cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Edge-induced Schottky barrier modulation at metal contacts to exfoliated molybdenum disulfide flakes
Creators: name: Nouchi, Ryo
Publisher: name: arXiv
Year: 2016
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: Ultrathin two-dimensional semiconductors obtained from layered transition-metal dichalcogenides such as molybdenum disulfide (MoS2) are promising for ultimately scaled transistors beyond Si. Although the shortening of the semiconductor channel is widely studied, the narrowing of the channel, which should also be important for scaling down the transistor, has been examined to a lesser degree thus far. In this study, the impact of narrowing on mechanically exfoliated MoS2 flakes was investigated according to the channel-width-dependent Schottky barrier heights at Cr/Au contacts. Narrower channels were found to possess a higher Schottky barrier height, which is ascribed to the edge-induced band bending in MoS2. The higher barrier heights degrade the transistor performance as a higher electrode-contact resistance. Theoretical analyses based on Poisson's equation showed that the edge-induced effect can be alleviated by a high dopant impurity concentration, but this strategy should be limited to channel widths of roughly 0.7 micrometers because of the impurity-induced charge-carrier mobility degradation. Therefore, proper termination of the dangling bonds at the edges should be necessary for aggressive scaling with layered semiconductors.
description: Accepted for publication in Journal of Applied Physics
Perspectives With The GCT End-to-end Prototype Of The Small-Sized Telescope Proposed For The Cherenkov Telescope Array
Creators: name: Costantini, H.
name: Dournaux, J. -L.
name: Ernenwein, J. -P.
name: Laporte, Ph.
name: Sol, H.
Publisher: name: arXiv
Year: 2016
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: Instrumentation and Methods for Astrophysics (astro-ph.IM)
subject: FOS: Physical sciences

description: In the framework of the Cherenkov Telescope Array (CTA), the GCT (Gamma-ray Cherenkov Telescope) team is building a dual-mirror telescope as one of the proposed prototypes for the CTA small size class of telescopes. The telescope is based on a Schwarzschild- Couder (SC) optical design, an innovative solution for ground-based Cherenkov astronomy, which allows a compact telescope structure, a lightweight large Field of View (FoV) camera and enables good angular resolution across the entire FoV. We review the different mechanical and optical components of the telescope. In order to characterise them, the Paris prototype will be operated during several weeks in 2016. In this framework, an estimate of the expected performance of this prototype has been made, based on Monte Carlo simulations. In particular the observability of the Crab Nebula in the context of high Night Sky Background (NSB) is presented.
description: In Proceedings of the 2016 Heidelberg Symposium on High Energy Gamma-Ray Astronomy
Speciesist Language and Nonhuman Animal Bias in English Masked Language Models
Creators: name: Takeshita, Masashi
name: Rzepka, Rafal
name: Araki, Kenji
Publisher: name: arXiv
Year: 2022
Subjects: subject: Computation and Language (cs.CL)
subject: FOS: Computer and information sciences

description: Various existing studies have analyzed what social biases are inherited by NLP models. These biases may directly or indirectly harm people, therefore previous studies have focused only on human attributes. However, until recently no research on social biases in NLP regarding nonhumans existed. In this paper, we analyze biases to nonhuman animals, i.e. speciesist bias, inherent in English Masked Language Models such as BERT. We analyzed speciesist bias against 46 animal names using template-based and corpus-extracted sentences containing speciesist (or non-speciesist) language. We found that pre-trained masked language models tend to associate harmful words with nonhuman animals and have a bias toward using speciesist language for some nonhuman animal names. Our code for reproducing the experiments will be made available on GitHub.
description: This paper is an accepted manuscript for publication in Information Processing & Management
Lasing versus lasing without inversion in an optically thin gain medium near a metal surface
Creators: name: Bordo, V. G.
Publisher: name: arXiv
Year: 2022
Subjects: subject: Optics (physics.optics)
subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: A theory of lasing in an optically thin layer of active centers disposed at a metal surface is developed from first principles. The approach is based on a rigorous account of the local field in a close vicinity of a reflective surface which provides a feedback for dipole oscillations in active centers. It is demonstrated that the gain medium thickness plays a crucial role in the lasing condition and controls a switching from conventional lasing to lasing without inversion. The numerical calculations are carried out for erbium doped glass bordering a gold surface where radiation at telecom wavelength (1532 nm) can be generated.
description: 9 pages, 3 figures. arXiv admin note: substantial text overlap with arXiv:2111.11746
From amaurotic idiocy to biochemically defined lipid storage diseases: the first identification of GM1-Gangliosidosis
Creators: name: Kasper, Burkhard S
name: Thomas, Christian
name: Albers, Anne
name: Kasper, Ekkehard
name: Sandhoff, Konrad
Publisher: name: Free Neuropathology
Year: 2023
Subjects: Lipid storage disease
GM1-Gangliosidosis
Amaurotic idiocy
Tay-Sachs-Disease
Beta-galactosidase

