cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Probing the low-mass end of the companion mass function for O-type stars
Creators: name: Reggiani, M.
name: Rainot, A.
name: Sana, H.
name: Almeida, L. A.
name: Caballero-Nieves, S.
name: Kratter, K.
name: Lacour, S.
name: LeBouquin, J. -B.
name: Zinnecker, H.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: Almost all massive stars are part of a binary system. Given the wide range of separations at which these companions are found, several observational techniques have been adopted to characterize them, but contrasts greater than 4 in the H-band have never been reached between 0".1 and 1". We used VLT/SPHERE to observe simultaneously with the IRDIS and IFS sub-systems 18 O-type stars within 6 kpc and ages between 1-5 Myrs to probe the existence of stellar companions in the angular separation range from 0".15 to 6" down to very low mass ratios. The IFS YJH- band observations have allowed us to probe the presence of sub-solar companions in a 1".7x1".7 field-of-view down to magnitude limits of deltaH=10 at 0".4. In the wider 12"x12" IRDIS field-of-view, we reached contrasts of deltaK=12 at 1", enabling us to look for even fainter companions. This paper presents five newly discovered intermediate (<1") separation companions, three of which are smaller than 0.2M_sun. If confirmed by future analyses of proper motions, these new detections represent the lowest-mass companions ever found around O-type stars. Assuming that all sources detected within 1" are physically bound, the observed fraction of companions for O-type stars between 0".15 and 0".9 is 0.39+/-0.15, whereas it increases to 1.6+/-0.3 in the separation range from 0".9 to 6". These findings clearly support the notion that massive stars form almost exclusively in multiple systems, and that larger AO-assisted coronagraphic surveys are crucial in placing constraints on the multiplicity properties of massive star companions in regions of the parameter space that have previously gone unexplored, and demonstrate that the companion mass function is populated down to the lowest stellar masses.
description: Accepted for publication in Astronomy & Astrophysics. 14 pages, 12 figures
Model-Independent Determination of Isotopic Cross Sections per Fission for Reactor Antineutrinos
Creators: name: Li, Yu-Feng
name: Xin, Zhao
Publisher: name: arXiv
Year: 2021
Subjects: subject: Nuclear Theory (nucl-th)
subject: High Energy Physics - Experiment (hep-ex)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: Model-independent reactor isotopic cross sections per fission are determined by global fits of the reactor antineutrino data from High-Enriched Uranium (HEU) reactor rates, Low-Enriched Uranium (LEU) reactor rates, and reactor fuel evolution data. Taking account of the implicit quasi-linear relationship between the fission fractions of $^{239}\rm{Pu}$ and $^{241}\rm{Pu}$ in the LEU reactor data, the Inverse-Beta-Decay (IBD) yields and their correlations of the fissionable isotopes $^{235}\rm{U}$, $^{238}\rm{U}$, and Pu's are obtained. The data-driven isotopic IBD yields provide an anomaly-free model for the reactor isotopic cross sections per fission, where better than 1\% accuracy of the expected reactor IBD yields can be achieved for future experiments.
description: 11 pages, 4 figures. With more discussions and references added, accepted for publication at Physical Review D
BuRNN: Buffer Region Neural Network Approach for Polarizable-Embedding Neural Network / Molecular Mechanics Simulations
Creators: name: Lier, Bettina
name: Poliak, Peter
name: Marquetand, Philipp
name: Westermayr, Julia
name: Oostenbrink, Chris
Publisher: name: arXiv
Year: 2021
Subjects: subject: Chemical Physics (physics.chem-ph)
subject: FOS: Physical sciences

description: Hybrid quantum mechanics/molecular mechanics (QM/MM) simulations have advanced the field of computational chemistry tremendously. However, they require the partitioning of a system into two different regions that are treated at different levels of theory, which can cause artefacts at the interface. Furthermore, they are still limited by high computational costs of quantum chemical calculations. In this work, we develop BuRNN, an alternative approach to existing QM/MM schemes, which introduces a buffer region that experiences full electronic polarization by the inner QM region to minimize artefacts. The interactions between the QM and the buffer region are described by deep neural networks (NNs), which leads to high computational efficiency of this hybrid NN/MM scheme while retaining quantum chemical accuracy. We demonstrate the BuRNN approach by performing NN/MM simulations of the hexa-aqua iron complex.
description: 37 pages, 9 figures
Structural and geomorphological map of the Passo San Marco – Pizzo di Trona area (Western Orobic Alps, Southern Alps, Italy)
Creators: name: Ghiselli, Alice
name: Zucali, Michele
name: Bini, Alfredo
Publisher: name: Taylor & Francis
Year: 2015
Subjects: subject: Biological Sciences
subject: Astronomy, Astrophysics, Space Science
subject: Ecology
subject: FOS: Biological sciences
subject: Earth and Environmental Sciences
subject: Biochemistry
subject: Biophysics

