bluuebunny/crossref_metadata_2025 huggingface dataset:
Visible-light responsive CdS-QDs modified InGaZnO synapse for biologically plausible color-to-gray conversion
Authors: Zhu Li , Li Sixian , Shu Kaiyi , Ke Shuo , Wan Xiang , Sun Huabin , Yan Shancheng , Xu Yong , Tan Chee Leong , He Gang , Yu Zhihao , Wan Changjin
Published: July 2024

The energy-efficient perceptual capabilities of the human visual system have inspired the development of optoelectronic neuromorphic devices to replicate the essential properties. Color vision that is highly important for perception and cognitive behaviors, such as object recognition, esthetics, and communication, has recently been reported based on optoelectronic neuromorphic devices. The responses to different wavelengths of light are mainly dependent on power density, whereas the eye recognizes color images based on luminosity. This Letter presents a quantum dots (QDs) modified InGaZnO (IGZO) synaptic transistor based on an IGZO/CdS-QDs/PMMA heterojunction. These IGZO-based synapses show significant responsivity to 655-nm light through the spectrum broadening by QDs. More importantly, luminance-based color-to-gray conversion can be realized with this device using a spike encoding scheme, transforming color images into grayscale in parallel. Notably, the QDs modified IGZO-based synapses demonstrated a remarkable 34.3% improvement in recognition accuracy on the multicolor MNIST dataset in comparison with the pristine devices. Our results indicate that this visible-light responsive IGZO-based synapse has great potential for endowing the neuromorphic visual system with enhanced color vision and provides a biologically plausible approach for color-to-gray conversion.
Stochastically accelerated perturbative triples correction in coupled cluster calculations
Authors: Damour Yann , Gallo Alejandro , Scemama Anthony
Published: July 2024

We introduce a novel algorithm that leverages stochastic sampling techniques to compute the perturbative triples correction in the coupled-cluster framework. By combining elements of randomness and determinism, our algorithm achieves a favorable balance between accuracy and computational cost. The main advantage of this algorithm is that it allows for the calculation to be stopped at any time, providing an unbiased estimate, with a statistical error that goes to zero as the exact calculation is approached. We provide evidence that our semi-stochastic algorithm achieves substantial computational savings compared to traditional deterministic methods. Specifically, we demonstrate that a precision of 0.5 millihartree can be attained with only 10% of the computational effort required by the full calculation. This work opens up new avenues for efficient and accurate computations, enabling investigations of complex molecular systems that were previously computationally prohibitive.
Leveraging existing data to improve antimicrobial resistance-related mortality estimates for Australia
Authors: Wozniak Teresa M. , Nguyen Anthony , Good Norm , Coombs Geoffrey W.
Published: July 2024

Antimicrobial resistance (AMR) is a global pandemic, however, estimating its burden is a complex process. As a result, many countries rely on global estimates to infer burden within their own setting. With a growing number of recent publications quantifying AMR burden in Australia, and an expansion of surveillance programs, enumerating AMR mortality for Australia is feasible. We aimed to leverage existing published data to assess methodological factors contributing to the considerable variation in AMR-related mortality and provide two reliable estimates of AMR mortality in Australia. This is a necessary step towards generating meaningful measures of AMR burden in Australia.
Enhancement of the anomalous Hall effect by distorting the Kagome lattice in an antiferromagnetic material
Authors: Roychowdhury Subhajit , Samanta Kartik , Singh Sukriti , Schnelle Walter , Zhang Yang , Noky Jonathan , Vergniory Maia G. , Shekhar Chandra , Felser Claudia
Published: July 2024

In topological magnetic materials, the topology of the electronic wave function is strongly coupled to the structure of the magnetic order. In general, ferromagnetic Weyl semimetals generate a strong anomalous Hall conductivity (AHC) due to a large Berry curvature that scales with their magnetization. In contrast, a comparatively small AHC is observed in noncollinear antiferromagnets. We investigated HoAgGe, an antiferromagnetic (AFM) Kagome spin-ice compound, which crystallizes in a hexagonal ZrNiAl-type structure in which Ho atoms are arranged in a distorted Kagome lattice, forming an intermetallic Kagome spin-ice state in the
ab
-plane. It exhibits a large topological Hall resistivity of ~1.6 µΩ-cm at 2.0 K in a field of ~3 T owing to the noncoplanar structure. Interestingly, a total AHC of 2,800 Ω
−1
cm
−1
is observed at ~45 K, i.e., 4
T
N
, which is quite unusual and goes beyond the normal expectation considering HoAgGe as an AFM Kagome spin-ice compound with a
T
N
of ~11 K. We demonstrate further that the AHC below
T
N
results from the nonvanishing Berry curvature generated by the formation of Weyl points under the influence of the external magnetic field, while the skew scattering led by Kagome spins dominates above the
T
N
. These results offer a unique opportunity to study frustration in AFM Kagome lattice compounds.
WITHDRAWN: Crossover from relativistic to non-relativistic net magnetization for MnTe altermagnet candidate
Authors: Orlova N. N. , Avakyants A. A. , Timonina A. V. , Kolesnikov N. N. , Deviatov E. V.
Published: July 2024

Notice of Withdrawal

This paper was withdrawn by IOP Publishing on 30/08/2024. This paper was published due to an error. The authors are free to publish this work elsewhere. IOP Publishing apologise for this error.
Strong Cosmic Censorship with bounded curvature
Authors: Reintjes Moritz
Published: July 2024