description: On February 23rd 1936, a boy-child (“Kn”) died in an asylum near Munich after years of severe congenital dis-ease, which had profoundly impaired his development leading to inability to walk, talk and see as well as to severe epilepsy. While a diagnosis of “Little’s disease” was made during life, his postmortem brain investiga-tion at Munich neuropathology (“Deutsche Forschungsanstalt für Psychiatrie”) revealed the diagnosis of “amaurotic idiocy” (AI). AI, as exemplified by Tay-Sachs-Disease (TSD), back then was not yet understood as a specific inborn error of metabolism encompassing several disease entities. Many neuropathological studies were performed on AI, but the underlying processes could only be revealed by new scientific techniques such as biochemical analysis of nervous tissue, deciphering AI as nervous system lipid storage diseases, e.g. GM2-gangliosidosis. In 1963, Sandhoff & Jatzkewitz published an article on a “biochemically special form of AI” reporting striking differences when comparing their biochemical observations of hallmark features of TSD to tissue composition in a single case: the boy Kn. This was the first description of “GM1-Gangliosidosis”, later understood as resulting from genetically determined deficiency in beta-galactosidase. Here we present illus-trative materials from this historic patient, including selected diagnostic slides from the case “Kn” in virtual microscopy, original records and other illustrative material available. Finally, we present results from genetic analysis performed on archived tissue proving beta-galactosidase-gene mutation, verifying the 1963 interpre-tation as correct. This synopsis shall give a first-hand impression of this milestone finding in neuropathology.
description: Free Neuropathology, Bd. 4 (2023)
Engineering entanglement between resonators by hot environment
Creators: name: Naseem, M. Tahir
name: Müstecaplıoğlu, Özgür E.
Publisher: name: arXiv
Year: 2022
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: Autonomous quantum thermal machines do not require an external coherent drive or work input to perform the desired tasks, which makes them a promising candidate for thermal management in quantum systems. Here, we propose an autonomous quantum thermal machine in which two uncoupled macroscopic mechanical resonators or microwave resonators achieve considerable entanglement via a hot thermal bath. This becomes possible by coupling the resonators to a common two-level system or third harmonic oscillator and driving it by the hot incoherent thermal bath. The critical step to make the entanglement involves suitable engineering of the hot bath, realized by bath spectrum filtering. Our results suggest that the bath spectrum filtering can be an alternative to typical non-autonomous reservoir engineering schemes to create exotic quantum states.
description: Accepted in Quantum Science and Technology
Some dependence results between the spreading speed and the coefficients of the space--time periodic Fisher--KPP equation
Creators: name: Nadin, Grégoire
Publisher: name: arXiv
Year: 2016
Subjects: subject: Analysis of PDEs (math.AP)
subject: Optimization and Control (math.OC)
subject: FOS: Mathematics