description: We present a structural and geomorphological map of the Passo San Marco – Pizzo di Trona area (Northwestern Orobic Alps). This area was studied in order to make a contribution to the mapping and interpretation of the landforms and the mesoscale structures in the basement and sedimentary cover. The aim of this study is to provide a useful insight for a better understanding of the geological and geomorphological evolution of the Orobic belt during the Alpine orogenesis. The original geological survey was carried out at a 1:5000 scale while the presented map is at a 1:8000 scale. In particular, a detailed structural survey of brittle and ductile structures was carried out. The structural analysis has led to the identification of six phases of deformation: three pre-Alpine and three Alpine. During these deformation phases, ductile (folds and foliations) and brittle (faults, cataclasites and pseudotachylites) structures developed both in the Variscan basement and in the Permo-Triassic sedimentary cover.
Neural Echo State Network using oscillations of gas bubbles in water
Creators: name: Maksymov, Ivan S.
name: Pototsky, Andrey
name: Suslov, Sergey A.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Fluid Dynamics (physics.flu-dyn)
subject: Emerging Technologies (cs.ET)
subject: Machine Learning (cs.LG)
subject: Neural and Evolutionary Computing (cs.NE)
subject: Dynamical Systems (math.DS)
subject: Chaotic Dynamics (nlin.CD)
subject: FOS: Physical sciences
subject: FOS: Computer and information sciences
subject: FOS: Mathematics

description: In the framework of physical reservoir computing (RC), machine learning algorithms designed for digital computers are executed using analog computer-like nonlinear physical systems that can provide energy-efficient computational power for predicting time-dependent quantities that can be found using nonlinear differential equations. We suggest a bubble-based RC (BRC) system that combines the nonlinearity of an acoustic response of a cluster of oscillating gas bubbles in water with a standard Echo State Network (ESN) algorithm that is well-suited to forecast chaotic time series. We confirm the plausibility of the BRC system by numerically demonstrating its ability to forecast certain chaotic time series similarly to or even more accurately than ESN.
description: 5 pages, 3 figures
Fast determination of Ziziphora tenuior L. essential oil by inorganic–organic hybrid material based on ZnO nanoparticles anchored to a composite made from polythiophene and hexagonally ordered silica
Creators: name: Piryaei, Marzieh
name: Abolghasemi, Mir Mahdi
name: Nazemiyeh, Hossein
Publisher: name: Taylor & Francis
Year: 2015
Subjects: subject: Inorganic Chemistry
subject: FOS: Chemical sciences
subject: Biological Sciences
subject: Ecology
subject: FOS: Biological sciences
subject: Chemistry
subject: Earth and Environmental Sciences
subject: Evolutionary Biology
subject: Biotechnology
subject: Molecular Biology
subject: Medicine
subject: Engineering

description: In this paper, for the first time, an inorganic–organic hybrid material based on ZnO nanoparticles was anchored to a composite made from polythiophene and hexagonally ordered silica (ZnO/PT/SBA-15) for use in solid-phase fibre microextraction (SPME) of medicinal plants. A homemade SPME apparatus was used for the extraction of volatile components of Ziziphora tenuior L. A simplex method was used for optimisation of five different parameters affecting the efficiency of the extraction. The main constituents extracted by ZnO/PT/SBA-15 and PDMS fibres and hydrodistillation (HD) methods, respectively, included pulegone (51.25%, 53.64% and 56.68%), limonene (6.73%, 6.58% and 8.3%), caryophyllene oxide (5.33%, 4.31% and 4.53%) and 1,8-cineole (4.21%, 3.31% and 3.18%). In comparison with the HD method, the proposed technique could equally monitor almost all the components of the sample, in an easier way, in a shorter time and requiring a much lower amount of the sample.
Sub-ns intrinsic response time of PbS nanocrystal IR-photodetectors
Creators: name: Maier, Andre
name: Strauß, Fabian
name: Kohlschreiber, Pia
name: Schedel, Christine
name: Braun, Kai
name: Scheele, Marcus
Publisher: name: arXiv
Year: 2021
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: Colloidal nanocrystals (NCs), especially lead sulfide NCs, are promising candidates for solution-processed next-generation photodetectors with high-speed operation frequencies. However, the intrinsic response time of PbS-NC photodetectors, which is the material-specific physical limit, is still elusive, as the reported response times are typically limited by the device geometry. Here, we use the two-pulse coincidence photoresponse technique to identify the intrinsic response time of 1,2-ethanedithiol-functionalized PbS-NC photodetectors after fs-pulsed 1560 nm excitation. We obtain an intrinsic response time of ~1 ns, indicating an intrinsic bandwidth of ~0.55 GHz as the material-specific limit. Examination of the dependence on laser power, gating, bias, temperature, channel length and environmental conditions suggest that Auger recombination, assisted by NC-surface defects, is the dominant mechanism. Accordingly, the intrinsic response time might further be tuned by specifically controlling the ligand coverage and trap states. Thus, PbS-NC photodetectors are feasible for gigahertz optical communication in the third telecommunication window.
description: 43 pages, 14 figures
Challenges to magnetic doping of thin films of the Dirac semimetal Cd$_3$As$_2$
Creators: name: Xiao, Run
name: Held, Jacob T
name: Rable, Jeffrey
name: Ghosh, Supriya
name: Wang, Ke
name: Mkhoyan, K. Andre
name: Samarth, Nitin
Publisher: name: arXiv
Year: 2021
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: Magnetic doping of topological quantum materials provides an attractive route for studying the effects of time-reversal symmetry breaking. Thus motivated, we explore the introduction of the transition metal Mn into thin films of the Dirac semimetal Cd3As2 during growth by molecular beam epitaxy. Scanning transmission electron microscopy measurements show the formation of a Mn-rich phase at the top surface of Mn-doped Cd3As2 thin films grown using both uniform doping and delta doping. This suggests that Mn acts as a surfactant during epitaxial growth of Cd3As2, resulting in phase separation. Magnetometry measurements of such samples indicate a ferromagnetic phase with out-of-plane magnetic anisotropy. Electrical magneto-transport measurements of these films as a function of temperature, magnetic field, and chemical potential reveal a lower carrier density and higher electron mobility compared to pristine Cd3As2 films grown under similar conditions. This suggests that the surfactant effect might also serve to getter impurities. We observe robust quantum transport (Shubnikov-de Haas oscillations and an incipient integer quantum Hall effect) in very thin (7 nm) Cd3As2 films despite being in direct contact with a structurally disordered surface ferromagnetic overlayer.
Radiative (anti)neutrino energy spectra from muon, pion, and kaon decays
Creators: name: Tomalak, Oleksandr
Publisher: name: arXiv
Year: 2021
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: High Energy Physics - Experiment (hep-ex)
subject: Nuclear Experiment (nucl-ex)
subject: Nuclear Theory (nucl-th)
subject: FOS: Physical sciences

