bluuebunny/crossref_metadata_2025_split huggingface dataset:
Characterization of partially accessible anisotropic spin chains in the presence of anti-symmetric exchange
Authors: Cavazzoni Simone , Adani Marco , Bordone Paolo , Paris Matteo G A 
Published: May 2024

Abstract
We address quantum characterization of anisotropic spin chains in the presence of anti-symmetric exchange, and investigate whether the Hamiltonian parameters of the chain may be estimated with precision approaching the ultimate limit imposed by quantum mechanics. At variance with previous approaches, we focus on the information that may be extracted by measuring only two neighboring spins rather than a global observable on the entire chain. We evaluate the Fisher information (FI) of a two-spin magnetization measure, and the corresponding quantum Fisher information (QFI), for all the relevant parameters, i.e. the spin coupling, the anisotropy, and the Dzyaloshinskii–Moriya (DM) parameter. Our results show that the reduced system made of two neighboring spins may be indeed exploited as a probe to characterize global properties of the entire system. In particular, we find that the ratio between the FI and the QFI is close to unit for a large range of the coupling values. The DM coupling is beneficial for coupling estimation, since it leads to the presence of additional bumps and peaks in the FI and QFI, which are not present in a model that neglects exchange interaction and may be exploited to increase the robustness of the overall estimation procedure. Finally, we address the multiparameter estimation problem, and show that the model is compatible but sloppy, i.e. both the Uhlmann curvature and the determinant of the QFI matrix vanish. Physically, this means that the state of the system actually depends only on a reduced numbers of combinations of parameters, and not on all of them separately.
Thermodynamically consistent flocking: from discontinuous to continuous transitions
Authors: Agranov Tal , Jack Robert L , Cates Michael E , Fodor Étienne 
Published: May 2024

Abstract
We introduce a family of lattice-gas models of flocking, whose thermodynamically consistent dynamics admits a proper equilibrium limit at vanishing self-propulsion. These models are amenable to an exact coarse-graining which allows us to study their hydrodynamic behavior analytically. We show that the equilibrium limit here belongs to the universality class of Model C, and that it generically exhibits tricritical behavior. Self-propulsion has a non-perturbative effect on the phase diagram, yielding novel phase behaviors depending on the type of aligning interactions. For aligning interaction that increase monotonically with the density, the tricritical point diverges to infinite density reproducing the standard scenario of a discontinuous flocking transition accompanied by traveling bands. In contrast, for models where the aligning interaction is non-monotonic in density, the system can exhibit either (the nonequilibrium counterpart of) an azeotropic point, associated with a continuous flocking transition, or a state with counterpropagating bands.
A europium-based MOF fluorescent probe for efficiently detecting Co2+ and

CrO

4

2
−
Authors: Luo Jiangnan , Lin Yaqing , Yang Juhao , Xu Cunjin 
Published: May 2024

Abstract
Cobalt is an essential trace element in the human body that is vital for metabolism in living organisms. Insufficient or excessive intake of cobalt can lead to adverse effects. We prepared a europium-based metal–organic framework (Eu-MOF), NH4[Eu(sal)4(phen)2] (abbreviated as Eu-sal, sal = salicylic acid group, phen = 1,10-phenanthroline). Fluorescence investigations revealed that Eu-sal can efficiently and selectively identify Co2+ through a fluorescence quenching effect, with a quenching efficiency K
SV and limit of detection (LOD) of 2.7 × 104 M−1 and 0.37 μM, respectively. In addition, Eu-sal also shows highly selective for

CrO

4

2
−

(K
SV: 3.6 × 104 M−1; LOD: 0.27 μM). The quenching of Eu-sal fluorescence emission by Co2+ and

CrO

4

2
−

ions may be caused by spectral overlap, energy transfer, and competition. Furthermore, Eu-sal has good thermal and chemical stability. These results indicate that Eu-sal is a promising fluorescence probe for highly selective detection of Co2+ and

CrO

4

2
−

ions.
Floating gate potential of gate-all-around floating gate memory cell: parameter extraction and compact model
Authors: Hamzah Afiq , Alias N Ezaila , Johari Zaharah , Tan Michael Loong Peng , Zakaria Jamaluddin 
Published: May 2024

