bluuebunny/crossref_metadata_2025_split huggingface dataset:
Ionization layer with collision-free atoms at the edge of partially to fully ionized plasmas
Authors: Benilov M S 
Published: April 2024

Abstract
When a hot arc spot has just formed on the cathode surface, e.g. in the course of arc ignition on a cold cathode, a significant part of the current still flows in the glow-discharge mode to the cold surface outside the spot. The near-cathode voltage continues to be high at all points of the cathode surface. The mean free path for collisions between the atoms and the ions within the plasma ball near the spot is comparable to, or exceeds, the thickness of the ionization layer, which is a part of the near-cathode non-equilibrium layer where the ion current to the cathode is generated. The evaluation of the ion current to the cathode surface under such conditions is revisited. A fluid description of the ion motion in the ionization layer is combined with a kinetic description of the atom motion. The resulting problem admits a simple analytical solution. Formulas for the evaluation of the ion current to the cathode for a wide range of conditions are derived and the possibilities of using these formulas to improve the accuracy of existing methods for modeling high-pressure arc discharges in relation to glow-to-arc transitions are discussed.
Laser ablation of thin SiN
x
layer coated on silicon wafer—evaluation of process performance for PERC solar cell application
Authors: Rana Pinal , Prasad Khatri Durga , Kottantharayil Anil , Marla Deepak 
Published: April 2024

Abstract
In fabricating passivated emitter and rear contact (PERC) solar cells, creating small openings on the SiN

x

coated silicon substrate to establish metal contacts necessitates using a nanosecond pulsed green laser for ablation. However, the thermal nature of laser ablation poses a challenge. Excessive nitrogen diffusion from SiN

x

into the silicon substrate can compromise the electrical performance of solar cells. Therefore, this study aims to comprehensively understand how laser parameters impact the electrical properties of such solar cells. PERC solar cell precursors were initially fabricated by ablating the SiN

x

layer at four laser fluences, each corresponding to different regimes: solid, liquid, vapor, and phase explosion. Subsequently, various optical, chemical, and electrical characterizations were conducted on the solar cell precursors. Complete PERC solar cells were also fabricated to measure quantum efficiency (QE). In the solid regime, SiN

x

removal is precise, with minimal thermal damage, resulting in a nitrogen concentration of approximately 0.15%. Photoluminescence count and carrier lifetime are notably higher by 21% in the solid regime compared to the explosive regime. The QE measurement at 984 nm quantitatively assesses rear-side recombination losses. Notably, 26% of the area exhibits a 56% QE in the solid state, while this number drops to around 22% in the explosive state. This decline can be attributed to increased thermal damage in the explosive regime, which augments recombination centers and diminishes the solar cell performance. PERC solar cells ablated in the solid regime showcase lower subsurface damage, superior electrical characteristics, and higher performance than those ablated in the explosive regime.
Vortex-glass transition and vortex pinning behavior in three-dimensional NbTiN epitaxial films
Authors: Han Zi-Yan , Jing Tian-Yu , Yang Jian , Cai Wen-Bo , Li Zhi-Qing 
Published: April 2024

Abstract
In the present paper, the vortex dynamics in two NbTiN epitaxial films have been explored via analyzing the current–voltage (I–V) curves measured at different temperatures and fields. The thicknesses of the two films are ∼50 and ∼100 nm, respectively, and they are three-dimensional (3D) with respect to superconductivity. The films transform from normal state to superconducting state with decreasing temperature at zero field, and the values of superconducting transition temperature

T
c

are 8.73 and 12.03 K for the ∼50- and ∼100-nm-thick films, respectively. When a magnetic field with magnitude

0.5

T
≲

μ
0

H
≲
7

T and perpendicular to the film plane is applied, the isothermal I–V data show a 3D vortex-glass (VG) scaling collapse at each field, suggesting that a 3D vortex-liquid phase to VG phase transition occurs in the NbTiN films. By analyzing the critical current density, we found that core pinning is the main pinning mechanism in the films. In addition, it is found that the normal point-like pinning dominates the pinning behavior at low field regime. While in the high field regime, besides the normal point-like pinning, other pinning mechanisms, such as Δκ pinning, also exist in the films. Our results not only provide strong experimental support for the occurrence of VG phase transition in conventional superconductors, but also provide fundamental information for the application of NbTiN films.
Steady-state entanglement production in a quantum thermal machine with continuous feedback control
Authors: Francesco Diotallevi Giovanni , Annby-Andersson Björn , Samuelsson Peter , Tavakoli Armin , Bakhshinezhad Pharnam 
Published: April 2024