description: To describe low-energy (anti)neutrino fluxes in modern coherent elastic neutrino-nucleus scattering experiments as well as high-energy fluxes in precision-frontier projects such as the Enhanced NeUtrino BEams from kaon Tagging (ENUBET) and the Neutrinos from STORed Muons (nuSTORM), we evaluate (anti)neutrino energy spectra from radiative muon ($μ^- \to e^- \barν_e ν_μ(γ),~μ^+ \to e^+ ν_e \barν_μ(γ)$), pion $π_{\ell 2}$ ($π^- \to μ^- \barν_μ(γ),~π^+ \to μ^+ ν_μ(γ)$), and kaon $K_{\ell 2}$ ($K^- \to μ^- \barν_μ(γ),~K^+ \to μ^+ ν_μ(γ)$) decays. We compare detailed $\mathrm{O} \left( α\right)$ distributions to the well-known tree-level results, investigate electron-mass corrections and provide energy spectra in analytical form. Radiative corrections introduce continuous and divergent spectral components near the endpoint, on top of the monochromatic tree-level meson-decay spectra, which can change the flux-averaged cross section at $6\times 10^{-5}$ level for the scattering on $^{40}\mathrm{Ar}$ nucleus with (anti)neutrinos from the pion decay at rest. Radiative effects modify the expected (anti)neutrino fluxes from the muon decay around the peak region by $3-4$ permille, which is a precision goal for next-generation artificial neutrino sources.
description: 14 pages, 2 figures. v2: journal version; minor corrections
Shearlet-based regularization in statistical inverse learning with an application to X-ray tomography
Creators: name: Bubba, Tatiana A.
name: Ratti, Luca
Publisher: name: arXiv
Year: 2021
Subjects: subject: Statistics Theory (math.ST)
subject: FOS: Mathematics

description: Statistical inverse learning theory, a field that lies at the intersection of inverse problems and statistical learning, has lately gained more and more attention. In an effort to steer this interplay more towards the variational regularization framework, convergence rates have recently been proved for a class of convex, $p$-homogeneous regularizers with $p \in (1,2]$, in the symmetric Bregman distance. Following this path, we take a further step towards the study of sparsity-promoting regularization and extend the aforementioned convergence rates to work with $\ell^p$-norm regularization, with $p \in (1,2)$, for a special class of non-tight Banach frames, called shearlets, and possibly constrained to some convex set. The $p = 1$ case is approached as the limit case $(1,2) \ni p \rightarrow 1$, by complementing numerical evidence with a (partial) theoretical analysis, based on arguments from $Γ$-convergence theory. We numerically demonstrate our theoretical results in the context of X-ray tomography, under random sampling of the imaging angles, using both simulated and measured data.
Control of site occupancy by variation of the Zn and Al content in NiZnAl ferrite epitaxial films with low magnetic damping
Creators: name: Lumetzberger, Julia
name: Ney, Verena
name: Zhakarova, Anna
name: Primetzhofer, Daniel
name: Lenz, Kilian
name: Ney, Andreas
Publisher: name: arXiv
Year: 2021
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: The structural and magnetic properties of Zn/Al doped nickel ferrite thin films can be adjusted by changing the Zn and Al content. The films are epitaxially grown by reactive magnetron sputtering using a triple cluster system to sputter simultaneously from three different targets. Upon the variation of the Zn content the films remain fully strained with similar structural properties, while the magnetic properties are strongly affected. The saturation magnetization and coercivity as well as resonance position and linewidth from ferromagnetic resonance (FMR) measurements are altered depending on the Zn content in the material. The reason for these changes can be elucidated by investigation of the x-ray magnetic circular dichroism spectra to gain site and valence specific information with elemental specificity. Additionally, from a detailed investigation by broadband FMR a minimum in g-factor and linewidth could be found as a function of film thickness. Furthermore, the results from a variation of the Al content using the same set of measurement techniques is given. Other than for Zn, the variation of Al affects the strain and even more pronounced changes to the magnetic properties are apparent.
description: 13 pages, 7 figures
Of cold ice, warm ice and water: thermodynamics of ice sheets and glaciers
Creators: name: Greve, Ralf
Publisher: name: Zenodo
Year: 2021
Subjects: Ice sheet
Glacier
Thermodynamics
Temperature
Water content
Polythermal ice
Model
Modelling

description: IGS Global Seminar, 13 October 2021, 20:00 UTC

Ralf Greve, Institute of Low Temperature Science, Hokkaido University, Japan

"Of cold ice, warm ice and water: thermodynamics of ice sheets and glaciers"

