bluuebunny/crossref_metadata_2025_split huggingface dataset:
Investigation of PCVSi
− defect in 4H–SiC as a candidate for a qubit
Authors: Sun Lei , Zhang Wenxu , Peng Bin , Zhang Wanli 
Published: September 2024

Abstract
Exploration of spin defects in semiconductors for possible qubits encourages the development of the quantum field. Silicon carbide (SiC) is a suitable platform to carry spin defects, due to its excellent electrical, mechanical and optical properties, together with its convenience for crystallographic growth and doping processes. In this study, a negatively charged phosphorus-vacancy (PCVSi
−) defect, consisting of a silicon vacancy and nearby substitution of a phosphorus atom to a carbon atom in 4H–SiC, is investigated by first-principles calculations. This defect is demonstrated to possess a high spin (S = 1) with relatively low formation energy. Computed zero-phonon line energy and zero-field splitting parameters of this defect are close to those of neutral divacancy (VCVSi
0), negatively charged nitrogen-vacancy center (NCVSi
−) and some other color centers, which indicate a similarity of both optical and spin properties among them. Moreover, the electron spin coherence time of this defect turns out to be 1.15–1.40 ms. Such a long coherence time provides the defect with reliability for quantum information processing. Our results show that the PCVSi
− defect can be a promising candidate for a qubit.
An in-situ tool wear measurement method based on super-pixels and enhanced corner detection algorithm
Authors: Wang Zhizhuo , Wang Guofeng , Wang Haotian , Li Xuwei , Yan Shuang , Sheng Yanliang 
Published: September 2024

Abstract
In robotic milling scenarios, lighting conditions that are difficult to optimize and random angles of the cutting edge often lead to inaccuracies in in-situ tool wear detection. This paper proposes a method based on machine vision to accurately measure the wear parameters of end mills. Firstly, a cropping algorithm based on polar coordinate transformation is introduced to extract the Region of Interest from the flank face of the tool bottom. Subsequently, a segmentation algorithm that combines super-pixels and multi-thresholding is proposed, with a focus on maintaining the connectivity of the damage regions during segmentation. Finally, an algorithm based on improved corner detection is presented to reconstruct the tool breakage region. Experimental results demonstrate that the proposed method achieves precise tool wear measurement despite random cutting edge angles and exhibits good robustness under varying lighting conditions. In the in-situ detection experiment, the method achieved a measurement accuracy of 97% for maximum wear width and 95% for wear area, indicating the effectiveness of the proposed method.
Modeling martensitic transformation temperatures in Zirconia–Ceria solid solutions using machine learning interatomic potentials
Authors: Rettenmaier Owen T , Gabriel Joshua J , Patala Srikanth 
Published: September 2024

Abstract
Shape memory ceramics (SMCs), while exhibiting high strength, sizeable recoverable strain, and substantial energy damping, tend to shatter under load and have low reversibility. Recent developments in SMCs have shown significant promise in enhancing the reversibility of the shape memory phase transformation by tuning the lattice parameters and transformation temperatures through alloying. While first-principles methods, such as density functional theory (DFT), can predict the lattice parameters and enthalpy at zero Kelvin, calculating the transformation temperature from free energy at high temperatures is impractical. Empirical potentials can calculate transformation temperatures efficiently for large system sizes but lack compositional transferability. In this work, we develop a model to predict transformation temperatures and lattice parameters for the Zirconia–Ceria solid solutions. We construct a machine learning inter-atomic potential (MLIAP) using an initial dataset of DFT simulations, which is then iteratively expanded using active learning. We utilize reversible scaling to compute the free energy as a function of composition and temperature, from which the transformation temperatures are determined. These transformation temperatures match experimental trends and accurately predict the phase boundary. Finally, we compare other relevant design parameters (e.g. transformation volume change) to demonstrate the applicability of MLIAPs in designing SMCs.
Selective area epitaxy of in-plane HgTe nanostructures on CdTe(001) substrate
Authors: Chaize N , Baudry X , Jouneau P-H , Gautier E , Rouvière J-L , Deblock Y , Xu J , Berthe M , Barbot C , Grandidier B , Desplanque L , Sellier H , Ballet P 
Published: September 2024