Abstract
The compact modeling of flash memories is crucial for integrated circuit designers to carry out efficient and precise circuit-level evaluations, particularly in the case of 3D NAND flash where the 3D geometry leads to significant parasitic coupling impacts on performance. In this work, we proposed a charge-based modeling approach for gate-all-around floating gate memory cells. The compact model is based on the derived unified charge control model where the mobile charge is explicitly solved. By solving the charge balance model and taking into account voltage-dependent parasitic capacitances for accurate coupling effects, the floating gate potential is accurately computed. The simulation results are validated with numerical TCAD simulation and showed good agreement with TCAD simulation. By solving the charge balance model and considering voltage-dependent parasitic capacitances for more accurate coupling effects, the floating gate potential is accurately calculated. Additionally, the results indicate that subthreshold degradation is caused by interface trap charge in the experimental device, and the proposed model successfully replicates experimental data.
Rectangular extended neck Helmholtz resonant acoustic structure for low frequency broadband sound absorption
Authors: Yan Shanlin , Wu Fei , Zhang Xiao , Zhang Dewen , Wu Zhongyun 
Published: May 2024

Abstract
The Helmholtz resonant structure with rectangular extended neck is designed to solve low-frequency broadband sound absorption problem in this work. Theoretical and finite element absorption models are established and be used for low-frequency acoustic design. What makes it interesting is that all parameters of the rectangular extended neck Helmholtz resonator structure can be adjusted to shift the working frequency. Based on the regularity of the structural parameters, four coupling structures with different neck depths, neck opening areas, cavity cross-sectional areas, and cavity depths are designed respectively, each of which exhibited multiple sound absorption coefficient peaks to enhance the low-frequency absorption capacity of the structure. To further analyze the effectiveness of coupling structure, the broadband acoustic absorption mechanism of the coupled structure is analyzed based on particle vibration velocity distribution. It is found that cells with different acoustic impedance contributed differently to the sound absorption, and cells with longer necks provided better noise reduction for low-frequency. The experiment is verified in the impedance tube, result shows that the coupling structure with 9 cells and a cavity depth of only 4 cm achieved an average sound absorption coefficient of above 0.8 at 210–340 Hz, which verified the accuracy of the theoretical model. Overall, the Helmholtz resonant cavity acoustic structure with rectangular extension neck designed in this work has a simple structure with low-frequency broadband acoustic absorption performance. This provides a new approach for designing low-frequency broadband acoustic structure.
Dy3+ doped KCa(PO3)3 phosphor for white light generation: structural and luminescent studies
Authors: Deepti  , Maurya Sandip , Kumari Sheetal , Rohilla Pooja , Prasad Aman , Rao A S 
Published: May 2024

Abstract
Using the traditional solid-state reaction approach, Dy3+ ions doped KCa(PO3)3 phosphors have been synthesized to investigate their luminescent properties to produce high-quality white light for solid-state lighting applications, particularly in white LEDs. x-ray diffraction (XRD) patterns were used to examine the structure and phase of the phosphors. Using scanning electron microscopy (SEM), the morphology of the as-synthesized phosphor has been investigated. Fourier transform infrared spectroscopy (FT-IR) has been used to investigate several vibrational bands seen in the phosphor. Using diffuse reflectance spectra (DRS), the as-synthesized phosphors’ optical band gap values have been estimated. When Dy3+ ions are excited at 350 nm, the photoluminescence (PL) spectra characteristics observed for the activated KCa(PO3)3 phosphor show strong white area emission due to both 575 nm, which is related to the 4F9/2 → 6H13/2 and 482 nm that is ascribed to 4F9/2
→
6H15/2 transition of Dy3+ ions. Additionally, the concentration quenching of Dy3+ ions doped at 4 mol% is seen in the PL spectra. Based on the observed PL spectra, the computed CIE chromaticity coordinates for the optimised KCa(PO3)3 phosphors are located in the deep white area. The lifespan of the as-titled phosphors decreases as the amount of Dy3+ ions increases in the host lattice. Additionally, the PL decay profiles shows a dual exponential behaviour when excited at 350 nm, with an emission wavelength at 575 nm. The lifetime values were used to calculate the quantum efficiency of the as prepared phosphors. On the basis of the results of the aforementioned studies, we wish to project Dy3+ ion doped KCa(PO3)3 phosphors as white light generating materials in w-LEDs and for other photonic applications.
Bio-ultrasonic synthesis of tin oxide quantum dots: effect of bio-carbon and their UV photocatalytic activity
Authors: Boudjadar Smail , Boumaza Leila , Belamri Zehira 
Published: May 2024