• Greve_Thermodynamics_IGS_2021.pdf: PDF version without animations• Greve_Thermodynamics_IGS_2021.ppsx: PowerPoint show with all animations
Pressure-induced structural transformation of clathrate Ge$_{136}$ via an ultrafast recrystallization of an amorphous intermediate
Creators: name: Ryník, Marián
name: Leoni, Stefano
name: Martoňák, Roman
Publisher: name: arXiv
Year: 2021
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: Disordered Systems and Neural Networks (cond-mat.dis-nn)
subject: FOS: Physical sciences

description: We study the pressure-induced structural transformation of Ge$_{136}$ clathrate by ab initio molecular dynamics and metadynamics. The system under pressure first undergoes amorphization followed by an ultrafast recrystallization to the $β$-tin structure on the time scale of 30 ps. The initial pressure-induced amorphization of clathrate is triggered by high pressure while the subsequent fast recrystallization to $β$-tin is driven by low temperature. Interestingly, the amorphous intermediate is still diffusive even at room temperature, in spite of very strong undercooling, making the ultrafast recrystallization possible. The system provides an explicit example of structural transformation between two crystalline phases proceeding via non-crystalline intermediate. Upon fast decompression of the amorphous structure with incipient crystalline order the recrystallization is blocked and the system instead proceeds to the tetrahedral LDA amorphous phase.
description: 5 pages, 5 figures, Supplementary Material
Gravitational shine of dark domain walls
Creators: name: Babichev, E.
name: Gorbunov, D.
name: Ramazanov, S.
name: Vikman, A.
Publisher: name: arXiv
Year: 2021
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: Cosmic domain walls are harmless, provided that their tension decreases with expansion of the Universe. This setup can be realized, if the scale of spontaneous symmetry breaking is induced dynamically through the interaction with hot primordial plasma. In that case, the domain wall tension can attain large values in the early Universe without any conflict with observations. Owing to the large initial tension, these topological defects may serve as a powerful source of gravitational waves. We make a preliminary estimate of the gravitational wave spectrum and argue that it is distinct from the spectrum produced by other sources, in particular by domain walls of a constant tension. The resulting gravitational wave signal is in the range accessible by Einstein Telescope, DECIGO, TianQin, LISA, IPTA, or SKA, if the field constituting the domain walls is very feebly coupled with hot primordial plasma and has tiny self-interactions. In particular, one can consider this field for the role of Dark Matter. We discuss various Dark Matter production mechanisms and properties of the emitted gravitational waves associated with them. We find that the conventional freeze-out and freeze-in mechanisms lead to large and perhaps unobservable frequency of gravitational waves. However, the Dark Matter production is also possible at the second order phase transition leading to the domain wall formation or at the inverse phase transition, when the domain walls get dissolved eventually. In both cases, there is essentially no lower bound on the frequency of emitted gravitational waves.
description: 38 pages, 5 figures; matches journal version
Visible Out-of-plane Polarized Luminescence and Electronic Resonance from Black Phosphorus
Creators: name: Schué, L.
name: Goudreault, F. A.
name: Righi, A.
name: Resende, G. C.
name: Lefebvre, V.
name: Godbout, E.
name: Pimenta, M. A.
name: Côté, M.
name: Francoeur, S.
name: Martel, R.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: Black Phosphorus (BP) is unique among layered materials owing to its homonuclear lattice and strong structural anisotropy. While recent investigations on few layers BP have extensively explored the in-plane (a,c) anisotropy, much less attention has been given to the out-of-plane direction (b). Here, the optical response from bulk BP is probed using polarization-resolved photoluminescence (PL), photoluminescence excitation (PLE) and resonant Raman scattering along the zigzag, out-of-plane, and armchair directions. PL reveals an unexpected b-polarized emission occurring in the visible at 1.75 eV, far above the fundamental gap (0.3 eV). PLE indicates that this emission is generated through b-polarized excitation at 2.3 eV. The same electronic resonance is observed in resonant Raman scans, where the scattering efficiency of both Ag phonon modes is enhanced. These experimental results are fully consistent with DFT calculations of the permittivity tensor elements and demonstrate the remarkable extent to which the anisotropy influences the optical properties and carrier dynamics in black phosphorus.
title: Programme européen Horizon 2020
Publisher: name: EHESS
Year: 2015