description: We investigate in this paper the dependence relation between the space-time periodic coefficients $A, q$ and $μ$ of the reaction-diffusion equation $\partial_t u - \nabla \cdot (A(t, x)\nabla u) + q(t, x) \cdot \nabla u = μ(t, x) u(1 - u)$, and the spreading speed of the solutions of the Cauchy problem associated with this equation and compactly supported initial data. We prove in particular that (1) taking the spatial or temporal average of $μ$ decreases the minimal speed, (2) if the coefficients do not depend on $t$ and $q\not\equiv 0$, then increasing the amplitude of the diffusion matrix $A$ increases the minimal speed, (3) if $A = I_N$, $μ$ is a constant, then the introduction of a space periodic drift term $q = \nabla Q$ increases the minimal speed. To prove these results, we use a variational characterization of the spreading speed that involves a family of periodic principal eigenvalues associated with the linearization of the equation near 0. We are thus back to the investigation of the dependence relation between this family of eigenvalues and the coefficients.
Dynamical ejecta from precessing neutron star-black hole mergers with a hot, nuclear-theory based equation of state
Creators: name: Foucart, Francois
name: Desai, Dhruv
name: Brege, Wyatt
name: Duez, Matthew D.
name: Kasen, Daniel
name: Hemberger, Daniel A.
name: Kidder, Lawrence E.
name: Pfeiffer, Harald P.
name: Scheel, Mark A.
Publisher: name: arXiv
Year: 2016
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: Neutron star-black hole binaries are among the strongest sources of gravitational waves detectable by current observatories. They can also power bright electromagnetic signals (gamma-ray bursts, kilonovae), and may be a significant source of production of r-process nuclei. A misalignment of the black hole spin with respect to the orbital angular momentum leads to precession of that spin and of the orbital plane, and has a significant effect on the properties of the post-merger remnant and of the material ejected by the merger. We present a first set of simulations of precessing neutron star-black hole mergers using a hot, composition dependent, nuclear-theory based equation of state (DD2). We show that the mass of the remnant and of the dynamical ejecta are broadly consistent with the result of simulations using simpler equations of state, while differences arise when considering the dynamics of the merger and the velocity of the ejecta. We show that the latter can easily be understood from assumptions about the composition of low-density, cold material in the different equations of state, and propose an updated estimate for the ejecta velocity which takes those effects into account. We also present an updated mesh-refinement algorithm which allows us to improve the numerical resolution used to evolve neutron star-black hole mergers.
description: 23 pages, 8 figures
Automated fault tree learning from continuous-valued sensor data: a case study on domestic heaters
Creators: name: Verkuil, Bart
name: Budde, Carlos E.
name: Bucur, Doina
Publisher: name: arXiv
Year: 2022
Subjects: subject: Machine Learning (cs.LG)
subject: Artificial Intelligence (cs.AI)
subject: Computational Engineering, Finance, and Science (cs.CE)
subject: FOS: Computer and information sciences

description: Many industrial sectors have been collecting big sensor data. With recent technologies for processing big data, companies can exploit this for automatic failure detection and prevention. We propose the first completely automated method for failure analysis, machine-learning fault trees from raw observational data with continuous variables. Our method scales well and is tested on a real-world, five-year dataset of domestic heater operations in The Netherlands, with 31 million unique heater-day readings, each containing 27 sensor and 11 failure variables. Our method builds on two previous procedures: the C4.5 decision-tree learning algorithm, and the LIFT fault tree learning algorithm from Boolean data. C4.5 pre-processes each continuous variable: it learns an optimal numerical threshold which distinguishes between faulty and normal operation of the top-level system. These thresholds discretise the variables, thus allowing LIFT to learn fault trees which model the root failure mechanisms of the system and are explainable. We obtain fault trees for the 11 failure variables, and evaluate them in two ways: quantitatively, with a significance score, and qualitatively, with domain specialists. Some of the fault trees learnt have almost maximum significance (above 0.95), while others have medium-to-low significance (around 0.30), reflecting the difficulty of learning from big, noisy, real-world sensor data. The domain specialists confirm that the fault trees model meaningful relationships among the variables.
Orbital-Exchange and Fractional Quantum Number Excitations in an f-electron Metal Yb$_2$Pt$_2$Pb
Creators: name: Wu, L. S.
name: Gannon, W. J.
name: Zaliznyak, I. A.
name: Tsvelik, A. M.
name: Brockmann, M.
name: Caux, J. -S.
name: Kim, M. S.
name: Qiu, Y.
name: Copley, J. R. D.
name: Ehlers, G.
name: Podlesnyak, A.
name: Aronson, M. C.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: Exotic quantum states and fractionalized magnetic excitations, such as spinons in one-dimensional chains, are generally viewed as belonging to the domain of 3d transition metal systems with spins 1/2. Our neutron scattering experiments on the 4f-electron metal Yb$_2$Pt$_2$Pb overturn this common wisdom. We observe broad magnetic continuum dispersing in only one direction, which indicates that the underlying elementary excitations are spinons carrying fractional spin-1/2. These spinons are the quantum dynamics of the anisotropic, orbital-dominated Yb moments, and thus these effective quantum spins are emergent variables that encode the electronic orbitals. The unique birthmark of their unusual origin is that only longitudinal spin fluctuations are measurable, while the transverse excitations such as spin waves are virtually invisible to magnetic neutron scattering. The proliferation of these orbital-spinons strips the electrons of their orbital identity, and we thus report here a new electron fractionalization phenomenon, charge-orbital separation.
description: Manuscript (15 pages, 4 figures) merged with the Supplementary Information (33 pages, 10 figures)
An Efficient Method for Simulating Light Curves of Cosmological Microlensing and Caustic Crossing Events
Creators: name: Meena, Ashish Kumar
name: Arad, Ofir
name: Zitrin, Adi
Publisher: name: arXiv
Year: 2022
Subjects: subject: Instrumentation and Methods for Astrophysics (astro-ph.IM)
subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: FOS: Physical sciences