AbstractAn ecofriendly synthesis is realized to elaborate tin oxide quantum dots (SnO2-QDs) using the plant aqueous extract ofAloe Barbadensis Miller(AloeVera) and SnCl4.5H2O at room temperature as a biological solvent and a precursor respectively. The effect of Aloe Vera extract concentration on the properties of SnO2-QDs has been studied. Morphological and structural properties of the as synthesized nanoparticles have been characterized using field effect-scanning electron microscopy (FE-SEM) and x-ray diffraction (XRD). The chemical composition of the nanoparticles was studied by Raman, energy dispersive x-ray (EDX) and Fourier transformation infra-red (FTIR) spectroscopy. The optical properties were investigated by UV–Vis spectrophotometer. The x-ray diffraction analysis showed that all samples have a tetragonal rutile structure, with an estimated crystal size closed to the exciton Bohr radius, indicating a strong confinement of the carriers in the material. The crystallite size of SnO2-QDs nanoparticles decreases as Aloe Vera plant extract concentration increases. The formation of SnO2-QDs and the presence of graphitic carbon in samples were confirmed by Raman spectroscopy, EDX analysis and Fourier transformation infra-red (FTIR) spectroscopy. The blue shift in absorption is the most likely due to the quantum confinement effect. An Ostwald-repining growth model based on the concept of surface energy has been proposed to explain the kinetic growth of SnO2QDs. The photocatalytic activities of the as-prepared powders were confirmed by the fast and efficient degradation of methylene blue (MB).
Information transfer pathways: signal propagation in complex global topologies
Authors: Hu Qitong , Zhang Xiao-Dong 
Published: May 2024

Abstract
In the real world, many dynamic behaviors can be explained by the propagation of perturbations, such as the transfer of chemical signals and the spread of infectious diseases. Previous researchers have achieved excellent results in approximating the global propagation time, revealing the mechanism of signal propagation through multiple paths. However, the known frameworks rely on the extension of physical concepts rather than mathematically rigorous derivations. As a result, they may not perfectly predict time or explain the underlying physical significance in certain specific cases. In this paper, we propose a novel method for decomposing network topology, focusing on two modules: the tree-like module and the path-module. Subsequently, we introduce a new framework for signal propagation analysis, which can be applied to estimate the propagation time for two fundamental global topology modules and provide a rigorous proof for the propagation time in global topology. Compared to previous work, our results are not only more concise, clearly defined, efficient, but also are more powerful in predicting propagation time which outperforms some known results in some cases, for example, biochemical dynamics.Additionally, the proposed framework is based on information transfer pathways, which can be also applied to other physical fields, such as network stability, network controlling and network resilience.
Design of 2.5-D miniaturized frequency selective surface with enhanced oblique stability
Authors: Ul Abidin Zain , Cao Qunsheng , Shah Gulab , Ahmed Afzal 
Published: May 2024

Abstract
This paper presents a miniaturized 2.5-D frequency selective surface (FSS) that exhibits a band stop response at frequency of 1.5 GHz. In the unit cell, the meander patterns on both side of the substrate are connected in series by four vias. Moreover, the meandered pattern in each quadrant is also connected with one of the meander patterns of the adjacent unit cell. In this manner, a 2.5-D closed loop is created with large perimeter. The enlarged perimeter amplifies the effective inductance and leads to a decrease in both the resonant frequency and the dimensions of unit cell. Subsequently, the proposed FSS demonstrates excellent miniaturization with an overall size of 0.038 λ
0 × 0.038 λ
0. Moreover, the frequency response is highly stable up to 86° for both TE and TM polarization. The resonance mechanism of the designed FSS is explicated through distribution of surface current and electric field. The testing board of the proposed FSS has been fabricated for the verification of the design. The measured frequency response of the prototype are congruent with the simulation results. The distinguished features of the constructed structure are enhanced angular stability, miniaturized unit cell, low profile, simple geometry and easy fabrication.
The organic HTL in highly efficient germanium-alloyed CsSnI3 perovskite solar cell: a modelling and computational analysis
Authors: Ranjan Rahutosh , Verma Sona , Tripathi Naveen Mani 
Published: May 2024