In this paper we propose a weaker version of Penrose’s much heeded Strong Cosmic Censorship (SCC) conjecture, asserting inextendability of maximal Cauchy developments by manifolds with Lipschitz continuous Lorentzian metrics and Riemann curvature bounded in Lp
. Lipschitz continuity is the threshold regularity for causal structures, while curvature bounds rule out infinite tidal accelerations, arguing for physical significance of this weaker SCC conjecture. The main result of this paper, under the assumption that no extensions exist with higher connection regularity

W
loc

1
,
p

, proves in the affirmative this SCC conjecture with bounded curvature for p sufficiently large, (p > 4 to address uniform bounds, p > 2 without uniform bounds).
Role of complexity on the minimal deformation of black holes
Authors: Yousaf Z , Bamba Kazuharu , Almutairi Bander , Khan S , Bhatti M Z
Published: July 2024

We investigate spherically symmetric classes of anisotropic solutions within the realm of a schematic gravitational decoupling scheme, primarily decoupling through minimal geometric deformation, applied to non-rotating, ultra-compact, self-gravitational fluid distributions. In this respect, we employ the minimal complexity factor scheme to generate physically realistic models for anisotropic matter distributions, using a well-behaved model. The zero-complexity factor condition enables us to determine the deformation function for solving the decoupled system. We explore all the structure-defining scalar variables, such as density inhomogeneity, strong energy condition, density homogeneity, and the complexity factor (an alloy of density inhomogeneity and pressure anisotropy) for the decoupling constant ranging between 0 and 1. We observe that the anisotropy vanishes when the coupling constant is set to unity. This finding holds significance as it implies that, in the context of a zero-complexity factor approach, an anisotropic matter distribution becomes perfect without requiring any isotropy requirements. This work effectively explored the impact of complexity on the composition of self-gravitational stellar distributions. This effective approach enables the development of new, physically realistic isotropic stellar models for anisotropic matter distributions. Additionally, our findings indicate that the complexity factor in static, spherically symmetric self-gravitational objects can significantly affect the nature of the matter distribution within these systems. It is concluded that the minimally deformed Durgapal-IV model features an increasing pressure profile, and the local anisotropy of pressure vanishes throughout the model under complexity-free conditions.
Imprints of the operator ordering ambiguity on the dynamics of perfect fluid dominated quantum Universe
Authors: Sahota Harkirat Singh
Published: July 2024

Sharply peaked quantum states are conjectured to be conducive to the notion of a quantum-corrected spacetime. We investigate this conjecture for a flat-FLRW model with perfect fluid, where a generalized ordering scheme is considered for the gravitational Hamiltonian. We study the implications of different ordering choices on the dynamics of the quantum Universe. We demonstrate that the imprints of the operator ordering ambiguity are minimal, and quantum fluctuations are small in the case of sharply peaked states, leading to a consistent notion of a quantum-corrected spacetime defined via the expectation value of the scale factor. Surprisingly, the ordering imprints survive far away from the singularity through the quantum fluctuations in the quantum-corrected spacetime for broadly peaked states.
Doppler sensitivity and resonant tuning of Rydberg atom-based antennas
Authors: Weichman Peter B
Published: July 2024

Radio frequency antennas based on Rydberg atom vapor cells can in principle reach sensitivities beyond those of any conventional wire antenna, especially at lower frequencies where very long wires are needed to accommodate the increasing wavelength. They also have other desirable features such as consisting of nonmetallic, hence lower profile, elements. This paper presents a detailed theoretical investigation of Rydberg antenna sensitivity, elucidating parameter regimes that could cumulatively lead to a sensitivity increase 2–3 orders of magnitude beyond that of currently tested configurations. The key insight is to optimally combine the advantages of two well-studied approaches: (i) three laser ‘2D star configuration’ setups that, when enhanced with increased laser power, to some degree compensate for atom motion-induced Doppler broadening, and (ii) resonant coupling between a pair of near-degenerate Rydberg levels, tuned via a local oscillator to the incident signal of interest. The advantage of the star setup is subtle because it only restores the overall sensitivity to the expected Doppler-limited value, compensating for additional significant off-resonance reductions where differently moving atom sub-populations destructively interfere with each other in the net signal. An additional unique advantage of local oscillator tuning is that it leads to vastly narrower line widths, as low as ∼10 kHz set by the intrinsic Rydberg state lifetimes, rather than the typical ∼10 MHz scale set by the core state lifetimes. Intuitively, with this setup the two Rydberg states may be tuned to act as an independent high-q cavity, a point of view supported by a study of the frequency-dependence of the antenna resonant response. There are a number of practical experimental advances, especially larger ∼1 cm laser beam widths, required to suppress various extrinsic line broadening effects and to fully exploit this ‘Rydberg superheterodyne’ response.
Field management in NiO
x
/β-Ga2O3 merged-PIN Schottky diodes: simulation studies and experimental validation
Authors: Vasquez Jose Manuel Taboada , Mukherjee Ankita , Singh Smriti , Khandelwal Vishal , Yuvaraja Saravanan , Maciel Garcia Glen Isaac , Rajbhar Manoj , Li Xiaohang , Sarkar Biplab
Published: July 2024