Abstract
Semiconductor nanowires (NWs) are believed to play a crucial role for future applications in electronics, spintronics and quantum technologies. A potential candidate is HgTe but its sensitivity to nanofabrication processes restrain its development. A way to circumvent this obstacle is the selective area growth technique. Here, in-plane HgTe nanostructures are grown thanks to selective area molecular beam epitaxy on a semi-insulating CdTe substrate covered with a patterned SiO2 mask. The shape of these nanostructures is defined by the in-plane orientation of the mask aperture along the <110>, <1

1
¯

0>, or <100> direction, the deposited thickness, and the growth temperature (GT). Several micron long in-plane NWs can be achieved as well as more complex nanostructures such as networks, diamond structures or rings. A good selectivity is achieved with very little parasitic growth on the mask even for a GT as low as 140 °C and growth rate up to 0.5 monolayer per second. For <110> oriented NWs, the center of the nanostructure exhibits a trapezoidal shape with {111}B facets and two grains on the sides, while <1

1
¯

0> oriented NWs show {111}A facets with adatoms accumulation on the sides of the top surface. Transmission electron microscopy observations reveal a continuous epitaxial relation between the CdTe substrate and the HgTe NW. Measurements of the resistance with four-point scanning tunneling microscopy indicates a good electrical homogeneity along the main NW axis and a thermally activated transport. This growth method paves the way toward the fabrication of complex HgTe-based nanostructures for electronic transport measurements.
Non-homogeneous initial boundary value problems and small data scattering of the Hirota equations posed on the half line
Authors: Li Shenghao , Mu Chunlai , Zhou Deqin 
Published: September 2024

Abstract
This paper deals with the well-posedness problems and scattering property of the Hirota equations posed on the right half line. We first prove the global well-posedness of the Hirota equations in three different solution spaces, including Lp
-Lq
and Bourgain related spaces, for the initial data in

H
s

(

R

+

)

with the index s being in

[

1
4

,
+
∞
)
∖
{

Z

+

1
2

}

,

[
0
,

1
4

)

and

(

−
1

4

,
0
)

, separately. The global solution is proved in different solution spaces with different techniques based on different ranges of s. Then we prove that the Hirota equation posed on the half line admits the scattering property in

L
2

(

R

+

)

if the initial data exponentially decays at infinity. As far as we know, this is the first scattering result for dispersive type equations posed on the half-line although there are numerous and wonderful scattering results for dispersive equations posed on the whole domain. The key and new ingredient in this paper is to construct rotation-rescaling transformations on the Hirota equations which lead to complex-valued gKdV equations and KdV-Burgers equations. We apply the inhomogeneous and homogeneous boundary operator estimates as well as the regularity of the solution space for complex-valued gKdV equations and KdV-Burgers equations to obtain well-posedness and scattering property.
Trace formulas revisited and a new representation of KdV solutions with short-range initial data
Authors: Rybkin Alexei 
Published: September 2024

Abstract
We put forward a new approach to Deift-Trubowitz type trace formulas for the 1D Schrodinger operator with potentials that are summable with the first moment (short-range potentials). We prove that these formulas are preserved under the KdV flow whereas the class of short-range potentials is not. Finally, we show that our formulas are well-suited to study the dispersive smoothing effect.
Influence of electron cyclotron current drive on the pressure crashes caused by the 2/1 double tearing modes
Authors: Li J Y , Zhang W , Liu Z X , Ma Z W , Long F F , Liu Y J , Deng C C , Li P C , Yang K N , Yin X Y , Hu R Z , Zhao Y A , Li H , Xie J L , Lan T , Mao W Z , Liu A D , Zhou C , Ding W X , Zhuang G , Liu W D 
Published: September 2024