description: A new window to observing individual stars and other small sources at cosmological distances was opened recently, with the detection of several caustic-crossing events in galaxy cluster fields. Many more such events are expected soon from dedicated campaigns with the \emph{Hubble Space Telescope} and from the \emph{James Webb Space Telescope}. These events can teach us not only about the lensed sources themselves, such as individual high-redshift stars, star clusters, or accretion disks, but through their light-curves they also hold information about the point-mass function of the lens and thus, potentially, the composition of dark matter. We present here a simple method for simulating light curves of such events, i.e., the change in apparent magnitude of the source as it sweeps over the net of caustics generated by microlenses embedded around the critical region of the lens. The method is recursive and so any reasonably sized small source can be accommodated, down to sub-solar scales, in principle. We compare the method, which we dub \emph{Adaptive Boundary Method}, with other common methods such as simple inverse ray shooting, and demonstrate that it is significantly more efficient and accurate in the small-source and high-magnification regime of interest. A \textsc{python} version of the code is made publicly available in an open-source fashion for simulating future events.
description: 16 pages; 7 figures; 3 tables; Accepted in MNRAS
Spin-optical dynamics and quantum efficiency of single V1 center in silicon carbide
Creators: name: Morioka, Naoya
name: Liu, Di
name: Soykal, Öney O.
name: Gediz, Izel
name: Babin, Charles
name: Stöhr, Rainer
name: Ohshima, Takeshi
name: Son, Nguyen Tien
name: Ul-Hassan, Jawad
name: Kaiser, Florian
name: Wrachtrup, Jörg
Publisher: name: arXiv
Year: 2022
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: Color centers in silicon carbide are emerging candidates for distributed spin-based quantum applications due to the scalability of host materials and the demonstration of integration into nanophotonic resonators. Recently, silicon vacancy centers in silicon carbide have been identified as a promising system with excellent spin and optical properties. Here, we in-depth study the spin-optical dynamics of single silicon vacancy center at hexagonal lattice sites, namely V1, in 4H-polytype silicon carbide. By utilizing resonant and above-resonant sub-lifetime pulsed excitation, we determine spin-dependent excited-state lifetimes and intersystem-crossing rates. Our approach to inferring the intersystem-crossing rates is based on all-optical pulsed initialization and readout scheme, and is applicable to spin-active color centers with similar dynamics models. In addition, the optical transition dipole strength and the quantum efficiency of V1 defect are evaluated based on coherent optical Rabi measurement and local-field calibration employing electric-field simulation. The measured rates well explain the results of spin-state polarization dynamics, and we further discuss the altered photoemission dynamics in resonant enhancement structures such as radiative lifetime shortening and Purcell enhancement. By providing a thorough description of V1 center's spin-optical dynamics, our work provides deep understanding of the system which guides implementations of scalable quantum applications based on silicon vacancy centers in silicon carbide.
description: 32 pages, 12 figures
A low-temperature external cavity diode laser for broad wavelength tuning
Creators: name: Tobias, William G.
name: Rosenberg, Jason S.
name: Hutzler, Nicholas R.
name: Ni, Kang-Kuen
Publisher: name: arXiv
Year: 2016
Subjects: subject: Atomic Physics (physics.atom-ph)
subject: Chemical Physics (physics.chem-ph)
subject: Instrumentation and Detectors (physics.ins-det)
subject: FOS: Physical sciences