In recent years, p-type NiO
x
has emerged as a promising alternative to realize kilovolt-class β-Ga2O3-based PN junction diodes. However, only a handful of studies could realize β–Ga2O3-based unipolar diodes using NiO
x
as a guard ring or floating rings. In this work, we investigate the device design of NiO
x
/β-Ga2O3 unipolar diodes using the technology computer aided design simulations and experimental validations. We show that a systematic electric field management approach can potentially lead to NiO
x
/β-Ga2O3 heterojunction unipolar diode and offer enhanced breakdown characteristics without a severe compromise in the ON-state resistance. Accordingly, the NiO
x
/β-Ga2O3 heterojunction diode in the merged-PIN Schottky configuration is shown to outperform the regular Schottky diode or junction barrier Schottky diode counterpart. The analysis performed in this work is believed to be valuable in the device design of β-Ga2O3-based unipolar diodes that use a different p-type semiconductor candidate as guard rings and floating rings.
Saturable absorption properties of mixed lead-tin halide perovskites and their application in near-infrared ultrafast lasers
Authors: Lan Xinru , Yang Cheng , Wei Chengming , Liu Jiabao , Zhang Zeyu , Chen Zhengwei , Wang Xu , Hu Ziyang
Published: July 2024

Mixed lead–tin halide perovskites, as highly sensitive materials in the near-infrared region, hold significant potential for optoelectronic device applications. Here, mixed lead–tin halide perovskite saturable absorbers (SAs) have been developed by coupling with the side-polished surfaces of the single-mode fibers and excellent saturable absorption effects of the mixed lead–tin halide perovskite SAs have been demonstrated in the near-infrared region. By constructing the in-gap site assisted carrier transfer mode, the saturation absorption process of the mixed lead–tin halide perovskite SAs can be well explained, in which defects as in-gap sites can help the photon-generated carriers transfer into the conduction band and promote the Pauli-blocking-induced absorption bleaching in the SA. Moreover, ytterbium-doped fiber lasers based on perovskite SAs have been fabricated, and mode-locked operations at 1040 nm are achieved using the mixed lead–tin halide perovskite SA, generating ultra-short pulses with a pulse width of 683 fs, 3 dB bandwidth of 4.88 nm, signal-to-noise ratio exceeding 49.74 dB, and a repetition rate of 3.74 MHz. Our findings demonstrate that the mixed lead–tin halide perovskite SAs have excellent optical modulation capability and promising applications in the field of ultrafast photonics.
Enhanced flexoelectricity of liquid with hydrated ions
Authors: Li Yifan , Li Yanyu , Feng Xingjian , Zhai Chongpu , Zhang Shuwen , Xu Minglong
Published: July 2024

Flexoelectricity, denoted as an electromechanical coupling effect from strain gradient introduced polarization, is prevalent in dielectric materials. However, its application in low-viscosity liquids has been limited by the scale of the flexoelectric coefficient. This study explores the flexoelectric coefficient of various hydrated ion solutions through a series of experiments. Additionally, the interplay between ion adsorption and the flexoelectric effect is investigated by using interfacial voltage detection. By introducing hydrated structures into liquids, a significant enlargement of the flexoelectric coefficient up to 2.3 × 10−9 C m−1 is obtained in Fe2(SO4)3 solution by four times than DI water. These findings highlight the remarkable electromechanical properties of liquid materials with hydrated ions and suggest promising avenues for the application of liquid dielectrics in hydrovoltaic technology, ionotronic devices, and energy harvesters.
Extended Fayans energy density functional: optimization and analysis
Authors: Reinhard Paul-Gerhard , O’Neal Jared , Wild Stefan M , Nazarewicz Witold
Published: July 2024

The Fayans energy density functional (EDF) has been very successful in describing global nuclear properties (binding energies, charge radii, and especially differences of radii) within nuclear density functional theory. In a recent study, supervised machine learning methods were used to calibrate the Fayans EDF. Building on this experience, in this work we explore the effect of adding isovector pairing terms, which are responsible for different proton and neutron pairing fields, by comparing a 13D model without the isovector pairing term against the extended 14D model. At the heart of the calibration is a carefully selected heterogeneous dataset of experimental observables representing ground-state properties of spherical even–even nuclei. To quantify the impact of the calibration dataset on model parameters and the importance of the new terms, we carry out advanced sensitivity and correlation analysis on both models. The extension to 14D improves the overall quality of the model by about 30%. The enhanced degrees of freedom of the 14D model reduce correlations between model parameters and enhance sensitivity.
First-principles calculation of Hubbard U for Terbium metal under high pressure
Authors: Burnett Logan A , Clay Matthew P , Vohra Yogesh K , Chen Cheng-Chien
Published: July 2024

Using density functional theory (DFT) and linear response approaches, we compute the on-site Hubbard interaction U of elemental Terbium (Tb) metal in the pressure range ∼ 0–65 GPa. The resulting first-principles U values with experimental crystal structures enable us to examine the magnetic properties of Tb using a DFT+U method. The lowest-energy magnetic states in our calculations for different high-pressure Tb phases—including hcp, α-Sm, and dhcp—are found to be compatible with the corresponding magnetic ordering vectors reported in experiments. The result shows that the inclusion of Hubbard U substantially improves the accuracy and efficiency in modeling correlated rare-earth materials. Our study also provides the necessary U information for other quantum many-body techniques to study Tb under extreme pressure conditions.
Enhanced feature extraction YOLO industrial small object detection algorithm based on receptive-field attention and multi-scale features
Authors: Tao Hongfeng , Zheng Yuechang , Wang Yue , Qiu Jier , Stojanovic Vladimir
Published: July 2024