Abstract
It is usually anticipated that perovskites will be an appealing material for extremely effective solar cells. However, its practical applications are constrained by its hazardous properties and stability. Thus, CsSn0.5Ge0.5I3, a more environmentally benign substitute for toxic lead-based perovskites, provides superior stability in solar cells. This work reports on the numerical modeling and computational analysis of a heterostructure CsSn0.5Ge0.5I3, with TiO2 and D-PBTTT-14 serving as the electron and hole transport layers, respectively. The introduction of D-PBTTT-14 as a hole transport layer was motivated by its superior stability over existing organic HTLs. Furthermore, the higher electron–hole pair generation rate and very favorable absorption coefficients of each layers manifested improved efficiency. Various parameters were examined to enhance the newly designed solar cell performance such as: thickness, defect density, doping density, coefficient of radiative recombination, defect at interface, shunt and series resistance, front and back contacts, and operating temperature. Perovskite solar cells with their current architecture have the potential to achieve a current density (Jsc) of 28.31 mA cm−2, an open-circuit voltage (Voc) of 1.24 V, a fill factor (FF) of 85.90%, and efficiency of 30.27%.
Further study on the Rulkov neuron: geometric control, circuit realization and chaos-based encryption
Authors: Xia Ming , Li Chunbiao , Li Yongxin , Li Peiran , khan Awais 
Published: May 2024

Abstract
Rulkov neuron with various firing modes is exhaustively explored by numerical simulation aiming to disclose its unique properties of evolution. Transient chaos and the coexistence of periodic state and chaos are found. Furthermore, it is found that the chaotic attractors in the neuron can also be arranged flexibly in phase space by a single offset booster, while the amplitude of firings is rescaled by an independent amplitude controller. Circuit implementation based on MCU is carried out demonstrating the predicted dynamics. Confidentiality and security of data play an important role in safeguarding national production and livelihood. In this paper, the chaotic firing is introduced into the Tiny Encryption Algorithm (TEA) for image encryption based on MCU combined with metrics analysis. It is proven that the Chaos-based Tiny Encryption Algorithm (ChaosTEA) exhibits higher efficiency and security compared to the traditional TEA algorithm.
Fast rotation of nuclei with extreme isospin in the vicinity of neutron and proton drip lines
Authors: Afanasjev A V , Teeti S , Taninah A 
Published: May 2024

Abstract
The analysis of the present understanding of collective rotation in very neutron-rich nuclei is presented. It is shown that collective rotation can lead to the increase of stability of rotational states with increasing spin. The detailed investigation of rotational excitations in very proton-rich nuclei confirms this conclusion and indicates that experimental studies of such features are more feasible in the nuclei near proton drip line. They also show that rotational bands which are proton quasi-bound at zero or low spins can be transformed into proton bound ones at high spin by collective rotation of nuclear systems. This is due to strong Coriolis interaction which acts on high-j or strongly mixed M orbitals and drives the highest in energy occupied single-particle states into negative energy domain. These physical mechanisms lead to a substantial extension of the nuclear landscape beyond the spin zero proton drip line. In addition, a new phenomenon of the formation of giant proton halos in rotating nuclei emerges: it is triggered by the occupation of strongly mixed M intruder orbitals.
Simulating the epoch of helium reionization in photon-conserving semi-numerical code SCRIPT
Authors: Kapahtia Akanksha , Roy Choudhury T. 
Published: May 2024

Abstract
The reionization of the second electron of helium (HeII) leaves important imprints on the thermal and ionization state of the intergalactic medium (IGM). Observational evidence suggests that HeII reionization ended at z ≃ 3 due to ionizing photons emitted predominantly by quasars. We present efficient semi-numerical simulations of helium reionization in a 230 h-1 Mpc box, that takes into account the spatial patchiness of reionization coupled with photoheating of the IGM. Dark matter haloes are assigned quasars using empirical measurements of the quasar luminosity function, assuming a universal quasar lifetime consistent with duty cycle values inferred from measurements of the quasar clustering. The ionizing photon field from quasars is then included in the semi-numerical Code for ReionIzation with PhoTon conservation (SCRIPT), which was originally developed for modeling hydrogen reionization. In this work, we make appropriate modifications to SCRIPT for modeling inhomogenous HeII reionization and the corresponding thermal history of the IGM is modelled via a subgrid prescription. Our model has three main free parameters i.e. the global clumping factor 𝒞HeIII, the temperature increase due to photoheating T
re
He and the quasar spectral energy distribution (SED) index, α
UV. Our fiducial model with 𝒞HeIII = 15.6 and T
re
He ∼ 6000 K gives reasonable values for the empirical measurements of the temperature density equation of state at these redshifts, assuming that quasars brighter than M1450 < -21 and having α
UV = 1.7 contribute to HeII reionization. The efficiency of our code shows promising prospects for performing parameter estimation in future, for models of HeII reionization using observations of the Lyα forest.
Constraining multi-field inflation using the SPHEREx all-sky survey power spectra
Authors: Shiveshwarkar Charuhas , Brinckmann Thejs , Loverde Marilena 
Published: May 2024