Abstract
A module with self-consistent evolution of driven current is developed and coupled with the resistive-MHD equations in the three-dimensional, toroidal, and nonlinear simulation code (CLT). The driven current equation is solved with a second-order accuracy symmetric scheme, which exhibits good conservation properties. With the new module, we find that the driven current can self-consistently concentrate inside the magnetic island when the parallel diffusion of the driven current is sufficiently large. The efficiency of the driven current on tearing mode suppression will then be much higher than those with stationary distributions. With the new module, the influence of electron cyclotron current drive (ECCD) on the nonlinear evolution of the 2/1 double tearing modes (DTMs) is investigated. When co-ECCD deposits on the outer resonant surface, the local magnetic shear is reduced, and the growth rates of the DTMs decrease; if ctr-ECCD deposits on the outer resonant surface, the local magnetic shear increases, and the DTMs become more unstable. However, things will be different if ECCD deposits on the inner resonant surface since the local magnetic shear is negative. The co-ECCD deposited on the inner resonant surface increases the negative shear and then promotes the growth of the DTMs; while the ctr-ECCD suppresses the DTMs. It is also found that the off-axis and central pressure crashes associated with the 2/1 DTMs can be converted to each other by properly depositing the driven current. To convert a central crash to an off-axis crash, the co-ECCD should be deposited on the outer resonant surface, or the ctr-ECCD deposited on the inner resonant surface. While, the co-ECCD should be deposited on the inner rational surface, or the ctr-ECCD deposited on the outer rational surface to convert an off-axis crash to a central crash. The co- or ctr-ECCD should be larger than a threshold for such transitions, and the threshold value is mainly determined by the location of the inner resonant surface.
Study of the evolution of density and particle transport during density relaxation phase after pellet fueling on the EAST tokamak
Authors: Nan K B , Hou J L , Zhang J , Chu Y Q , Hao B L , Li P , He Y F , Yuan J S , Geng J S , Wu X H , Si Z Y , Wang S X , Zhou Z , Qiu H T , Cao B , Zhao H L , Zuo G Z , Hu J S ,   EAST Team
Published: September 2024

Abstract
The impact of pellet injection depth on particle transport characteristics and density profile evolution during the post-pellet density relaxation phase is investigated on the experimental advanced superconducting tokamak. Experiments were conducted under similar background plasma conditions and the results showed that variations in pellet deposition depths led to differences in density profiles despite comparable core fueling efficiencies. By computing the effective particle transport coefficients immediately after the pellet injection, it is found that the differences in density profiles are mainly due to significantly different transport velocities in the inner region of ρ < 0.4. The potential influence of pellets on electrostatic turbulence in this region is investigated using the trapped gyro Landau fluid model and

CO
2

laser collective scattering diagnostics. The simulation suggests that the increase in transport coefficients following pellet injection is attributed to the destabilization of lower-k modes rather than the higher-k modes within the diagnostic measurement range.
Investigating the trade-off between BV stability and ESD robustness in the n-channel LDMOS devices
Authors: Liang Hailian , Li Liping , Liu Junliang , Lin Feng , Xu Chaoqi , Sun Jun , Gu Xiaofeng 
Published: September 2024

Abstract
The trade-off between breakdown voltage (BV) stability and electrostatic discharge (ESD) robustness in n-channel laterally diffused metal–oxide–semiconductor (nLDMOS) devices was investigated, by utilizing computer-aided design Technology Computer Aided Design (TCAD) simulations and charge-pumping measurements. The BV stability and ESD robustness were improved by enlarging the key parameter Lj of the drift region, and introducing the step-graded doping drift region, respectively. The proposed novel nLDMOS device demonstrates superior performance, exhibiting an excellent ESD robustness of 2.0 A and a minimal 2% BV degradation after 50 000 s of hot carrier injection stress, representing a significant advancement in balancing ESD protection and long-term reliability.
Modeling and characterization of low frequency noise in self-aligned top-gate coplanar IGZO thin-film transistors
Authors: Lee Su-Hyeon , Oh Chae-Eun , Lee Dong-Ho , Hwang Jin-Ha , Han Ye-Lim , Ko Younghyun , Jeong ChanYong , Ryu WonSang , Noh Jiyong , Park Kwon-Shik , Song Sang-Hun , Kwon Hyuck-In 
Published: September 2024

Abstract
A modified low-frequency noise (LFN) model was proposed to accurately estimate the quality of the gate dielectric in self-aligned top-gate (SA TG) coplanar structure indium–gallium–zinc oxide (IGZO) thin-film transistors (TFTs). The proposed LFN model was derived by modifying the conventional carrier number with correlated mobility fluctuation model considering the peculiar characteristics of SA TG coplanar IGZO TFTs such as the channel length reduction due to the diffusion of hydrogen atoms or oxygen vacancies from the source/drain to the channel, as well as the relatively large source/drain parasitic resistance. The proposed model was validated by demonstrating that the measured LFN values were in good agreement with the predicted values from the proposed model for all SA TG coplanar IGZO TFTs with SiO2 gate dielectrics deposited under different plasma-enhanced chemical vapor deposition (PECVD) power densities. The near-interface gate dielectric trap densities extracted from each TFT using the proposed LFN model revealed a clear increase as the PECVD power increased, which is considered a major cause of poor positive-bias-temperature-stress stability of the SA TG coplanar IGZO TFT with SiO2 gate dielectric deposited under high PECVD power conditions.
Investigation of a new group of low band-gap semiconducting double perovskite K2MgSnZ6 (Z = Cl, Br, & I) materials and their structural, electronic, mechanical, and optical behaviors via DFT study
Authors: Iqbal Javed , Ullah Habib , Ullah Naimat , Ullah Riaz , Iqbal Zafar , Ullah Saeed , Shahat Abdelaaty A 
Published: September 2024