To guarantee the stability and safety of industrial production, it is necessary to regulate the behavior of employees. However, the high background complexity, low pixel count, occlusion and fuzzy appearance can result in a high leakage rate and poor detection accuracy of small objects. Considering the above problems, this paper proposes the Enhanced feature extraction-You Only Look Once (EFE-YOLO) algorithm to improve the detection of industrial small objects. To enhance the detection of fuzzy and occluded objects, the PixelShuffle and Receptive-Field Attention (PSRFA) upsampling module is designed to preserve and reconstruct more detailed information and extract the receptive-field attention weights. Furthermore, the multi-scale and efficient (MSE) downsampling module is designed to merge global and local semantic features to alleviate the problem of false and missed detection. Subsequently, the Adaptive Feature Adjustment and Fusion (AFAF) module is designed to highlight the important features and suppress background information that is not beneficial for detection. Finally, the EIoU loss function is used to improve the convergence speed and localization accuracy. All experiments are conducted on homemade dataset. The improved YOLOv5 algorithm proposed in this paper improves mAP@0.50 (mean average precision at a threshold of 0.50) by 2.8% compared to the YOLOv5 algorithm. The average precision and recall of small objects show an improvement of 8.1% and 7.5%, respectively. The detection performance is still leading in comparison with other advanced algorithms.
Equivalent circuit fitting method for microwave characterisation of low-k dielectric thin films
Authors: Guerenneur A , Kouznetsov D , Narducci D , Luciano F , Sun X , Van Dorpe P , Ciubotaru F , Adelmann C
Published: July 2024

A new equivalent circuit fitting analysis scheme is proposed to analyse the measured data of test structures originally developed to characterise high-κ dielectrics at frequencies up to 5 GHz (Zhengxiang et al 1998 IEEE Trans. Electron Devices
45 1811–6). It is compared to an extension of the analysis which can be used for high-κ dielectrics at up to 50 GHz (Rundqvist et al 2004 Integr. Ferroelectr.
60 1–19). The proposed scheme focuses on the accurate characterisation of low-κ dielectrics, which exhibit greater sensitivity to various parasitics. The scheme utilises the same concentric capacitor devices and measurement setup as the original method, maintaining the advantage of ease in fabrication of the original approach. The physical model employed in the analysis step of the original method, which tended to overestimate the dielectric permittivity, has been enhanced by incorporating fringing fields and a parasitic gap capacitance as circuit elements. The accuracy of the new approach is validated using experimental data, demonstrating its ability to more accurately determine the dielectric permittivity compared to the original method.
Rare earth oxide Y2O3 modified g-C3N4 for efficient photocatalytic hydrogen production: photocatalytic performance and electron transfer channels
Authors: Niu Fengyan , Zhang Ziyang , Lei Weiyan , Li Jiashuang , Wang Baoxiang , Shen Yi
Published: July 2024

This work used a one-step calcination process to prepare g-C3N4 composites with varying Y2O3 loading. XRD, TEM, and XPS verified the structure and morphology of the composite photocatalyst, and its photoelectrochemical and hydrogen production performance were studied. According to the experimental results, it is found that the composite structure between Y2O3 and g-C3N4 effectively suppresses the photoelectron–hole complex and enhances the photocatalytic hydrogen production properties of g-C3N4. Under the irradiation of a 300 W xenon lamp, YCN-3 had superior photocatalytic hydrogen generation performance, achieving a rate of 1079.61 μmol g−1 h−1, which was 2.3 times greater than that of g-C3N4 in its unmodified state. After three consecutive photocatalytic operations, satisfactory stability and reusability were obtained. Finally, the possibility of a mechanism for the photocatalytic charge transfer pathway is discussed, which provides an effective way for g-C3N4 photocatalytic hydrogen production.
Thermal-electrical analogy for simulations of superconducting power cables
Authors: de Sousa Wescley T B , Kottonau Dustin , Murta-Pina João , Morandi Antonio , Noe Mathias
Published: July 2024

Due the integration of superconducting technologies into electrical networks around the world, its precise simulations in power grids are increasingly becoming a desirable outcome. Over the years, sophisticated methods have been used to model superconducting power cables and, in this way, predict its behavior under different conditions. Most of the available models, however, are not advisable to be used and embedded in power system simulators. In this manuscript, we focus on the development of a method specifically for modeling superconducting cables in traditional power grid simulators. We start developing the model through a case example, within the basic concepts are introduced and later expanded to general cases. The model also incorporates the transient behavior of the cooling media, which is mandatory for such cables. It has been observed that the proposed model requires less computational effort and is able to deliver accurate results when compared to more advanced methods.
Topological insulator based axial superconducting quantum interferometer structures
Authors: Zimmermann Erik , Rehman Jalil Abdur , Schleenvoigt Michael , Karthein Jan , Frohn Benedikt , Behner Gerrit , Lentz Florian , Trellenkamp Stefan , Neumann Elmar , Schüffelgen Peter , Lüth Hans , Grützmacher Detlev , Schäpers Thomas
Published: July 2024

Nanoscale superconducting quantum interference devices are fabricated in-situ from a single Bi0.26Sb1.74Te3 nanoribbon that is defined using selective-area growth and contacted with superconducting Nb electrodes via a shadow mask technique. We present

h

/

(
2
e
)

magnetic flux periodic interference in both, fully and non-fully proximitized nanoribbons. The pronounced oscillations are attributed to interference effects of coherent transport through the topological surface states encompassing the cross-section of the nanoribbon.
The A-15-type superconducting hydride La4H23: a nanograined structure with low strain, strong electron-phonon interaction, and a moderate level of nonadiabaticity
Authors: Talantsev Evgeny F , Chistyakov Vasiliy V
Published: July 2024