Abstract
We investigate how well the SPHEREx all-sky survey can constrain local primordial non-Gaussianity beyond the parameter f
NL using galaxy power spectra. We forecast joint constraints on the parameters f
NL, g
NL and τ
NL obtained assuming a simple two-field curvaton model of inflation. The parameters f
NL and g
NL characterise the squeezed limits of the primordial bispectrum and trispectrum respectively, and lead to a characteristic scale-dependence of the galaxy bias that increases out to arbitrarily large scales. Values of the parameter τ
NL > (6/5f
NL)2 cause the galaxy power spectrum to have a stochastic component which also increases out to arbitrarily large scales. Our MCMC forecasts indicate that SPHEREx can provide joint constraints on any two of the three parameters f
NL, g
NL and τ
NL. Due to strong degeneracies among these parameters, measurements of the galaxy power spectra alone may not be sufficient to jointly constrain all three. Constraints on f
NL, g
NL and τ
NL obtained from galaxy power spectrum observations depend on the modelling of underlying nuisance parameters. We study the robustness of our forecast constraints to modelling choices and note that even with relatively conservative modelling assumptions, SPHEREx galaxy power spectra can provide strong evidence of local non-Gaussianity, even if the particular values of f
NL and g
NL cannot be measured precisely.
Half-integer Shapiro steps in MgB2 focused He ion beam Josephson junctions
Authors: Yin 殷 Dali 大利 , Cai 蔡 Xinwei 欣炜 , Xu 徐 Tiequan 铁权 , Sun 孙 Ruining 瑞宁 , Han 韩 Ying 颖 , Zhang 张 Yan 焱 , Wang 王 Yue 越 , Gan 甘 Zizhao 子钊 
Published: May 2024

Abstract
Half-integer microwave induced steps (Shapiro steps) have been observed in many different Josephson junction systems, which have attracted a lot of attention because they signify the deviation of current phase relation (CPR) and uncover many unconventional physical properties. In this article, we first report the discovery of half-integer Shapiro steps in MgB2 focused He ion beam (He-FIB) Josephson junctions. The half-integer steps’ dependence on microwave frequency, temperature, microwave power, and magnetic field is also analyzed. We find that the existence of half-integer steps can be controlled by the magnetic field periodically, which is similar to that of high temperature superconductor (HTS) grain boundary junctions, and the similarity of the microstructures between gain boundary junctions and He-FIB junctions is discussed. As a consequence, we mainly attribute the physical origin of half-integer steps in MgB2 He-FIB junctions to the model that a He-FIB junction is analogous to a parallel junctions’ array. Our results show that He-FIB technology is a promising platform for researching CPR in junctions made of different superconductors.
Observation of parabolic electron bands on superconductor LaRu2As2
Authors: Zhou 周 Xingtai 兴泰 , Li 李 Geng 更 , Pan 潘 Lulu 禄禄 , Chen 陈 Zichao 子超 , Li 李 Meng 萌 , Shi 时 Yanhao 延昊 , Yang 杨 Haitao 海涛 , Gao 高 Hong-Jun 鸿钧 
Published: May 2024

Abstract
Ru-based superconductor LaRu2As2 has been discovered exhibiting the highest critical temperature of ∼ 7.8 K among iron-free transition metal pnictides with the ThCr2Si2-type crystal structure. However, microscopic research on this novel superconducting material is still lacking. Here, we utilize scanning tunneling microscopy/spectroscopy to uncover the superconductivity and surface structure of LaRu2As2. Two distinct terminating surfaces are identified on the cleaved crystals, namely, the As surface and the La surface. Atomic missing line defects are observed on the La surface. Both surfaces exhibit a superconducting gap of ∼ 1.0 meV. By employing quasiparticle interference techniques, we observe standing wave patterns near the line defects on the La atomic plane. These patterns are attributed to quasiparticle scattering from two electron type parabolic bands.