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Transfer of 200 mm GeSn wafers using bonded etch-back silicon-on-insulator process
No full textInternational audienceGeSn alloys exhibit significant potential for mid-infrared devices. The increase of Sn content and the application of tensile strain can convert such alloys into direct bandgap semiconductors. However, a virtual Ge buffer substrate and a grading of the tin concentration are generally required for the growth of high tin content GeSn layers. This growth approach leads to misfit dislocations in the vicinity of the optically active GeSn layer on top and to a degraded optical confinement. In this work, we demonstrate a CMOS-compatible transfer of 200 mm GeSn wafers with a 14–16 % tin content. A comparative study between germane and digermane precursor gases for GeSn growth is also conducted. The crystallinity and composition of as-grown and transferred GeSn layers are characterized using x-rays, Raman and photoluminescence spectroscopies, Atomic Force Microscopy and Transmission Electron Microscopy
Particle background characterization and prediction for the NUCLEUS reactor CENS experiment
No full textInternational audienceNUCLEUS is a cryogenic detection experiment which aims to measure Coherent Elastic Neutrino-Nucleus Scattering (CENS) and to search for new physics at the Chooz nuclear power plant in France. This article reports on the prediction of particle-induced backgrounds, especially focusing on the sub-keV energy range, which is a poorly known region where most of the CENS signal from reactor antineutrinos is expected. Together with measurements of the environmental background radiations at the experimental site, extensive Monte Carlo simulations based on the Geant4 package were run both to optimize the experimental setup for background reduction and to estimate the residual rates arising from different contributions such as cosmic ray-induced radiations, environmental gammas and material radioactivity. The NUCLEUS experimental setup is predicted to achieve a total rejection power of more than two orders of magnitude, leaving a residual background component which is strongly dominated by cosmic ray-induced neutrons. In the CENS signal region of interest between 10 and 100 eV, a total particle background rate of 250 dkgkeV is expected in the CaWO target detectors. This corresponds to a signal-to-background ratio 1, and therefore meets the required specifications in terms of particle background rejection for the detection of reactor antineutrinos through CENS
Spatiotemporal changes and drivers of net greenhouse gas emissions from major cropping systems in China during 1984–2018
No full textInternational audienc
Integrability and lattice discretizations of all Topological Defect Lines in minimal CFTs
No full textInternational audienceWe discuss in this paper the lattice discretizations of all topological defect lines (TDLs) for diagonal, minimal CFTs, using integrable restricted solid-on-solid (RSOS) models. For these CFTs, the TDLs can be labeled by the Kac labels. In the case of TDLs, lines that are exactly topological on the lattice can be obtained using the centralizer of the underlying Temperley-Lieb algebra, all the other lines become topological in the continuum limit only. Our general construction relies on insertions of rows/columns of faces with modified spectral parameters, and can therefore be studied using integrability techniques. We determine the regions of spectral parameters realizing the different TDLs, and in particular calculate analytically all the associated eigenvalues (and degeneracy factors). We also show how fusion of TDLs can be obtained from fusion hierarchies in the algebraic approach to the Bethe-ansatz. All our results are checked numerically in detail for several minimal CFTs
Capability of thermodesorption/pyrolysis DART FT-ICR MS to distinguish fluoropolymers and identify blend composition
No full textInternational audienceDirect analysis in real time (DART) was coupled with a thermal desorption/pyrolysis (TDPy) device for the analysis of fluoropolymers. The product ions were analyzed using a Fourier transform cyclotron resonance mass spectrometer (FT-ICR MS). Two different polyvinylidene fluoride (PVDF) samples were studied individually and in a 50/50 mixture. This study demonstrates the capability of TDPy DART FT-ICR MS to provide information on PVDF polymers, including the determination of end-groups and the detection of comonomers.The temperature program used enabled the desorption of the smallest oligomers (Mn ≈ 600 Da) below 400 °C, allowing for the identification of the end-groups, which ensured the differentiation of the PVDF. At temperatures above 400 °C, Cw Hx Fy- ions were predominantly formed as a result of the thermal cleavage of the PVDF backbone.Specific pyrolysis products observed for one PVDF sample suggested the presence of 4.6 mol% hexafluoropropylene (HFP), as determined by NMR measurements. The molar percentage of HFP was also determined by a new approach using TDPy DART MS. The analysis of a 50/50 PVDF blend revealed species from both polymers during the thermo-desorption and pyrolysis events, confirming the ability of the proposed methodology to determine the mol% of the HFP comonomer. This represents the first TDPy DART FT-ICR MS study of fluoropolymers. Applicable to non-soluble or poorly soluble polymers, the proposed methodology enables the identification of end-groups, suggests the possibility of distinguishing fluoropolymers, and identifies blend composition. Additionally, the molar percentage of comonomers can be defined for poly(VDF-co-HFP) copolymers.</div
Muon tracking in a LiquidO opaque scintillator detector