For seven decades, when referring to A-15 superconductors, we meant metallic A3B alloys (where A is a transition metal, and B is group IIIB and IVB elements) discovered by Hardy and Hulm (1953 Phys. Rev.
89 884). Nb3Ge exhibited the highest superconducting transition temperature, Tc
= 23K, among these alloys. One of these alloys, Nb3Sn, is the primary material in modern applied superconductivity. Recently, Guo et al (2024 Natl Sci. Rev. nwae149, https://doi.org/10.1093/nsr/nwae149) extended the family of superconductors where the metallic ions are arranged in the beta tungsten (A-15) sublattice by observation of Tc

,zero = 81K in the La4H23 phase compressed at P = 118 GPa. Despite the fact that La4H23 has much lower Tc
in comparison with the near-room-temperature superconducting LaH10 phase (Tc

,zero = 250K at P ∼ 200 GPa) discovered by Drozdov et al (2019 Nature
569 531), La4H23 holds the record for the highest Tc
within the A-15 family. Cross et al (2024 Phys. Rev. B 109 L020503) confirmed the high-temperature superconductivity in compressed La4H23. In this paper, we analyzed available experimental data measured in La4H23 and found that this superconductor exhibits a nanograined structure, 5.5 nm ⩽ D ⩽ 35 nm, low crystalline strain,

|

ε

|

⩽ 0.003, strong electron–phonon interaction, 1.5 ⩽ λe-ph⩽ 2.55, and a moderate level of nonadiabaticity, 0.18 ⩽ Θ
D
/T
F ⩽ 0.22 (where Θ
D
is the Debye temperature, and T
F is the Fermi temperature). We found that the derived Θ
D
/T
F and Tc
/T
F values for the La4H23 phase are similar to those in MgB2, cuprates, pnictides, and the near-room-temperature superconductors H3S and LaH10.

To the memory of Martin J. Ryan, man and scientist who taught EFT the intricacies of X-ray diffraction.
Laser powered dissipative quantum batteries in atom-cavity QED
Authors: Beleño Zamir , Santos Marcelo F , Barra Felipe
Published: July 2024

The interaction of a three-level atom with the electromagnetic field of a quantum cavity in the presence of a laser field presents a rich behavior in the dispersive regime that we exploit to discuss two quantum batteries. In the first setup, we consider a single three-level atom interacting sequentially with many cavities, each in a thermal state. We show that under this process, the atom converges towards an equilibrium state that displays population inversion. In the second setup, a stream of atoms in a thermal state interacts sequentially with a single cavity initially in a thermal state at the same temperature as the atoms. We show that the cavity’s energy increases continuously as the stream of atoms continues to cross, and the cavity does not reach an equilibrium state. After many atoms have traveled, the cavity’s state becomes active, storing extractable energy that increases in proportion to the work done by the laser. However, the same dynamics may involve only two cavity levels in an interesting limit called the highly selective regime. In that regime, the cavity reaches an equilibrium state similar to the one of the atom in the first scenario. The charging process we propose is robust. We discuss its thermodynamics and evaluate the energy supplied by the laser, the energy stored in the battery, and, thus, the device’s efficiency. We also analyze the role of damping.
Exact moments for trapped active particles: inertial impact on steady-state properties and re-entrance
Authors: Patel Manish , Chaudhuri Debasish
Published: July 2024

In this study, we investigate the behavior of inertial active Brownian particles in a d-dimensional harmonic trap in the presence of translational diffusion. While the solution of the Fokker–Planck equation is generally challenging, it can be utilized to compute the exact time evolution of all time-dependent dynamical moments using a Laplace transform approach. We present the explicit form for several moments of position and velocity in d-dimensions. An interplay of time scales assures that the effective diffusivity and steady-state kinetic temperature depend on both inertia and trap strength, unlike passive systems. The distance from equilibrium, measured by the violation of equilibrium fluctuation-dissipation and the amount of entropy production, decreases with increasing inertia and trap strength. We present detailed ‘phase diagrams’ using kurtosis of velocity and position, showing possibilities of re-entrance to equilibrium.
Exploring the dynamic interplay of intermodal and higher order dispersion in nonlinear negative index metamaterials
Authors: Veni S Saravana , Mani Rajan M S , Biswas Anjan , Alshomrani Ali Saleh
Published: July 2024

Our study delves into the intricate interplay of various factors within metamaterials, with a focus on modulation instability. Through our research, we elucidate the intricate dynamics involving intermodal dispersion, self-steepening effect, higher order dispersion, and plane wave amplitude, showcasing their competition and influence on modulation instability phenomena. We aim to explore the impact of intermodal dispersion and higher-order effects by numerically solving the generalized nonlinear Schrödinger equation (NLSE), which models the propagation of a few-cycle pulse in a nonlinear metamaterial. Our modulation instability (MI) analysis captures the complex dynamics these factors introduce. We demonstrate the spatiotemporal evolution of MI under different parameter values, revealing how these variations influence the instability’s development and characteristics. This approach provides a detailed understanding of the system’s behavior across various conditions, highlighting the roles of intermodal dispersion and higher-order effects. We demonstrate that the behavior of modulation instability bands and their reliance on parameters such as self-steepening and wave amplitude is contingent upon the specific characteristics of the optical setup and medium dispersion properties
A highly effective PANI@(Ce-Er) dual doped ZnO (PCEZ) nanocomposite as UV-light driven photocatalyst for degradation of MB dye: synthesis and characterization
Authors: Dhanda Ekta , Nain Aditi , Dahiya Sanjay
Published: July 2024