Abstract
This study focuses on potassium based double perovskite materials, specifically a series of K2MgSnZ6 (Z = Cl, Br, & I) halide materials. For the investigated materials, all primary calculations were performed using the Full-Potential Linearized Augmented Plane-Wave (FP-LAPW) method, supported by density functional theory (DFT), and implemented in the WIEN2k code. The Gold-Schmidt tolerance factor values confirm the structural stability of the compounds, while the negative values of formation energy indicate the feasibility of experimental synthesis of the studied materials. The lattice constants were observed to increase as the halide element at the ‘Z’ position was replaced by one with a larger ionic radius. The recorded band-gap values were 2.60 eV, 2.00 eV, and 1.37 eV for K2MgSnCl6, K2MgSnBr6, and K2MgSnI6, respectively. After calculating the elastic constants for all K2MgSnZ6 (Z = Cl, Br, & I) materials, it was found that they satisfy the primary conditions for Born stability required for cubic-phase materials: (1) C11 > B > C12, (2) C11 + 2C12 > 0, (3) C11 > 0, (4) C44 > 0, and (5) C11–C12 > 0. The optical parameters of the K2MgSnZ6 (Z = Cl, Br, & I) double perovskite materials suggest that these materials could play a significant role in practical applications such as solar cells, UV detectors, and various optoelectronic devices.
Localization features near the interface with nonlinear properties separating the Kerr-type nonlinear medium and a linear graded-index medium
Authors: Savotchenko S E 
Published: September 2024

Abstract
Interface with nonlinear response between nonlinear medium and a linear graded-index medium is considered. Exact solutions to the nonlinear Schrödinger equation with the nonlinear delta-function potential and the linear spatial term are found. The solutions describe the localized states in the self-focusing and defocusing nonlinear media separated from linear graded-index medium by interface with nonlinear response. Localization features in dependence on signs of defect parameters are analyzed. It is shown that nonlinearity of the defect leads to the possibility of localization with the different signs of defect parameters. Localized states arise for all combinations of repulsing and attracting defect, and self-focusing and defocusing nonlinear response of the defect. Localized states characterized by an asymmetric distribution with two maxima appear due to the presence of a nonlinear response of the defect. Controlling the defect parameters allows adjusting the height of the field intensity at the interface between the media and the depth of localization.
Gravitational-wave background in bouncing models from semi-classical, quantum and string gravity
Authors: Ben-Dayan Ido , Calcagni Gianluca , Gasperini Maurizio , Mazumdar Anupam , Pavone Eliseo , Thattarampilly Udaykrishna , Verma Amresh 
Published: September 2024

AbstractWe study the primordial spectra and the gravitational-wave background (GWB) of three models of semi-classical, quantum or string gravity where the big bang is replaced by a bounce and the primordial tensor spectrum is blue: ekpyrotic universe with fast-rolling Galileons, string-gas cosmology with Atick-Witten conjecture and pre-big-bang cosmology. We find that the ekpyrotic scenario with Galileons does not produce a GWB amplitude detectable by present or third-generation interferometers, while the Atick-Witten-based string-gas model is ruled out in its present form for violating the big-bang-nucleosynthesis bound, contrary to the original string-gas scenario. In contrast, the GWB of the pre-big-bang scenario falls within the sensitivity window of both LISA and Einstein Telescope, where it takes the form of a single or a broken power law depending on the choice of parameters. The latter will be tightly constrained by both detectors.
Gravitationally produced dark matter and primordial black holes
Authors: Bertuzzo Enrico , Perez-Gonzalez Yuber F. , Salla Gabriel M. , Funchal Renata Zukanovich 
Published: September 2024