description:   Le programme Horizon 2020 regroupe les financements de l'Union   Européenne en matière de recherche et d'innovation pour la période   2014-2020. Doté de 79 milliards d’euros, il s'articule autour de trois   grandes priorités :           - l'excellence scientifique : financement de   projets de recherche, soutien à la mobilité des chercheurs et à la   construction de réseaux européens pour la formation doctorale, soutien   au développement d’infrastructures de recherche d’excellence ; - la primauté industrielle ; - les grands défis sociétaux dont le défi 6 «   L'Europe dans un monde en évolution : sociétés inclusives, innovantes et   réflexives ».     La recherche dans le domaine des sciences humaines   et sociales est pleinement intégrée à chacune des trois priorités.   Au-delà du pilier 1 – « Excellence scientifique » - qui repose sur
Activity-guided investigation of Carissa carandas (L.) roots for anti-inflammatory constituents
Creators: name: Sindhuja Galipalli
name: Patel, Neeraj K.
name: K. Prasanna
name: Bhutani, Kamlesh K.
Publisher: name: Taylor & Francis
Year: 2015
Subjects: subject: Biological Sciences
subject: Immunology
subject: FOS: Clinical medicine
subject: Ecology
subject: FOS: Biological sciences
subject: Chemistry
subject: Earth and Environmental Sciences
subject: Pharmacology
subject: Microbiology
subject: Engineering
subject: Biochemistry

description: The present study was structured to investigate the anti-inflammatory potential of the extracts, fractions and compounds isolated from Carissa carandas (L.) roots. Bioassay guided fractionation of methanol extract based on inhibitory potential towards proinflammatory mediators (TNF-α, IL-1β and nitric oxide (NO)) led to the identification of stigmasterol (1), lupeol (2), oleanolic acid (3), carissone (4) and scopoletin (5) as potential anti-inflammatory agents. Carissone (4) (IC50 = 20.1 ± 2.69 μg/mL) and scopoletin (5) (IC50 = 24.6 ± 1.36 μg/mL) exhibited significant inhibition of NO production comparable to specific NO inhibitor (L-NAME; IC50 = 19.82 ± 1.64 μg/mL) without affecting the cell viability. Also, 4 and 5 at a concentration of 30 μM were found to inhibit 41.88–53.44% of TNF-α and IL-1β. To the best of our knowledge, this is the first report displaying the anti-inflammatory effects of C. carandas (L.) roots, partially mediated by inhibition of TNF-α, IL-1β and NO.
Local random vector model for semiclassical fractal structure of chaotic resonance states
Creators: name: Clauß, Konstantin
name: Ketzmerick, Roland
Publisher: name: arXiv
Year: 2021
Subjects: subject: Chaotic Dynamics (nlin.CD)
subject: FOS: Physical sciences

description: The semiclassical structure of resonance states of classically chaotic scattering systems with partial escape is investigated. We introduce a local randomization on phase space for the baker map with escape, which separates the smallest multifractal scale from the scale of the Planck cell. This allows for deriving a semiclassical description of resonance states based on a local random vector model and conditional invariance. We numerically demonstrate that the resulting classical measures perfectly describe resonance states of all decay rates $γ$ for the randomized baker map. By decreasing the scale of randomization these results are compared to the deterministic baker map with partial escape. This gives the best available description of its resonance states. Quantitative differences indicate that a semiclassical description for deterministic chaotic systems must take into account that the multifractal structures persist down to the Planck scale.
Curvature control of the superconducting proximity effect in diffusive ferromagnetic nanowires
Creators: name: Salamone, Tancredi
name: Hugdal, Henning G.
name: Amundsen, Morten
name: Jacobsen, Sol H.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Superconductivity (cond-mat.supr-con)
subject: FOS: Physical sciences

description: Coupling a conventional s-wave superconductor to a ferromagnet allows, via the proximity effect, to generate superconducting triplet correlations. This feature can be employed to achieve a superconducting triplet spin-valve effect in superconductor-ferromagnet (SF) hybrid structures, for example by switching the magnetizations of the ferromagnets between parallel and antiparallel configurations in F1SF2 and SF1F2 trilayers, or in SF bilayers with both Rashba and Dresselhaus SOC. It was recently reported that geometric curvature can control the generation of long ranged triplets. We use this property to show that the superconducting critical temperature of an SF hybrid nanowire can be tuned by varying the curvature of the ferromagnetic side alone, with no need of another ferromagnet or SOC. We show that the variation of the critical temperature as a function of the curvature can be exploited to obtain a robust, curvature-controlled, superconducting triplet spin-valve effect. Furthermore, we perform an analysis with the inclusion of spin-orbit coupling and explain how it modifies the spin-valve effect both quantitatively and qualitatively.
description: 13 pages, 7 figures
Electrical Image Potential and Solvation Energies for an Ion in a Pore in a Metallic Electrode or in a Nanotube
Creators: name: Sokoloff, Jeffrey B
Publisher: name: arXiv
Year: 2021
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: Electrical image potentials can be important in small spaces, such as nanoscale pores in porous electrodes, which are used in capacitive desalination and in supercapacitors. It will be shown here that inside pores in porous metallic materials the image potentials can be considerably larger than near flat walls, as a result of the fact that the dielectric constant for an electric field perpendicular to a wall is much smaller than the bulk dielectric constant of water. Calculations will be presented for the image potential in spherical and cylindrically shaped pores. The calculations for cylindrical pores can also be applied to nanotubes. It was believed for a long time, on the basis of molecular dynamics simulations, that in order to push a salt solution through a small radius nanotube, work must be done against the solvation energy of the ions, which is larger inside a narrow nanotube than it is in the bulk. The relatively large image charge potential energy in narrow nanotubes, however, tends to oppose this increase in the solvation energy. The degree to which the image potential facilitates the flow of the salt ions into nanotubes will be discussed.
description: 21 pages, 3 figues
Collage Manifesto
Creators: name: Supreme, Point
Publisher: name: piano b. Arti e culture visive
Year: 2020
Subjects: Relationships; difference; lists; compression; displacement