Utilizing ecologically friendly methods to address wastewater concerns is paramount. In this study, we developed novel PANI@(Ce-Er) dual-doped ZnO (PCEZ) nanocomposites using a wet impregnation approach assisted by ultrasound. These composites were thoroughly characterized using XRD, FESEM, EDX, UV-DRS, PL, and Impedance Analyzer techniques to assess their structural, optical, and electrical properties. Structural characterization was conducted to analyze the crystalline behavior and chemical composition of the synthesized samples. UV-DRS and PL spectroscopy were utilized to analyze their optical properties. Compared to PANI alone, the PCEZ heterojunction demonstrated enhanced photocatalytic stability and efficiency. Notably, in neutral media, the PCEZ heterojunction exhibited a significant photodegradation efficiency against methylene blue (MB), achieving approximately to 90.13% degradation. Morphology analysis of the synthesized samples and elemental composition was effectively performed using SEM images and EDX data. The UV-DRS investigation aimed to confirm the active contacts of dopant metals with polyaniline backbone chains and assess the energy band gap, which defines the absorption behavior of the photocatalyst. Kinetic studies of methylene blue degradation were characterized using the Pseudo First-Order relation, with the best adjusted R2 value of 0.9947 observed for 50% w/w (PANI@(Ce-Er)-ZnO). The produced PANI@(Ce-Er) dual-doped ZnO nanocomposites show promise as effective photocatalyst for the elimination of methylene blue in aqueous environments.
Floquet geometric entangling gates in ground-state manifolds of Rydberg atoms
Authors: Sun Hao-Wen , Wu Jin-Lei , Su Shi-Lei
Published: July 2024

We propose new applications of Floquet theory in Rydberg atoms for constructing quantum entangling gates in atomic ground-state manifolds. By dynamically periodically modulating the Rabi frequencies of transitions between ground and Rydberg states of atoms, error-resilient two-qubit entangling gates can be implemented in the regime of Rydberg blockade. According to different degrees of Floquet theory utilization, the fidelity of the resulting controlled gates surpasses that of the original reference, and it exhibits high robustness against Rabi error in two qubits and detuning error in the control qubit. Our method only uses encoding in the ground states, and compared to the original scheme using Rydberg state for encoding, it is less susceptible to environmental interference, making it more practical to implement. Therefore, our approach may have broader applications or potential for further expansion of geometric quantum computation with neutral atoms.
Soft pattern of gravitational Rutherford scattering from heavy target mass expansion
Authors: Jia Yu , Pan Jichen , Zhang Jia-Yue
Published: July 2024

We investigate the soft behavior of the tree-level Rutherford scattering processes mediated via $t$-channel one-graviton exchange. We consider two types of Rutherford scattering processes, {\it e.g.}, a low-energy massless structureless projectile (up to spin-$1$) hits a static massive composite particle carrying various spins (up to spin-$2$), and a slowly-moving light projectile hits a heavy static composite target. The unpolarized cross sections in the first type are found to exhibit universal forms at the first two orders in $1/M$ expansion, yet differ at the next-to-next-to-leading order, though some terms at this order still remain universal or depend on the target spin in a definite manner. The unpolarized cross sections in the second type are universal at the lowest order in projectile velocity expansion and through all orders in $1/M$, independent of the spins of both projectile and target. The universality partially breaks down at relative order-$v^2/M^2$, albeit some terms at this order still depend on the target spin in a specific manner.Content from this work may be used under the terms of the Creative Commons Attribution 3.0 licence. Any further distribution of this work must maintain attribution to the author(s) and the title of the work, journal citation and DOI. Article funded by SCOAP3 and published under licence by Chinese Physical Society and the Institute of High Energy Physics of the Chinese Academy of Science and the Institute of Modern Physics of the Chinese Academy of Sciences and IOP Publishing Ltd.
Inferring the spin distribution of binary black holes using deep learning
Authors: Tang 唐 Li 丽 , Fan 范 Xi-Long 锡龙
Published: July 2024

The spin characteristics of black holes offer valuable insights into the evolutionary pathways of their progenitor stars. This is crucial for understanding the broader population properties of black holes. Traditional hierarchical Bayesian inference techniques employed to discern these properties often demand substantial time, and consensus regarding the spin distribution of binary black hole (BBH) systems remains elusive. In this study, leveraging observations from GWTC-3, we adopted a machine learning approach to infer the spin distribution of black holes within BBH systems. Specifically, we developed a deep neural network (DNN) and trained it using data generated from a Beta distribution. Our training strategy, involving the segregation of data into 10 bins, not only expedites model training but also enhances the versatility and adaptability of the DNN to accommodate the growing volume of gravitational wave observations. Utilizing Monte Carlo-bootstrap (MC-bootstrap) to generate observation-simulated samples, we derived spin distribution parameters:

for the larger BH sample and

for the smaller BH sample. Within our constraints, the distributions of component spin magnitudes suggest the likelihood of both black holes in the BBH merger possessing non-zero spin.
Photometric Studies of EV Cnc and AH Cnc in the Open Cluster M67
Authors: G. Mamatha Rani , Sriram K. , Lahiri Deblina , A. Vijaya,
Published: July 2024

