bluuebunny/crossref_metadata_2025_split huggingface dataset:
Charge–spin interconversion in nitrogen sputtered Pt via extrinsic spin Hall effect
Authors: Shashank Utkarsh , Kusaba Yu , Nakamura Junnosuke , Mathew Arun Jacob , Imai Koki , Senba Shinya , Asada Hironori , Fukuma Yasuhiro 
Published: April 2024

Abstract
We experimentally investigate the charge–spin interconversion by introducing a lighter impurity, namely nitrogen (N) into Pt by varying the nitrogen gas flow rate, Q from 0 to 20%, and studying the Onsager reciprocity of spin Hall effect (SHE) via complementary methods of spin-torque ferromagnetic resonance and spin-pumping inverse SHE measurements, respectively. We notice a reduction in the crystalline nature of Pt upon nitrogen incorporation. We observe the influence of extrinsic side-jump scattering induced SHE by measuring the spin Hall efficiency,

θ

SH

in a wide temperature range from 10 to 296 K. This work establishes the incorporation of N in Pt by using sputtering, to enhance the SHE via extrinsic scattering as well as to observe the reciprocal effects of charge–spin interconversion.
Anomalous Hall effect and magnetic transition in the kagome material YbMn6Sn6
Authors: Jiang Lei , Fan Feng-Ren , Chen Dong , Mu Qingge , Wang Yiyan , Yue Xiaoyu , Li Na , Sun Yan , Li Qiuju , Wu Dandan , Zhou Ying , Sun Xuefeng , Liang Hui 
Published: April 2024

Abstract
We investigate the magnetic and transport properties of a kagome magnet YbMn6Sn6. We have grown YbMn6Sn6 single crystals having a HfFe6Ge6 type structure with ordered Yb and Sn atoms, which is different from the distorted structure previously reported. The single crystal undergoes a ferromagnetic phase transition around 300 K and a ferrimagnetic transition at approximately 30 K, and the magnetic transition at low temperature may be correlated to the ordered Yb sublattice. Negative magnetoresistance has been observed at high temperatures, while the positive magnetoresistance appears at 5 K when the current is oriented out of kagome plane. We observe a large anisotropic anomalous Hall effect with the intrinsic Hall contribution of 141 Ω−1cm−1 for

σ

z
x

int

and 32 Ω−1cm−1 for

σ

x
y

int

, respectively. These values are similar to those in YMn6Sn6 with the same anisotropy. The magnetic transition and anomalous Hall behavior in YbMn6Sn6 highlights the influence of the ordered Yb atoms and rare earth elements on its magnetic and transport properties.
Recombination dynamics and manybody effect of excitons in large-area monolayer MoS2 capped with (111) NiO epitaxial layer
Authors: Mujeeb Faiha , Rana Gourab , Chakrabarti Poulab , Prasad Sahu Bhabani , Jeena Rupa , Datta Anindya , Dhar Subhabrata 
Published: April 2024

Abstract
CVD grown monolayer MoS2 films on c-sapphire substrates are vacuum annealed and capped with (111) NiO epitaxial films using pulsed laser deposition technique. Time, energy and polarization resolved optical techniques are used to understand the effect of capping on the excitonic properties of the monolayer MoS2. It has been observed that trion contribution in the photoluminescence (PL) spectra increases after the capping, suggesting an enhancement of electron concentration in the conduction band. This has been attributed to the capping driven reduction of physisorbed air molecules from the sulphur vacancy (

V

S

) sites. Note that the air molecules act as passivating agents for the

V

S

-donors. Low temperature polarization resolved PL spectroscopy and ultrafast pump and probe transient absorption spectroscopy (TAS) show an increase of the biexcitonic population in the system after the encapsulation. The TAS study further reveals longer lifetime for both A and B excitons in capped samples implying a reduction of non-radiative recombination rate of the excitons after the capping. It has also been observed that in the capped samples,

K

/

K

′

valleys are populated with trions under sufficiently high pump powers. This has been attributed to the lower non-radiative recombination rates of the high energy photoexcited carriers and the faster transfer of either electrons or holes from the high energy pockets to the

K

/

K

′

valleys. The study further reveals different many-body effects in excitons and trions.
Coherent potential approximation study of impurity effect on monolayer hexagonal boron phosphide
Authors: Xu Jinrong , Liu Wenjing , Jiang Xiucai , Huang Kai , Li Ping , Yu Jiangying , You Yuwei , Wang Ying , Zhang Yuzhong 
Published: April 2024