Abstract
Quantum thermal machines can generate steady-state entanglement by harvesting spontaneous interactions with local environments. However, using minimal resources and control, the entanglement is typically weak. Here, we study entanglement generation in a two-qubit quantum thermal machine in the presence of a continuous feedback protocol. Each qubit is measured continuously and the outcomes are used for real-time feedback to control the local system-environment interactions. We show that there exists an ideal operation regime where the quality of entanglement is significantly improved, to the extent that it can violate standard Bell inequalities and uphold quantum teleportation. In agreement with (Khandelwal et al 2020 New J. Phys.
22 073039), we also find, for ideal operation, that the heat current across the system is proportional to the entanglement concurrence. Finally, we investigate the robustness of entanglement production when the machine operates away from the ideal conditions.
Uncertainty relation and the constrained quadratic programming
Authors: Zhang Lin , Wu Dade , Zhao Ming-Jing , Nan Hua 
Published: April 2024

Abstract
The uncertainty relation is a fundamental concept in quantum theory, plays a pivotal role in various quantum information processing tasks. In this study, we explore the additive uncertainty relation pertaining to two or more observables, in terms of their variance, by utilizing the generalized Gell-Mann representation in qudit systems. We find that the tight state-independent lower bound of the variance sum can be characterized as a quadratic programming problem with nonlinear constraints in optimization theory. As illustrative examples, we derive analytical solutions for these quadratic programming problems in lower-dimensional systems, which align with the state-independent lower bounds. Additionally, we introduce a numerical algorithm tailored for solving these quadratic programming instances, highlighting its efficiency and accuracy. The advantage of our approach lies in its potential ability to simultaneously achieve the optimal value of the quadratic programming problem with nonlinear constraints but also precisely identify the extremal state where this optimal value is attained. This enables us to establish a tight state-independent lower bound for the sum of variances, and further identify the extremal state at which this lower bound is realized.
Recent advancements in supercapacitors and their charge storage mechanism and progress in transition metal sulfide-based electrodes
Authors: Khan Mohd Shakir , Shariq Mohammad , Bouzgarrou Souhail Mohammed , Azooz Rehab E , Ali Syed kashif , Ghaly Waleed A , Hassan K F 
Published: April 2024

Abstract
Efficient energy storage strategies have become a major priority in the last few years. Transition metal sulphides are popularly known as attractive electrode materials or supercapacitors due to their high theoretical capacitance, excellent electrical conductivity, and favourable redox properties. Through compositional and structural engineering, some transition metal sulphides like Mn, V, Co, Fe, Cu, Ni, Mo, Zn, W, and Sn have shown substantial improvements in electrochemical performance. Composite engineering and morphological control are two of the key strategies employed to improve the TMS electrode’s electrochemical performance. Excellent electrochemical TMSs address the issues of slow kinetics, poor stability, and large volume expansions. This study reveal optimised TMSs potential to transform supercapacitor applications and provides viable approaches to conquer current hurdles to shape the forthcoming century’s high-performance and low-cost energy storage technology. The effects of composite engineering and morphological control on the ultimate electrochemical performance of the electrode materials are the primary focus of this investigation. Challenges to the further advancement of transition metal sulphide-based electrode materials are also explored in this article. Critical approaches to resolving significant issues in our current understanding of the kinetic and mechanistic perspectives of charge storage processes, i.e., slow kinetics, poor stability, and volume expansions, are also highlighted. Ultimately, future potentials, challenges, and possible solutions to tackle these problems are broadly discussed.
Optical properties of the O3+-ion implanted and femtosecond-laser ablated ridge waveguide in the Er3+-doped germanate glass
Authors: Zhao Jie , Ni Xiao , Huo Yuan-Yang , Sun Wang , Zhang Liao-Lin , Liu Chun-Xiao 
Published: April 2024