description: We report on the design and characterization of a low-temperature external cavity diode laser (ECDL) system for broad wavelength tuning. The performance achieved with multiple diode models addresses the scarcity of commercial red laser diodes below 633 nm, which is a wavelength range relevant to spectroscopy of many molecules and ions. Using a combination of multiple-stage thermoelectric cooling and water cooling, the operating temperature of a laser diode is lowered to -64°C, more than 85°C below the ambient temperature. The laser system integrates temperature and diffraction grating feedback tunability for coarse and fine wavelength adjustments, respectively. For two different diode models, single-mode operation was achieved with 38 mW output power at 616.8 nm and 69 mW at 622.6 nm, more than 15 nm below their ambient temperature free-running wavelengths. The ECDL design can be used for diodes of any available wavelength, allowing individual diodes to be tuned continuously over tens of nanometers and extending the wavelength coverage of commercial laser diodes.
description: 6 pages, 6 figures
Sex Trouble: Common pitfalls in incorporating sex/gender in medical machine learning and how to avoid them
Creators: name: Albert, Kendra
name: Delano, Maggie
Publisher: name: arXiv
Year: 2022
Subjects: subject: Computers and Society (cs.CY)
subject: Machine Learning (cs.LG)
subject: FOS: Computer and information sciences

description: False assumptions about sex and gender are deeply embedded in the medical system, including that they are binary, static, and concordant. Machine learning researchers must understand the nature of these assumptions in order to avoid perpetuating them. In this perspectives piece, we identify three common mistakes that researchers make when dealing with sex/gender data: "sex confusion", the failure to identity what sex in a dataset does or doesn't mean; "sex obsession", the belief that sex, specifically sex assigned at birth, is the relevant variable for most applications; and "sex/gender slippage", the conflation of sex and gender even in contexts where only one or the other is known. We then discuss how these pitfalls show up in machine learning studies based on electronic health record data, which is commonly used for everything from retrospective analysis of patient outcomes to the development of algorithms to predict risk and administer care. Finally, we offer a series of recommendations about how machine learning researchers can produce both research and algorithms that more carefully engage with questions of sex/gender, better serving all patients, including transgender people.
description: submitted to Cell Patterns as a perspective article
The emergence and analysis of Kuramoto-Sakaguchi-like models as an effective description for the dynamics of coupled Wien-bridge oscillators
Creators: name: English, L. Q.
name: Mertens, David
name: Abdoulkary, Saidou
name: Fritz, C. B.
name: Skowronski, K.
name: Kevrekidis, P. G.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Pattern Formation and Solitons (nlin.PS)
subject: FOS: Physical sciences