Abstract
Impurity doping is a necessary technology for the application of semiconductor materials in microelectronic devices. The quantification of doping effects is crucial for controlling the transport properties of semiconductors. Here, taking two-dimensional (2D) hexagonal boron phosphide semiconductor as an example, we employ coherent potential approximation method to investigate the electronic properties of 2D semiconductor materials at low doping concentrations, which cannot be exploited with conventional density function theory. The results demonstrate that the positive or negative impurity potential in 2D semiconductors determines whether it is p-type or n-type doping, while the impurity potential strength decides whether it is shallow-level or deep-level doping. Impurity concentration has important impacts on not only the intensity but also the broadening of impurity peak in band gap. Importantly, we provide the operating temperature range of hexagonal boron phosphide as a semiconductor device under different impurity concentrations and impurity potentials. The methodology of this study can be applied to other 2D semiconductors, which is of great significance for quantitative research on the application of 2D semiconductors for electronic devices.
Is Ba3In2O6 a high-Tc
superconductor?
Authors: Hensling F V E , Dahliah D , Smeaton M A , Shrestha B , Show V , Parzyck C T , Hennighausen C , Kotsonis G N , Rignanese G-M , Barone M R , Subedi I , Disa A S , Shen K M , Faeth B D , Bollinger A T , Božović I , Podraza N J , Kourkoutis L F , Hautier G , Schlom D G 
Published: April 2024

Abstract
It has been suggested that Ba3In2O6 might be a high-Tc
superconductor. Experimental investigation of the properties of Ba3In2O6 was long inhibited by its instability in air. Recently epitaxial Ba3In2O6 with a protective capping layer was demonstrated, which finally allows its electronic characterization. The optical bandgap of Ba3In2O6 is determined to be 2.99 eV in-the (001) plane and 2.83 eV along the c-axis direction by spectroscopic ellipsometry. First-principles calculations were carried out, yielding a result in good agreement with the experimental value. Various dopants were explored to induce (super-)conductivity in this otherwise insulating material. Neither A- nor B-site doping proved successful. The underlying reason is predominately the formation of oxygen interstitials as revealed by scanning transmission electron microscopy and first-principles calculations. Additional efforts to induce superconductivity were investigated, including surface alkali doping, optical pumping, and hydrogen reduction. To probe liquid-ion gating, Ba3In2O6 was successfully grown epitaxially on an epitaxial SrRuO3 bottom electrode. So far none of these efforts induced superconductivity in Ba3In2O6, leaving the answer to the initial question of whether Ba3In2O6 is a high-Tc
superconductor to be ‘no’ thus far.
A measurement method of in-bore projectile motion acceleration based on bottom pressure correction
Authors: Zhang Yongjian , Peng Peng , Liu Tiantian , Li Dahai , Di Changan 
Published: April 2024

Abstract
Due to factors such as high temperatures, elevated pressures, and severe high-frequency shocks in the bore, there is considerable noise interference in acceleration test signals. This makes it challenging to accurately measure projectile motion acceleration using existing methods. To address this issue, we propose an advanced measurement approach that uses bottom pressure correction. Our model suggests a significant correlation between projectile motion acceleration and thrust. By utilizing the correlations between bottom pressure and motion acceleration in both temporal and frequency domains, we can improve the accuracy of acceleration measurements. Based on these insights, we have developed a novel testing system that synchronously measures bottom pressure and acceleration, using bottom pressure as a corrective mechanism for the measured acceleration signals. Empirical results show that the maximum relative error in peak motion acceleration is only 4.86%, demonstrating the effectiveness of our proposed method.
Meeting the detector challenges for pre-clinical proton and ion computed tomography
Authors: Johnson Robert P 
Published: April 2024