Contact binaries at various stages of evolution unveil various operating mechanisms that drive them. We report the photometric and period variation analysis of two contact binaries EV Cnc and AH Cnc in open cluster M67. We observed the cluster from the JCBT 1.3 m telescope and utilized TESS and Kepler observations. The photometric solutions of EV Cnc and AH Cnc revealed a mass ratio of q ∼ 0.41 and ∼0.15 with an inclination of i = 42° and 87° respectively. These solutions suggest that EV Cnc is probably a semi-detached and AH Cnc is a deep low-mass ratio contact binary. The study of O − C variation analysis indicates that for both systems, the period is increasing which suggests the mass transfer is occurring from secondary to primary. In the case of AH Cnc and based on simulations by randomly varying the time of minima to fit the LITE solution, we noted the third body orbital period to be around P
3 = 26.82 ± 2.54 yr, which is different from earlier reported values and conclude that future observations are required to confirm this scenario. We compare these two systems with other similar contact binaries to get an estimate of the final configuration of the respective systems.
Understanding the Activity Performance of Comets 38P/Stephan-Oterma, 64P/Swift-Gehrels and C/2017 M4 (ATLAS) through Broadband Photometric Observations
Authors: Zhang Xuan , Liu Jin-Zhong , Wang Le-Tian
Published: July 2024

In this work, we report observations of three comets: 38P/Stephan-Oterma, 64P/Swift-Gehrels, and C/2017 M4 (ATLAS), conducted with the Nanshan one-meter wide-field telescope in 2018 August and November, and 2019 January. We extracted morphological features through image enhancement techniques and calculated the dust activity parameter, Afρ, along with dust mass loss rates and coma color indices using broadband photometric data. Our morphological analysis uncovered a spectrum of dust characteristics among the observed comets, ranging from a significant twisted structure in comet 38P/Stephan-Oterma’s coma to the regular coma envelope surrounding comet 64P/Swift-Gehrels. The Af
ρ values varied between 148.8 ± 0.3 cm for 64P/Swift-Gehrels and 1118.5 ± 6.2 cm for C/2017 M4 (ATLAS) (measured within a reference aperture radius of ρ = 6″), indicating a range from moderate to high activity levels. Dust mass loss rates were estimated from 328.1 kg s−1 for comet 64P/Swift-Gehrels to 1395.5 kg s−1 for comet C/2017 M4 (ATLAS). The color indices of comets 38P/Stephan-Oterma and C/2017 M4 (ATLAS) closely resemble the average colors of active short-period comets and active long-period comets, respectively. In contrast, 64P/Swift-Gehrels exhibits a significantly bluer hue than typical Jupiter family comets.
Defects evolution in n-type 4H-SiC induced by electron irradiation and annealing
Authors: Xiong Huifan , Lu Xuesong , Gao Xu , Yan Yuchao , Liu Shuai , Song Lihui , Yang Deren , Pi Xiaodong
Published: July 2024

Radiation damage produced in 4H-SiC by electrons of different doses is presented by using multiple characterization techniques. Raman spectra results indicate that SiC crystal structures are essentially impervious to 10 MeV electron irradiation with doses up to 3000 kGy. However, irradiation indeed leads to the generation of various defects, which are evaluated through photoluminescence (PL) and deep level transient spectroscopy (DLTS). The PL spectra feature a prominent broad band centered at 500 nm, accompanied by several smaller peaks ranging from 660 to 808 nm. The intensity of each PL peak demonstrates a linear correlation with the irradiation dose, indicating a proportional increase in defect concentration during irradiation. The DLTS spectra reveal several thermally unstable and stable defects that exhibit similarities at low irradiation doses. Notably, after irradiating at the higher dose of 1000 kGy, a new stable defect labeled as R
2 (Ec − 0.51 eV) appeared after annealing at 800 K. Furthermore, the impact of irradiation-induced defects on SiC junction barrier Schottky diodes is discussed. It is observed that high-dose electron irradiation converts SiC n-epilayers to semi-insulating layers. However, subjecting the samples to a temperature of only 800 K results in a significant reduction in resistance due to the annealing out of unstable defects.
Reconfigurable and polarization-dependent optical filtering for transflective full-color generation utilizing low-loss phase-change materials
Authors: Deng Shuo , Cui Mengxi , Jiang Jingru , Wang Chuang , Cheng Zengguang , Sun Huajun , Xu Ming , Tong Hao , He Qiang , Miao Xiangshui
Published: July 2024

All-dielectric metasurface, which features low optical absorptance and high resolution, is becoming a promising candidate for full-color generation. However, the optical response of current metamaterials is fixed and lacks active tuning. In this work, we demonstrate a reconfigurable and polarization-dependent active color generation technique by incorporating low-loss phase change materials (PCMs) and CaF2 all-dielectric substrate. Based on the strong Mie resonance effect and low optical absorption structure, a transflective, full-color with high color purity and gamut value is achieved. The spectrum can be dynamically manipulated by changing either the polarization of incident light or the PCM state. High transmittance and reflectance can be simultaneously achieved by using low-loss PCMs and substrate. The novel active metasurfaces can bring new inspiration in the areas of optical encryption, anti-counterfeiting, and display technologies.
Dual-phase coexistence enables to alleviate resistance drift in phase-change films
Authors: Wu Tong , Chen Chen , Zhu Jinyi , Wang Guoxiang , Dai Shixun
Published: July 2024