description: Collage mentality pervades our work. We are interested in spaces of contradiction, unexpected associations and disruptions of meaning. We aim to transform reality with the minimum means. Collage use elements borrowed from reality, then employ them against it, aiming to attack everyday banalities, habits and formalities. These elements are brought together in a semiotic collision, undermining the role of consciousness, subjectivity and all questions of style. Architecture tries to remain archetypical, to not belong to any specific period or style. Collage as a technique facilitates the synthesis of oppositions in the built work; in essence, it originates from the power of the readymade. It aims at the uncanny connotations and subversive power that contradictory elements can create together. Influences like Warhol, Man Ray, Cadavre Exquis, Tarantino, Koolhaas's early works: simple, sharp and simultaneous. The first collages were urban proposals, as they seemed to be the only instruments sensitive and accurate enough to grasp the complexity of the city. Reality, collective memory and political ideas contained inside carefully staged images that encourage critical reflection in the viewer. Each project is a series of oppositional spaces existing in sequence, against or inside each other. The spaces are familiar but unexpected, just a step ahead of the usual. The only thing that matters is difference and complementarity. The relationships create a puzzle of history and tradition. We design the relationships, not the element.
description: piano b. Arti e culture visive, Vol 4, No 2 (2019): Collage di carta, collage digitale: concetti di architettura a confronto
Self-discharge by streaming cosmic rays
Creators: name: Ohira, Yutaka
Publisher: name: arXiv
Year: 2021
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences

description: A new nonthermal phenomenon caused by streaming cosmic rays (CRs) in the universe is proposed. The streaming CRs drive the return current of thermal electrons to compensate for the CR current. Then, electric fields are induced by the resistivity of the return current. It is shown that the resistive electric fields can accelerate secondary electrons generated by the streaming CRs. This is the self-discharge by streaming CRs. In this work, the self-discharge condition and the condition for runaway acceleration of secondary electrons are presented. The self-discharge makes high-energy secondary electrons, resulting in enhancements of ionization and nonthermal emission including K$α$ emission line of neutral irons. After the self-discharge, the return current of thermal electrons is replaced by the electric current of secondary electrons. Since some magnetic field generations and amplifications are driven by the return current of thermal electrons, the self-discharge can significantly influence them.
description: 6 pages, 1 figure, accepted for publication in ApJ
Incomplete Voyage or the Process of Reappropriation of the Fantastic
Creators: name: Peraki, IV-Irini
name: Donat-Cattin, Natalie
Publisher: name: piano b. Arti e culture visive
Year: 2020
Subjects: Representation; Montage; Storytelling; Process; Imagination

description: Contemporary society leaves little space to dream and allows only for a reduced political engagement, with few shared beliefs. We criticise, but we do not act. We protest in mass, but we are individualistic. We advocate for freedom of thought, but we are prisoners of social media and their images: images, images, images popping out everywhere, overwhelming us, suffocating us. However, representations since antiquity have always had an impact on society, as mirrors and amplifiers of the everyday. They were created to question, describe and re-imagine faiths and situations: wandering tools able to tell a common story, through individual ones. They were not “images for images”, but rather parts of a larger narration expressed through different rituals, inviting a connection with the other. The goal was to see reality with other eyes and to recognise the sur-meaning in it. On the contrary, today we are faced by a different context: the fantastic - the imaginative, dreamy or creative potential of every object or being - is either rejected or fully embraced as a substitute of the surrounding reality. Therefore, the aim of this text is to investigate how to re-create a balanced connection between reality and the fantastic, architecture and ritual, representation and myth. If performance, seen as a key tool for the expression of collectivity, will be the linking thread of the discourse, montage, thanks to its relationship to time, will be the visual, acoustic and temporal vehicle, transporting us through this α-chronic incomplete voyage.
description: piano b. Arti e culture visive, Vol 4, No 2 (2019): Collage di carta, collage digitale: concetti di architettura a confronto
On the correspondence between energy conservation and energy-momentum tensor conservation in cosmology
Creators: name: Yu, Hao
name: Gu, Bao-Min
name: Luo, Zhi
name: Li, Jin
Publisher: name: arXiv
Year: 2021
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: The correspondence between the thermodynamic energy equation satisfied by a closed co-moving volume and the conservation equation satisfied by the energy-momentum tensor of the matter inside the co-moving volume is extended to a more general system with an arbitrary cosmological horizon and a heat source. The energy of the system consisting of a cosmological horizon and its internal matter could be conserved by defining a surface energy on the horizons. Therefore, energy conservation and energy-momentum tensor conservation can always be consistent for such a system. On the other hand, from the perspective of classical thermodynamics, one can define an effective pressure at the cosmological horizon to guarantee that the thermodynamic energy equation inside the horizon is consistent with the energy-momentum tensor conservation equation of the matter inside the horizon. These systems can satisfy the generalized second law of thermodynamics under appropriate conditions. The definitions of the surface energy and the effective pressure are extended to the gravity theory with non-minimal coupling between geometry and matter, in which geometry could be regarded as a heat source.
description: 14 pages,comments are welcome
ХОТИН-ҚИЗЛАР ТОМОНИДАН СОДИР ЭТИЛАДИГАН ЖИНОЯТЛАР ПРОФИЛАКТИКАСИНИ ТАКОМИЛЛАШТИРИШ
Creators: name: Бабаханов, Ҳамдам
Publisher: name: Zenodo
Year: 2024