Abstract
Er3+-doped germanate glass is a kind of polyfunctional material for optical and photonic applications. The work reports on the preparation and properties of O3+-ion implanted and femtosecond-laser ablated Er3+-doped germanate glass optical ridge waveguide. The energy is 6.0 MeV and the fluence is 5 × 1014 ions cm−2 for the O3+-ion implantation. The pulse energy and the scanning speed of the femtosecond-laser ablation are 3 μJ and 50 μm s−1, respectively. The SRIM 2013 is used to calculate the vacancy profile induced by the implantation in the Er3+-doped germanate glass for the physical mechanisms of the waveguide formation. The optical microscopy images of the cross-section of the waveguide are captured by the Nikon microscope. The light-guiding properties of the ion-implanted and laser-ablated waveguides are studied by the end-face coupling system. The ridge waveguide has been produced by combining the FS ablation with ion implantation technologies for the first time in the Er3+-doped germanate glass. The propagation of light field indicates that it has the potential for photonics applications based on the planar and ridge Er3+-doped germanate glass waveguides.
Relic neutrino decay solution to the excess radio background
Authors: Bhupal Dev P.S. , Bari Pasquale Di , Martínez-Soler Ivan , Roshan Rishav 
Published: April 2024

Abstract
The excess radio background detected by ARCADE 2 represents a puzzle within the standard
cosmological model. There is no clear viable astrophysical solution, and therefore, it might
indicate the presence of new physics. Radiative decays of a relic neutrino ν_i (either i=1,
or i=2, or i=3) into a sterile neutrino ν_ s, assumed to be quasi-degenerate, provide
a solution that currently evades all constraints posed by different cosmological observations and
reproduces very well the ARCADE 2 data. We find a very good fit to the ARCADE 2 data with best
fit values τ_i = 1.46 × 10^21 s and Δ m_i = 4.0 × 10^-5
eV, where τ_i is the lifetime and Δ m_i is the mass difference between the
decaying active neutrino and the sterile neutrino. On the other hand, if relic neutrino decays do
not explain ARCADE 2 data, then these place a stringent constraint Δ m_i^3/2τ_i
≳ 2 × 10^14 eV^3/2 s in the range 1.4 × 10^-5 eV<Δ m_i < 2.5 × 10^-4 eV. The solution also predicts a stronger 21 cm
absorption global signal than the predicted one from the ΛCDM model, with a contrast
brightness temperature T_21 = -238^+21_-20 mK (99% C.L.) at redshift z≃
17. This is in mild tension with the even stronger signal found by the EDGES collaboration,
T_21 = - 500^+200_-500 mK, suggesting that this might have been overestimated,
possibly receiving a contribution from some unidentified foreground source.
Observational constraints on extended Proca-Nuevo gravity and cosmology
Authors: Anagnostopoulos Fotios K. , Saridakis Emmanuel N. 
Published: April 2024

Abstract
We confront massive Proca-Nuevo gravity with cosmological
observations. The former is a non-linear theory involving a massive spin-1
field, that can be extended incorporating operators of the Generalized Proca
class, and when coupled to gravity it can be covariantized in a way that
exhibits consistent and ghost-free cosmological solutions, without experiencing
instabilities and superluminalities at the perturbative level.
When applied at a cosmological framework it induces extra terms in the
Friedmann equations, however due to the special non-linear construction the
field is eliminated in favor of the Hubble function. Thus, the resulting
effective dark energy sector is dynamical, however it contains
the same number of free parameters with the ΛCDM concordance model.
We use data from Supernovae Ia (SNIa) and Cosmic Chronometers
(CC) observations and we construct the corresponding likelihood-contours for
the free parameters. Interestingly enough, application of various information
criteria, such as AIC, BIC and DIC, shows that the scenario of massive
Proca-Nuevo gravity, although having exactly the same number of free
parameters
with ΛCDM paradigm, it is more efficient in fitting the data.
Finally, the reconstructed dark-energy equation-of-state parameter
shows statistical compatibility
with the model-independent, data-driven reconstructed one.
Probing ultralight tensor dark matter with the stochastic gravitational-wave background from advanced LIGO and Virgo's first three observing runs
Authors: Guo Rong-Zhen , Jiang Yang , Huang Qing-Guo 
Published: April 2024