The amorphous phase-change materials with spontaneous structural relaxation leads to the resistance drift with the time for phase-change neuron synaptic devices. Here, we modify the phase change properties of the conventional Ge2Sb2Te5 (GST) material by introducing an SnS phase. It is found that the resistance drift coefficient of SnS-doped GST was decreased from 0.06 to 0.01. It can be proposed that the origin originates from the precipitation of GST nanocrystals accompanied by the precipitation of SnS crystals compared to single-phase GST compound systems. We also found that the decrease in resistance drift can be attributed to the narrowed bandgap from 0.65 to 0.43 eV after SnS-doping. Thus, this study reveals the quantitative relationship between the resistance drift and the band gap and proposes a new idea for alleviating the resistance drift by composition optimization, which is of great significance for finding a promising phase change material.
Helium plasma operations on ASDEX Upgrade and JET in support of the non-nuclear phases of ITER
Authors: Hakola A. , Balden M. , Baruzzo M. , Bisson R. , Brezinsek S. , Dittmar T. , Douai D. , Dunne M. , Garzotti L. , Groth M. , Henriques R. , Horvath L. , Jepu I. , Joffrin E. , Kappatou A. , Keeling D. , Krieger K. , Labit B. , Lennholm M. , Likonen J. , Loarte A. , Lomas P. , Lowry C. , Maslov M. , Matveev D. , Pitts R.A. , Plank U. , Rasinski M. , Ryan D. , Saarelma S. , Silburn S. , Solano E.R. , Suttrop W. , Tala T. , Tsitrone E. , Vianello N. , Wauters T. , Widdowson A. , Wischmeier M. , Exploitation Team the EUROfusion Tokamak , Team the ASDEX Upgrade ,   JET Contributors
Published: July 2024

For its initial operational phase, ITER has until recently considered using non-nuclear hydrogen (H) or helium (He) plasmas to keep nuclear activation at low levels. To this end, the Tokamak Exploitation Task Force of the EUROfusion Consortium carried out dedicated experimental campaigns in He on the ASDEX Upgrade (AUG) and JET tokamaks in 2022, with particular emphasis put on the ELMy H-mode operation and plasma-wall interaction processes as well as comparison to H or deuterium (D) plasmas. Both in pure He and mixed He + H plasmas, H-mode operation could be reached but more effort was needed to obtain a stable plasma scenario than in H or D. Even if the power threshold for the LH transition was lower in He, entering the type-I ELMy regime appeared to require equally much or even more heating power than in H. Suppression of ELMs by resonant magnetic perturbations was studied on AUG but was only possible in plasmas with a He content below 19%; the reason for this unexpected behaviour remains still unclear and various theoretical approaches are being pursued to properly understand the physics behind ELM suppression. The erosion rates of tungsten (W) plasma-facing components were an order of magnitude larger than what has been reported in hydrogenic plasmas, which can be attributed to the prominent role of He2+ions in the plasma. For the first time, the formation of nanoscale structures (W fuzz) was unambiguously demonstrated in H-mode He plasmas on AUG. However, no direct evidence of fuzz creation on JET was obtained despite the main conditions for its occurrence being met. The reason could be a delicate balance between W erosion by ELMs, competition between the growth and annealing of the fuzz, and coverage of the surface with co-deposits.
Numerical simulation of anti-icing cavity performance for an engine inlet lip
Authors: Guan Ning , Li Yiyan , Xu Ning , Xu Zhitai
Published: July 2024

In this paper, the hot air of the engine lip is the research object, and the three-dimensional model is established. Through the calculation and quantitative analysis of the effect of ice protection at different gas diversion speeds and gas diversion temperatures, the influence of the above parameters on the effectiveness of ice protection is obtained. It shows that the air velocity is from 10 m/s to 40 m/s, and the lowest temperature of the ice surface rises from 266.4 K to 286.2 K. When the air temperature increases from 100°C to 130°C, the lowest temperature of the ice surface rises from 286.2 K to 307.1 K. Therefore, when the air introduction speed is not less than 15 m/s and the flow temperature is not lower than 380 K, the effective anti-ice of the short chamber lip can be realized.
Analysis of fluid-structure coupling during the flapping of dragonfly hind wings under different flexible distributions
Authors: Yu Feng , Ye Xiaomei , He Guoyi
Published: July 2024

To investigate the influence of flexible distribution on the aerodynamic characteristics of a dragonfly hind wing during flapping flight, this study establishes a simplified plate model of the dragonfly hind wing based on the actual size, while neglecting the wrinkled microstructure. Six different flexible distribution patterns are proposed for the model. The overlapping grid technique is employed to achieve fluid-structure coupling calculations during the flapping motion of the dragonfly hind wing, by customizing the Young’s modulus in the solid region to represent different levels of flexibility. The results show that gradually increasing the flexibility along the chordwise direction of the dragonfly wing can induce a stronger leading-edge vortex during flapping, intensifying the accumulation of vorticity near the wingtip and resulting in a higher peak lift coefficient. The flexible wing has a positive impact on the formation and development of the trailing-edge vortex, leading to an increase in the thrust coefficient peak and time-averaged thrust coefficient of the dragonfly hind wing. Consequently, all aspects of the aerodynamic characteristics are significantly improved.