Abstract
We examine how the existence of a population of primordial black holes (PBHs) influences cosmological gravitational particle production (CGPP) for spin-0 and spin-1 particles.
In addition to the known effects of particle production and entropy dilution resulting from PBH evaporation, we find that the generation of dark matter (DM) through CGPP is profoundly influenced by a possible era of PBH matter domination.
This early matter dominated era results in an enhancement of the particle spectrum
from CGPP. Specifically, it amplifies the peak comoving momentum k
⋆ for spin-1 DM, while enhancing the plateau of the spectrum for minimally coupled spin-0 particles for low comoving momenta.
At the same time, the large entropy dilution may partially or completely compensate for the increase of the spectrum and strongly mitigates the DM abundance produced by CGPP. Our results show that, in the computation of the final abundance, CGPP and PBH evaporation cannot be disentangled, but the parameters of both sectors must be considered together to obtain the final result.
Furthermore, we explore the potential formation of PBHs from density fluctuations arising from CGPP and the associated challenges in such a scenario.
A possible late-time transition of M

B
inferred via neural networks
Authors: Mukherjee Purba , Dialektopoulos Konstantinos F. , Said Jackson Levi , Mifsud Jurgen 
Published: September 2024

Abstract
The strengthening of tensions in the cosmological parameters has led to reconsidering the fundamental aspects of standard cosmology. The tension in the Hubble constant can also be viewed as a tension between local and early Universe constraints on the absolute magnitude M

B
of Type Ia supernova. In this work, we reconsider the possibility of a variation of this parameter in a model-independent way. We employ neural networks to agnostically constrain the value of the absolute magnitude as well as assess the impact and statistical significance of a variation in M

B
with redshift from the Pantheon+ compilation, together with a thorough analysis of the neural network architecture. We find an indication for a possible transition redshift at the z ≈ 1 region.
A new diagnostic for the null test of dynamical dark energy in light of DESI 2024 and other BAO data
Authors: Dinda Bikash R. 
Published: September 2024

AbstractWe introduce a new diagnostic for the null tests of dynamical dark energy alongside two other combined equivalent diagnostics. These diagnostics are useful, especially when we include anisotropic baryon acoustic oscillation (BAO) data in an analysis, to quantify the deviations from the standard ΛCDM model. We also consider another diagnostic for isotropic BAO observations. These null tests are independent of any late-time dark energy model or parametrization. With these diagnostics, we study the evidence for dynamical dark energy in light of Dark Energy Spectroscopic Instrument (DESI) 2024 data combined with cosmic microwave background (CMB) observations of the Planck 2018 mission and localH0measurements. We find no strong evidence for dynamical dark energy. The exclusion of the individual deviations at the effective redshift 0.51 of the DESI 2024 data makes the evidence even weaker. We get nearly similar results for other non-DESI BAO data. Both for DESI 2024 and other non-DESI BAO data, the evidence is almost independent of early-time physics. The evidence corresponding to the SHOES value ofH0is higher than the corresponding tRGB value ofH0for all combinations of data, but still not strong enough to reject the flat ΛCDM model.
Helicity-changing decays of cosmological relic neutrinos
Authors: Huang Jihong , Zhou Shun 
Published: September 2024

AbstractIn this paper, we examine the possibility that massive neutrinos are unstable due to their invisible decaysνi→νj+ϕ, whereνiandνj(fori,j= 1, 2, 3) are any two of neutrino mass eigenstates with massesmi>miandϕis a massless Nambu-Goldstone boson, and explore the implications for the detection of cosmological relic neutrinos in the present Universe. First, we carry out a complete calculation of neutrino decay rates in the general case where the individual helicities of parent and daughter neutrinos are specified. Then, the invisible decays of cosmological relic neutrinos are studied and their impact on the capture rates on the beta-decaying nuclei (e.g.,νe+3H →3He +e-) is analyzed. The invisible decays of massive neutrinos could substantially change the capture rates in the PTOLEMY-like experiments when compared to the case of stable neutrinos. In particular, we find that the helicity-changing decays of Dirac neutrinos play an important role whereas those of Majorana neutrinos have no practical effects. However, if a substantial fraction of heavier neutrinos decay into the lightest one, the detection of relic neutrinos will require a much higher energy resolution and thus be even more challenging.