description: Ушбу мақолада хотин-қизлар томонидан содир этиладиган жиноятлар, ушбу жиноятларни содир этилишининг сабаблари ва уларга имкон берадиган шарт-шароитлар таҳлили ёритилган. Шу билан бирга профилактика инспекторларининг хотин-қизлар томонидан содир этиладиган жиноятлар профилактикасига доир фаолияти ва ушбу жиноятларни профилактикасини такомиллаштиришга доир илмий ва назарий таклиф тавсиялар ишлаб чиқилган.
Partition functions and entanglement entropy: Weyl graviton and conformal higher spin fields
Creators: name: Mukherjee, Jyotirmoy
Publisher: name: arXiv
Year: 2021
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We establish the relation of partition functions of conformal higher spin fields on Weyl equivalent spaces in $d=4$ dimension. We express the partition function of Weyl graviton and conformal higher spin fields as an integral over characters on $S^1\times AdS_3$, $S^4$, and $AdS_4$. We observe that the partition function of conformal higher spins on hyperbolic cylinders differs from the partition function on $S^4$ by the `edge' contribution. The logarithmic coefficient obtained from the character integral of the partition function of conformal higher spins on $AdS_4$ is the half of that obtained from the partition function on $S^4$. We evaluate the entanglement entropy and the conformal dimension of the twist operator from the partition function on the hyperbolic cylinder. The conformal dimension of the co-dimension two twist operator enables us to find a linear relation between Hofman-Maldacena variables which we use to show the non-unitarity of the theory. We observe that the spectrum of the quasinormal modes of conformal higher spins obtained from the bulk character contains additional distinct states compared to the spectrum of unitary massless higher spin fields.
description: 32 pages, 6 figures
Freezing of the Lattice in the Kagome Lattice Heisenberg Antiferromagnet Zn-barlowite ZnCu$_3$(OD)$_6$FBr
Creators: name: Wang, Jiaming
name: Yuan, Weishi
name: Singer, Philip M.
name: Smaha, Rebecca W.
name: He, Wei
name: Wen, Jiajia
name: Lee, Young S.
name: Imai, Takashi
Publisher: name: arXiv
Year: 2021
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: We use $^{79}$Br nuclear quadrupole resonance (NQR) to demonstrate that ultra slow lattice dynamics set in below the temperature scale set by the Cu-Cu super-exchange interaction $J$~($\simeq160$~K) in the kagome lattice Heisenberg antiferromagnet Zn-barlowite. The lattice completely freezes below 50~K, and $^{79}$Br NQR lineshapes become twice broader due to increased lattice distortions. Moreover, the frozen lattice exhibits an oscillatory component in the transverse spin echo decay, a typical signature of pairing of nuclear spins by indirect nuclear spin-spin interaction. This indicates that some Br sites form structural dimers via a pair of kagome Cu sites prior to the gradual emergence of spin singlets below $\sim30$~K. Our findings underscore the significant roles played by subtle structural distortions in determining the nature of the disordered magnetic ground state of the kagome lattice.
description: Phys. Rev. Lett. (in press)
Machine Learning approach to the Floquet--Lindbladian problem
Creators: name: Volokitin, V.
name: Meyerov, I.
name: Denisov, S.
Publisher: name: arXiv
Year: 2022
Subjects: subject: Quantum Physics (quant-ph)
subject: Computational Physics (physics.comp-ph)
subject: FOS: Physical sciences

description: Similar to its classical version, quantum Markovian evolution can be either time-discrete or time-continuous. Discrete quantum Markovian evolution is usually modeled with completely-positive trace-preserving maps while time-continuous evolution is often specified with superoperators referred to as "Lindbladians". Here we address the following question: Being given a quantum map, can we find a Lindbladian which generates an evolution identical -- when monitored at discrete instances of time -- to the one induced by the map? It was demonstrated that the problem of getting the answer to this question can be reduced to an NP-complete (in the dimension $N$ of the Hilbert space the evolution takes place in) problem. We approach this question from a different perspective by considering a variety of Machine Learning (ML) methods and trying to estimate their potential ability to give the correct answer. Complimentary, we use the performance of different ML methods as a tool to check the hypothesis that the answer to the question is encoded in spectral properties of the so-called Choi matrix, which can be constructed from the given quantum map. As a test bed, we use two single-qubit models for which the answer can be obtained by using the reduction procedure. The outcome of our experiment is that, for a given map, the property of being generated by a time-independent Lindbladian is encoded both in the eigenvalues and the eigenstates of the corresponding Choi matrix.
Scattering of a plane wave by an inhomogeneous 1D dielectric layer with gradient refractive index
Creators: name: Vanyushkin, N. A.
name: Gevorgyan, A. H.
name: Golik, S. S.
Publisher: name: arXiv
Year: 2022
Subjects: subject: Optics (physics.optics)
subject: FOS: Physical sciences

