Such addition of He has the advantage of
improving sensitivity to lower mass
WIMPs [1]. Simulations can not reliably predict
operational stability in these low pressure gas mixtures and thus
must be demonstrated experimentally. In this paper we investigate
how the addition of He to low pressure CF4 affects the gas gain
and energy resolution achieved with a single Thick Gaseous Electron
Multiplier (ThGEM).