Abstract
Ultralight bosons are attractive dark-matter candidates and appear in various scenarios beyond standard model. They can induce superradiant instabilities around spinning black holes (BHs), extracting the energy and angular momentum from BHs, and then dissipate through monochromatic gravitational radiation, which become promising sources of gravitational wave detectors. In this letter, we focus on massive tensor fields coupled to BHs and compute the stochastic gravitational wave backgrounds emitted by these sources. We then undertake a search for this background within the data from LIGO/Virgo O1∼O3 runs. Our analysis reveals no discernible evidence of such signals, allowing us to impose stringent limits on the mass range of tensor bosons. Specifically, we exclude the existence of tensor bosons with masses ranging from 4.0 × 10-14 to 2.0 × 10-12 eV at 95% confidence level.
Triplet scalar flavored leptogenesis with spontaneous CP violation
Authors: Chongdar Sreerupa , Mishra Sasmita 
Published: April 2024

Abstract
The inclusion of two triplet scalars in the Standard Model (SM) enables to accommodate neutrino mass generation as well as baryogenesis through leptogenesis. One of the
essential ingredients of leptogenesis is the violation of
charge conjugation and parity (CP) symmetry in lepton number violating decays of the triplet scalars. We work on the promising sector of spontaneous CP violation (SCPV) which is manifested by the involvement of one scalar singlet and two scalar fields, added to the SM. The predictive
aspect of the model is accomplished by imposing A
4 × Z
4 symmetry which results in the traditional tribimaximal mixing pattern. With updated data on neutrino oscillation, we study the parameter space of the model.
The phase of the complex vacuum expectation value (VEV) of the singlet scalar acts as the common source of
CP violation in both low and high energy sectors.
Due to the flavor symmetry of the model, required baryon asymmetry cannot be accomplished via unflavored leptogenesis. In the temperature regime, [109, 1012] GeV when flavor effects become important in the study of leptogenesis, it is shown that baryogenesis is achievable. The rich flavor interplay is explored through the study of the density matrix equations. We also study the interplay of hierarchical branching ratios of the decay of the triplet scalars and SCPV phase to accommodate the required CP asymmetry to account for the final baryon asymmetry in the observational range. Considering all possible mass hierarchies among the triplet scalars, the flavor structure of the triplet Yukawa couplings results in different scales of leptogenesis.
Novel tests of gravity using nano-Hertz
stochastic gravitational-wave background signals
Authors: Cannizzaro Enrico , Franciolini Gabriele , Pani Paolo 
Published: April 2024

Abstract
Gravity theories that modify General Relativity in the slow-motion regime can introduce nonperturbative corrections to the stochastic gravitational-wave background (SGWB) from supermassive black-hole binaries in the nano-Hertz band,
while not affecting the quadrupolar nature of the gravitational-wave radiation and remaining perturbative in the highly-relativistic regime, as to satisfy current post-Newtonian (PN) constraints. We present a model-agnostic formalism to map such theories into a modified tilt for the SGWB spectrum, showing that negative PN corrections (in particular -2PN) can alleviate the tension in the recent pulsar-timing-array data if the detected SGWB is interpreted as arising from supermassive binaries. Despite being preliminary, current data have already strong constraining power, for example they set a novel (conservative) upper bound on theories with time-varying Newton's constant (a -4PN correction) at least at the level of Ġ/G ≲ 10^-5 yr^-1 for redshift z=[0.1÷1]. We also show that NANOGrav data are best fitted by a broken power-law interpolating between a dominant -2PN or -3PN modification at low frequency, and the standard general-relativity scaling at high frequency. Nonetheless, a modified gravity explanation should be confronted with binary eccentricity, environmental effects, nonastrophysical origins of the signal, and scrutinized against statistical uncertainties. These novel tests of gravity will soon become more stringent when combining all pulsar-timing-array facilities and when collecting more data.
Using Schrödinger cat quantum state for detection of a given phase shift
Authors: Gorshenin V L 
Published: April 2024