Abstract
Six decades after its conception, proton computed tomography (pCT) and proton radiography have yet to be used in medical clinics. However, good progress has been made on relevant detector technologies in the past two decades, and a few prototype pCT systems now exist that approach the performance needed for a clinical device. The tracking and energy-measurement technologies in common use are described, as are the few pCT scanners that are in routine operation at this time. Most of these devices still look like detector R&D efforts as opposed to medical devices, are difficult to use, are at least a factor of five slower than desired for clinical use, and are too small to image many parts of the human body. Recommendations are made for what to consider when engineering a pre-clinical pCT scanner that is designed to meet clinical needs in terms of performance, cost, and ease of use.
An end-to-end multi-scale airway segmentation framework based on pulmonary CT image
Authors: Yuan Ye , Tan Wenjun , Xu Lisheng , Bao Nan , Zhu Quan , Wang Zhe , Wang Ruoyu 
Published: April 2024

AbstractObjective. Automatic and accurate airway segmentation is necessary for lung disease diagnosis. The complex tree-like structures leads to gaps in the different generations of the airway tree, and thus airway segmentation is also considered to be a multi-scale problem. In recent years, convolutional neural networks have facilitated the development of medical image segmentation. In particular, 2D CNNs and 3D CNNs can extract different scale features. Hence, we propose a two-stage and 2D + 3D framework for multi-scale airway tree segmentation.Approach. In stage 1, we use a 2D full airway SegNet(2D FA-SegNet) to segment the complete airway tree. Multi-scale atros spatial pyramid and Atros Residual Skip connection modules are inserted to extract different scales feature. We designed a hard sample selection strategy to increase the proportion of intrapulmonary airway samples in stage 2. 3D airway RefineNet (3D ARNet) as stage 2 takes the results of stage 1 asa prioriinformation. Spatial information extracted by 3D convolutional kernel compensates for the loss of in 2D FA-SegNet. Furthermore, we added false positive losses and false negative losses to improve the segmentation performance of airway branches within the lungs.Main results. We performed data enhancement on the publicly available dataset of ISICDM 2020 Challenge 3, and on which evaluated our method. Comprehensive experiments show that the proposed method has the highest dice similarity coefficient (DSC) of 0.931, and IoU of 0.871 for the whole airway tree and DSC of 0.699, and IoU of 0.543 for the intrapulmonary bronchi tree. In addition, 3D ARNet proposed in this paper cascaded with other state-of-the-art methods to increase detected tree length rate by up to 46.33% and detected tree branch rate by up to 42.97%.Significance. The quantitative and qualitative evaluation results show that our proposed method performs well in segmenting the airway at different scales.
GMAlignNet: multi-scale lightweight brain tumor image segmentation with enhanced semantic information consistency
Authors: Song Jianli , Lu Xiaoqi , Gu Yu 
Published: April 2024

Abstract
Although the U-shaped architecture, represented by UNet, has become a major network model for brain tumor segmentation, the repeated convolution and sampling operations can easily lead to the loss of crucial information. Additionally, directly fusing features from different levels without distinction can easily result in feature misalignment, affecting segmentation accuracy. On the other hand, traditional convolutional blocks used for feature extraction cannot capture the abundant multi-scale information present in brain tumor images. This paper proposes a multi-scale feature-aligned segmentation model called GMAlignNet that fully utilizes Ghost convolution to solve these problems. Ghost hierarchical decoupled fusion unit and Ghost hierarchical decoupled unit are used instead of standard convolutions in the encoding and decoding paths. This transformation replaces the holistic learning of volume structures by traditional convolutional blocks with multi-level learning on a specific view, facilitating the acquisition of abundant multi-scale contextual information through low-cost operations. Furthermore, a feature alignment unit is proposed that can utilize semantic information flow to guide the recovery of upsampled features. It performs pixel-level semantic information correction on misaligned features due to feature fusion. The proposed method is also employed to optimize three classic networks, namely DMFNet, HDCNet, and 3D UNet, demonstrating its effectiveness in automatic brain tumor segmentation. The proposed network model was applied to the BraTS 2018 dataset, and the results indicate that the proposed GMAlignNet achieved Dice coefficients of 81.65%, 90.07%, and 85.16% for enhancing tumor, whole tumor, and tumor core segmentation, respectively. Moreover, with only 0.29 M parameters and 26.88G FLOPs, it demonstrates better potential in terms of computational efficiency and possesses the advantages of lightweight. Extensive experiments on the BraTS 2018, BraTS 2019, and BraTS 2020 datasets suggest that the proposed model exhibits better potential in handling edge details and contour recognition.
Probabilistic U-Net model observer for the DDC method in CT scan protocol optimization
Authors: Stocker David , Sommer Christian , Gueng Sarah , Stäuble Jason , Özden Ismail , Griessinger Jennifer , Weyland Mathias S , Lutters Gerd , Scheidegger Stephan 
Published: April 2024