No full textInternational audienceLiquidO is an innovative radiation detector concept. The core idea is to exploit stochastic light confinement in a highly scattering medium to self-segment the detector volume. In this paper, we demonstrate event-by-event muon tracking in a LiquidO opaque scintillator detector prototype. The detector consists of a 30 mm cubic scintillator volume instrumented with 64 wavelength-shifting fibres arranged in an 88 grid with a 3.2 mm pitch and read out by silicon photomultipliers. A wax-based opaque scintillator with a scattering length of approximately 0.5 mm is used. The tracking performance of this LiquidO detector is characterised with cosmic-ray muons and the position resolution is demonstrated to be 450 m per row of fibres. These results highlight the potential of LiquidO opaque scintillator detectors to achieve fine spatial resolution, enabling precise particle tracking and imaging
Anomalous thermal broadening in the Shastry-Sutherland model and SrCuBO
No full text5 pages, 5 figuresInternational audienceIn the quantum magnet SrCu(BO), an anomalous thermal broadening of the triplon modes has been measured at relatively low temperatures compared to the triplon gap using both inelastic neutron scattering and Raman spectroscopy. Given how accurately a broad variety of physical phenomena inSrCu(BO) are captured by the spin Shastry-Sutherland model, it remains an open question whether the anomalous thermal broadening is also an intrinsic feature of this minimal model. However, few techniques are available for computing the finite-temperature dynamics of strongly interacting many-body systems. To address this problem, we have developed a broadly applicable numerical simulation method based on matrix-product states to simulate dynamical spectral functions at nonzero temperatures accurately, detailed in a companion paper [Phys. Rev. B 113, 024406 (2026)]. Using this technique, we demonstrate that the experimentally observed broadening is captured by the Shastry-Sutherland model. Perturbative calculations identify the origin of this phenomenon as singlet bound two-triplon states being thermally excited at an energy scale small compared to the gap to the single triplon excitations at the experimentally relevant model parameters
Search for Magnetic Monopoles with the Complete ANTARES Dataset
No full textInternational audienceThis study presents a novel search for magnetic monopoles using data collected over a 14 year period (2008-2022) by the ANTARES neutrino telescope. The interaction of magnetic monopoles with matter was modeled according to Kazama, Yang, and Goldhaber cross-section. Upper limits on the flux of magnetic monopoles are obtained for velocities both above and below the Cherenkov threshold. No events consistent with the passage of magnetic monopoles were detected, enabling the setting of an upper flux limit for relativistic magnetic monopoles of the order of
Global mapping of thioredoxin interacting proteins in<i>Neurospora crassa</i>
No full textThioredoxins (Trx) are essential thiol-oxidoreductases that regulate redox homeostasis by reducing oxidized cysteines in a wide range of target proteins. However, the Trx system and other redox regulation mechanisms remain poorly characterized in saprotrophic filamentous fungi. Here, we identified the components of theNeurospora crassaTrx system and uncovered potential redox-regulated proteins using Trx affinity chromatography. Genome search identified three Trx and a single thioredoxin reductase that we named TRX1, TRX2 TRX3 and TRR. Notably, TRX1 carries a C-terminal disordered extension of unknown function, conserved in two ascomycete taxa (LeotiomycetesandSordariomycetes). Using recombinant cysteine-to-serine mutants of each Trx, we performed affinity chromatography and identified 1,998 proteins - approximately 19% of theN. crassaproteome. To rank the putative Trx targets, we applied a fold enrichment metric, comparing protein abundance before and after affinity chromatography. The average fold enrichment was four, with values reaching up to 117 for the most enriched protein, a DEAD/DEAH box helicase. Among the top-enriched proteins, we identified homologs of known human and plant Trx targets, like peroxiredoxins, as well as 93 transcription factors and 38 kinases. Additional potential Trx targets encompass, ubiquitination-related enzymes, Fe-S cluster assembly proteins, phospholipases, exonucleases, and chitin synthases. Moreover, components of multiprotein complexes were co-purified, reflecting both direct Trx interactions and indirect co-association. Overall, this study provides a global map of potential redox regulated proteins and Trx targets inN. crassa, laying the ground for future investigations into redox signaling in filamentous fungi
Applying Gaussian Mixture Models to Track Reconstruction in Inelastic Scattering Experiments with Active Targets
No full textInternational audienceActive targets such as ACTAR TPC are well suited for studying giant resonances in unstable nuclei via inelastic scattering in inverse kinematics. A key challenge in such measurements is the detection of low-energy ejectiles emitted at small angles relative to the beam direction. Accurate reconstruction of these tracks is essential for disentangling different resonance modes. Probabilistic models such as the Gaussian Mixture Model (GMM) are particularly effective in capturing the complex covariance structures characteristic of the beam-recoil interface in narrow-angle events. In this work, we present a track reconstruction approach based on the GMM, specifically designed for inelastic scattering experiments with active targets. Special emphasis is placed on the treatment of low-energy tracks. The proposed method is demonstrated on simulated data of the reaction at an incident energy of ~MeV/nucleon, generated under conditions representative of the experiment carried out at GANIL for the same reaction