Abstract
We show that injecting a light pulse prepared in the Shrödinger cat quantum state into the dark port of a two-arm interferometer, it is possible to detect a given phase shift unambiguously. The value of this phase shift is inversely proportional to the amplitudes of both the classical carrier light and the Shrödinger cat state. However, an unconventional detection procedure is required for this purpose. By measuring the number of photons at the output dark port, it is possible to detect the phase shift with a vanishing ‘false positive’ probability. The ‘false negative’ probability in this case decreases as the amplitude of the Schrödinger cat state increases and, for reasonable values of this amplitude, can be made less than about 0.1.
ICRH operations during the JET tritium and DTE2 campaigns
Authors: Jacquet P. , Dumortier P. , Lerche E. , Monakhov I. , Noble C. , Roberts J. , Sheikh H. , Goodyear A. , Balshaw N. , Ciric D. , Lobel R. , Lomas P. , Lowry C. , Rimini F. , Silburn S. , Horton L. 
Published: April 2024

Abstract
The JET-ILW pure tritium and deuterium–tritium (DTE2) experimental campaigns took place in 2021–2022. Tritium (T) and deuterium–tritium (D–T) operations present challenges not encountered in present day tokamaks (Horton et al 2016 Fusion Eng. Des.
109–111 925–36). This contribution focuses on ion cyclotron resonance heating (ICRH) operations in tritium and deuterium–tritium plasmas, starting with a summary of the program of improvements to the ICRH system which spanned a few years prior to these experiments. Procedures were implemented to address specific constraints from tritium and deuterium–tritium operations (tritium safety and reduced access to the RF generator area) and increase the system reliability and power availability during plasma pulses. Operation of the upgraded real time RF power control system that maximises the launched power while taking into account limitations from the system or antenna coupling is described. We also report on the result from dedicated pulses performed to assess the potential harmful impact of the 2nd harmonic tritium resonance in the plasma, close to the inner wall, when using the standard central hydrogen minority ICRH scheme. During DTE2, the ITER-like antenna was not used because water leaked from an in-vessel capacitor into the vessel on day-2 of the experimental campaign. The lessons learnt from this incident are highlighted. Finally, the ICRH plant adjustments required to safely perform ion cyclotron wall cleaning discharges are described.
Creation and manipulation of optical Meron topologies in tightly focused electromagnetic field
Authors: Lei Haomai , Luo Bin , Hu Jianfei , Wang Jiming , Wu Tong , Liu Youwen 
Published: April 2024

Abstract
The optical topology, which serves as a stable spatial electromagnetic structure, offers a new dimension for applications in the field of optical information processing, transmission, and storage. In recent years, there has been an increasing focus on these spatially structured light fields. By reversing the radiation of orthogonal dipole pairs, we propose an approach to generate Meron topologies within the focused light field while also investigating the evolution of the Meron structure along the longitudinal axis. Through introducing a dipole placed along the z-axis, we achieve precise positioning and fine adjustment of the topological center. The stability of Meron under a high numerical aperture objective lens (NA = 0.95) can be effectively demonstrated.
Bandgap variation in semiconductor thin films of the solid solution (CdTe)1-x(In2Te3)x deposited by RF sputtering
Authors: Meléndez-Lira Miguel , Jiménez-Sandoval Sergio , Zapata-Torres Martin , García-Sotelo Alejandra , Hernández Rodríguez Eric Noé , Hernández-Hernández Arturo 
Published: April 2024

Abstract
(CdTe)1-x(In2Te3)x films, with 0.1 ≤ x ≤ 1, were deposited by radio frequency sputtering on glass substrates employing different targets, prepared for each composition. The x-ray diffractograms were consistent with substitutional In incorporation into the CdTe lattice up to a value of x = 0.2. For higher In contents, the films presented structural disorder without reaching full amorphous characteristics. For x = 1, corresponding to In2Te3, preferential growth was observed. The bandgap of the solid solution varied between 1.46 and 1.2 eV, reaching a maximum of 1.58 eV for x = 0.3. For both end binary compounds the random incorporation of a third chemical element produced a significant broadening of the Raman modes consistent with a reduction of the lifetime of the optical phonons. The electrical resistivity was dependent on the Cd concentration reaching a minimum for x = 0.8.