description: We propose a new method for calculating reflection and transmission coefficients for an arbitrarily polarized electromagnetic plane wave incident on a one-dimensional dielectric medium of finite thickness and with dielectric permittivity being an arbitrary continuous function of the coordinate. We have shown that the problem of plane wave scattering by an inhomogeneous layer is reduced to a system of first order differential equations that contain the derivative of the refractive index or dielectric permittivity of the layer, which can be used, for example, when searching for an analytical solution. This method also makes it easy to obtain the distribution of the field strength within the layer. The reflection spectra and field distribution obtained using this method were compared with the analytical solution based on Mathieu functions.
description: 14 pages, 11 figures
An accelerator experiment for junior and senior high school students to improve students' involvement in fundamental physics
Creators: name: Tanaka, K. S.
name: Harada, K.
name: Hayamizu, T.
name: Kita, R.
name: Kono, R.
name: Maruta, K.
name: Nagahama, H.
name: Ozawa, N.
name: Sakemi, Y.
name: Sugimori, R.
Publisher: name: arXiv
Year: 2022
Subjects: subject: Physics Education (physics.ed-ph)
subject: Nuclear Experiment (nucl-ex)
subject: Accelerator Physics (physics.acc-ph)
subject: Atomic Physics (physics.atom-ph)
subject: FOS: Physical sciences

description: In Japan, research activities by junior and senior high school students show an upward trend. However, there are limited examples of research activities in the field of elementary particles and atoms. This is due to the difficulty associated with procuring research tools such as accelerators or particle detectors. Therefore, we hosted the "Accel Kitchen" in 2018 and 2019 at Cyclotron and Radioisotope Center (CYRIC) in Tohoku University where junior and senior high school students could participate in ongoing research of particle and atomic physics. At each workshop, 12 junior and senior high school students participated in the beam experiment, including the production of francium atoms (Fr) by the fusion reaction of oxygen and gold, optimizing the transport of the ion beam and identifying the alpha decay nuclei, and laser trapping of Fr for two days. Each group that was involved in the experiment was supported by researchers and university students who acted as mentors. This was the first opportunity for junior and senior high school students to know about the particle beam experiment in Japan.
description: 8 pages, 18 figure
Dynamical tuning of the chemical potential to achieve a target particle number in grand canonical Monte Carlo simulations
Creators: name: Miles, Cole
name: Cohen-Stead, Benjamin
name: Bradley, Owen
name: Johnston, Steven
name: Scalettar, Richard
name: Barros, Kipton
Publisher: name: arXiv
Year: 2022
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: Computational Physics (physics.comp-ph)
subject: FOS: Physical sciences

description: We present a method to facilitate Monte Carlo simulations in the grand canonical ensemble given a target mean particle number. The method imposes a fictitious dynamics on the chemical potential, to be run concurrently with the Monte Carlo sampling of the physical system. Corrections to the chemical potential are made according to time-averaged estimates of the mean and variance of the particle number, with the latter being proportional to thermodynamic compressibility. We perform a variety of tests, and in all cases find rapid convergence of the chemical potential -- inexactness of the tuning algorithm contributes only a minor part of the total measurement error for realistic simulations.
description: 10 pages, 6 figures
Hyperon production in quasielastic $\barν_τ-$nucleon scattering
Creators: name: Fatima, A.
name: Athar, M. Sajjad
name: Singh, S. K.
Publisher: name: arXiv
Year: 2022
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: High Energy Physics - Experiment (hep-ex)
subject: Nuclear Theory (nucl-th)
subject: FOS: Physical sciences

description: The theoretical results for the total cross sections and polarization components of the $τ^{+}$ lepton produced in the charged current induced $|ΔS| = 1$ quasielastic $\barν_τ- N$ scattering leading to hyperons ($Λ, Σ$) have been presented assuming T invariance. The theoretical uncertainties arising due to the use of different vector, axial vector and pseudoscalar form factors as well as the effect of SU(3) symmetry breaking have been studied. We have also presented, for the first time, a comparison of the total cross sections for the production of $e,μ,τ$ leptons to facilitate the implications of lepton flavor universality~(LFU) in the $|ΔS| = 1$ quasielastic reactions induced by the antineutrinos of all flavors i.e., $ν_{l};~l=e,μ,τ$.
description: 23 pages, 15 figures and 1 table. arXiv admin note: text overlap with arXiv:2010.10311
Selective nuclear-spin interaction based on a dissipatively stabilized nitrogen-vacancy center
Creators: name: Jiang, Jiawen
name: Chen, Q.
Publisher: name: arXiv
Year: 2022
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: Current typical methods to realize nuclear-nuclear quantum gates require a sequence of electronnuclear quantum gates by using dynamical decoupling techniques, which are implemented at low temperature because of short decoherence and relaxation time of the NV spin at room temperature. This limitation could be overcome by using periodical resets of an NV spin as a mediator of interaction between two nuclear spins [Chen, Schwarz, and Plenio, 119, 010801 (2017)]. However, this method works under stringent coupling strengths condition, which makes it not applicable to heteronuclear quantum gate operations. Here we develop this scheme by using radio-frequency (RF) fields to control different nuclear spin species. Periodical resets of the NV center protect the nuclear spins from decoherence and relaxation of the NV spin. RF control provides probability to have highly selective and high fidelity quantum gates between heteronuclear spins as well as detecting nuclear spins by using a nuclear spin sensor under ambient conditions.