Abstract
Optimizing complex imaging procedures within Computed Tomography, considering both dose and image quality, presents significant challenges amidst rapid technological advancements and the adoption of machine learning (ML) methods. A crucial metric in this context is the Difference-Detailed Curve, which relies on human observer studies. However, these studies are labor-intensive and prone to both inter- and intra-observer variability. To tackle these issues, a ML-based model observer utilizing the U-Net architecture and a Bayesian methodology is proposed. In order to train a model observer unaffected by the spatial arrangement of low-contrast objects, the image preprocessing incorporates a Gaussian Process-based noise model. Additionally, gradient-weighted class activation mapping is utilized to gain insights into the model observer’s decision-making process. By training on data from a diverse group of observers, well-calibrated probabilistic predictions that quantify observer variability are achieved. Leveraging the principles of Beta regression, the Bayesian methodology is used to derive a model observer performance metric, effectively gauging the model observer’s strength in terms of an ‘effective number of observers’. Ultimately, this framework enables to predict the DDC distribution by applying thresholds to the inferred probabilities (Part of this work has been presented at: Stocker D, Sommer C, Gueng S, Stäuble J, Özden I, Griessinger J, Weyland M S, Lutters G, Scheidegger S (2023). Probabilistic U-Net Model Observer for the DDC Method in CT Scan Protocol Optimization. The 56th SSRMP Annual Meeting 2023, November 30. - December 1., 2023, Luzern, Switzerland).
TOPAS simulation of photoneutrons in radiotherapy: accuracy and speed with variance reduction
Authors: Ramos-Mendez J , Ortiz Catalan R , Schuemann J , Paganetti H , Faddegon B 
Published: April 2024

Abstract

Objective. We provide optimal particle split numbers for speeding up TOPAS Monte Carlo simulations of linear accelerator (linac) treatment heads while maintaining accuracy. In addition, we provide a new TOPAS physics module for simulating photoneutron production and transport. Approach. TOPAS simulation of a Siemens Oncor linac was used to determine the optimal number of splits for directional bremsstrahlung splitting as a function of the field size for 6 MV and 18 MV x-ray beams. The linac simulation was validated against published data of lateral dose profiles and percentage depth-dose curves (PDD) for the largest square field (40 cm side). In separate simulations, neutron particle split and the custom TOPAS physics module was used to generate and transport photoneutrons, called ‘TsPhotoNeutron’. Verification of accuracy was performed by comparing simulations with published measurements of: (1) neutron yields as a function of beam energy for thick targets of Al, Cu, Ta, W, Pb and concrete; and (2) photoneutron energy spectrum at 40 cm laterally from the isocenter of the Oncor linac from an 18 MV beam with closed jaws and MLC. Main results. The optimal number of splits obtained for directional bremsstrahlung splitting enhanced the computational efficiency by two orders of magnitude. The efficiency decreased with increasing beam energy and field size. Calculated lateral profiles in the central region agreed within 1 mm/2% from measured data, PDD curves within 1 mm/1%. For the TOPAS physics module, at a split number of 146, the efficiency of computing photoneutron yields was enhanced by a factor of 27.6, whereas it improved the accuracy over existing Geant4 physics modules. Significance. This work provides simulation parameters and a new TOPAS physics module to improve the efficiency and accuracy of TOPAS simulations that involve photonuclear processes occurring in high-Z materials found in linac components, patient devices, and treatment rooms, as well as to explore new therapeutic modalities such as very-high energy electron therapy.
Avalanche statistics of fluctuation-induced fluxes from the SLPM and the W7-AS stellarator
Authors: Mier J A , Blanco J , Sánchez R , Castellanos O F , Newman D E , Anabitarte E , López J M 
Published: April 2024

Abstract
Measurements of fluctuating floating potentials and ion saturation currents at different radial locations in the Santander Linear Plasma Machine (Castellanos et al 2005 Plasma Phys. Control. Fusion
47 2067) and at the edge of the W7-AS stellarator by means of radially movable Langmuir probes allow to infer the corresponding fluctuation-induced radial flux temporal series. Avalanche-like transport events are identified in the time series and statistically characterized in terms of avalanche size/duration/quiet-time distributions and size-duration scaling relations. Transport is diffusive in the inner and intermediate radial region of the SLPM

r
<

r
tr

≈
2.6

cm, undergoing a transition at

r
tr

, becoming non-diffusive in the outermost region of the device,

r
>

r
tr

. The results obtained at the edge of the W7-AS stellarator are similar to those found in SLPM for

r
>

r
tr

, i.e. consistent with what would be expected for scale-free, self-similar plasma transport dynamics near a critical state.
Study of the photoluminescence properties of GaN irradiated with low fluence Ta ions
Authors: Wei Wanting , Zhao Guijuan , Liu Jiande , Wang Xingliang , Liu Guipeng 
Published: April 2024

Abstract
The irradiation influences the properties of GaN. We studied the irradiation of n-type, p-type, and i-type GaN with 2.896 GeV Ta ions, with experimental irradiation fluence of 3 × 108, 3 × 109, and 2 × 1010 cm−2, respectively. Low fluence ion irradiation of GaN enhances the luminescence performance of the samples and releases stress between GaN and the sapphire substrate. We demonstrate by characterizing GaN that this is due to the displacement of Ga or N atoms repairing the defects caused by the entry of irradiated ions, thus enhancing the performance of GaN. This provides a reference for low fluence irradiation of GaN.
A negative capacitance field effect transistor with a modified gate stack and drain-side cavity for label-free biosensing
Authors: Kansal Harshit , Medury Aditya Sankar 
Published: April 2024

Abstract
Dielectrically modulated (DM) negative capacitance field effect transistor (NCFET)-based label-free biosensors have emerged as promising devices for accurate detection of various biomolecules, where the sensitivity of DM architectures strongly depends on the sensing mechanism as well as on the size of the nanocavity. Therefore, to achieve higher sensitivity along with reduced fabrication complexity, we propose to utilize a pre-existing drain-side spacer region as a nanocavity, in a fully depleted silicon-on-insulator-based NCFET architecture. The ferroelectric (FE) layer in the metal-ferroelectric-insulator-semiconductor configuration meaningfully alters the impact of the drain’s electric field on the source-side electrostatics, which results in higher sensitivity. Having quantified the sensitivity of an FE-dielectric (FE-DE) gate-stack-based NCFET biosensor, we now propose to include a paraelectric (PE) layer between the FE and DE materials, thus modifying the gate stack from FE-DE to FE-PE-DE with an equivalent negative capacitance seen from both stacks; here, a remarkable improvement is seen in the FE-PE-DE gate-stack-based NCFET, with nearly identical linearity performance, as seen from the high Pearson’s coefficient value (

r
2

⩾

0.9). Therefore, to illustrate the efficacy of the proposed sensing mechanism and the modified gate stack (FE-PE-DE), DE constant (

k

Bio

) values in the range of

k

Bio

= 4.5 to

k

Bio

= 75.99 are considered. Finally, the effect of scaling the channel length (

L

g

) on the sensitivity of the FE-PE-DE NCFET device is shown, and a high value, particularly at lower permittivity, demonstrates the versatility and wide applicability of the proposed NCFET biosensor.
Manipulating the dipolar interactions and cooperative effects in confined geometries
Authors: Alaeian Hadiseh , Skljarow Artur , Scheel Stefan , Pfau Tilman , Löw Robert 
Published: April 2024

Abstract
To facilitate the transition of quantum effects from the controlled laboratory environment to practical real-world applications, there is a pressing need for scalable platforms. One promising strategy involves integrating thermal vapors with nanostructures designed to manipulate atomic interactions. In this tutorial, we aim to gain deeper insights into this by examining the behavior of thermal vapors that are confined within nanocavities or waveguides and exposed to near-resonant light. We explore the interactions between atoms in confined dense thermal vapors. Our investigation reveals deviations from the predictions of continuous electrodynamics models, including density-dependent line shifts and broadening effects. In particular, our results demonstrate that by carefully controlling the saturation of single atoms and the interactions among multiple atoms using nanostructures, along with controlling the geometry of the atomic cloud, it becomes possible to manipulate the effective optical nonlinearity of the entire atomic ensemble. This capability renders the hybrid thermal atom-nanophotonic platform a distinctive and valuable one for manipulating the collective effect and achieving substantial optical nonlinearities.