description: We derive the Kuramoto-Sakaguchi model from the basic circuit equations governing two coupled Wien-bridge oscillators. A Wien-bridge oscillator is a particular realization of a tunable autonomous oscillator that makes use of frequency filtering (via a RC band-pass filter) and positive feedback (via an Op-Amp). In the last few years, such oscillators have started to be utilized in synchronization studies. We first show that the Wien-bridge circuit equations can be cast in the form of a coupled pair of Duffing - Van der Pol equations. Subsequently, by applying the method of multiple time scales, we derive the differential equations that govern the slow evolution of the oscillator phases and amplitudes. These equations are directly reminiscent of the Kuramoto-Sakaguchi type models for the study of synchronization. We analyze the resulting system in terms of existence and stability of various coupled oscillator solutions and explain on that basis how their synchronization emerges. The phase-amplitude equations are also compared numerically to the original circuit equations, and good agreement is found. Finally, we report on experimental measurements on two coupled Wien-bridge oscillators and relate the results back to the theoretical predictions.
description: 13 pages, 7 figures
The Unusual Galactic Center Radio Source N3
Creators: name: Ludovici, Dominic A.
name: Lang, Cornelia C.
name: Morris, Mark R.
name: Mutel, Robert
name: Mills, Elisabeth A. C.
name: Toomey, James E
name: Ott, Juergen
Publisher: name: arXiv
Year: 2016
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: Here we report on new, multi-wavelength radio observations of the unusual point source "N3" that appears to be located in the vicinity of the Galactic Center. VLA observations between 2 and 50 GHz reveal that N3 is a compact and bright source (56 mJy at 10 GHz) with a non-thermal spectrum superimposed upon the non-thermal radio filaments (NTFs) of the Radio Arc. Our highest frequency observations place a strict upper limit of 65 x 28 mas on the size of N3. We compare our observations to those of Yusef-Zadeh & Morris (1987) and Lang et al. (1997) and conclude that N3 is variable over long time scales. Additionally, we present the detection of a compact molecular cloud located adjacent to N3 in projection. CH3CN, CH3OH, CS, HC3N, HNCO, SiO, SO, and NH3 are detected in the cloud and most transitions have FWHM line widths of ~20 km/s. The rotational temperature determined from the metastable NH3 transitions ranges from 79 K to 183 K depending on the transitions used. We present evidence that this molecular cloud is interacting with N3. After exploring the relationship between the NTFs, molecular cloud, and N3, we conclude that N3 likely lies within the Galactic Center. We are able to rule out the HII region, young supernova, active star, AGN, and micro-quasar hypotheses for N3. While a micro-blazar may provide a viable explanation for N3, additional observations are needed to determine the physical counterpart of this mysterious source.
description: Accepted for publication in The Astrophysical Journal. 19 pages, 11 figures
One-loop structure of the U(1) gauge model on the truncated Heisenberg space
Creators: name: Burić, Maja
name: Nenadović, Luka
name: Prekrat, Dragan
Publisher: name: arXiv
Year: 2016
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We calculate divergent one-loop corrections to the propagators of the U(1) gauge theory on the truncated Heisenberg space, which is one of the extensions of the Grosse-Wulkenhaar model. The model is purely geometric, based on the Yang-Mills action; the corresponding gauge-fixed theory is BRST invariant. We quantize perturbatively and, along with the usual wave-function and mass renormalizations, we find divergent nonlocal terms of the $\Box^{-1}$ and $\Box^{-2}$ type. We discuss the meaning of these terms and possible improvements of the model.
description: 29 pages
Semi-classical simulation of spin-1 magnets
Creators: name: Remund, Kimberly
name: Pohle, Rico
name: Akagi, Yutaka
name: Romhányi, Judit
name: Shannon, Nic
Publisher: name: arXiv
Year: 2022
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: FOS: Physical sciences

description: Theoretical studies of magnets have traditionally concentrated on either classical spins, or the extreme quantum limit of spin-1/2. However, magnets built of spin-1 moments are also intrinsically interesting, not least because they can support quadrupole, as well as dipole moments, on a single site. For this reason, spin-1 models have been extensively studied as prototypes for quadrupolar (spin-nematic) order in magnetic insulators, and Fe-based superconductors. At the same time, because of the presence of quadrupoles, the classical limit of a spin-1 moment is not an $O(3)$ vector, a fact which must be taken into account in describing their properties. In this Article we develop a method to simulate spin-1 magnets based on a $u(3)$ algebra which treats both dipole and quadrupole moments on equal footing. This approach is amenable to both classical and quantum calculations, and we develop the techniques needed to calculate thermodynamic properties through Monte Carlo simulations and classical low-temperature expansion, and dynamical properties, through "molecular dynamics" simulations and a multiple-boson expansion. As a case study, we present detailed analytic and numerical results for the thermodynamic properties of ferroquadrupolar order on the triangular lattice, and its associated dynamics. At low temperatures, we show that it is possible to "correct" for the effects of classical statistics in simulations, and extrapolate to the zero-temperature quantum results found in flavour-wave theory.
description: 66 pages and 24 figures
Cosmology with Phase Statistics: Parameter Forecasts and Detectability of BAO
Creators: name: Eggemeier, Alexander
name: Smith, Robert E.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: FOS: Physical sciences

description: We consider an alternative to conventional three-point statistics such as the bispectrum, which is purely based on the Fourier phases of the density field: the line correlation function. This statistic directly probes the non-linear clustering regime and contains information highly complementary to that contained in the power spectrum. In this work, we determine, for the first time, its potential to constrain cosmological parameters and detect baryon acoustic oscillations (hereafter BAOs). We show how to compute the line correlation function for a discrete sampled set of tracers that follow a local Lagrangian biasing scheme and demonstrate how it breaks the degeneracy between the amplitude of density fluctuations and the bias parameters of the model. We then derive analytic expressions for its covariance and show that it can be written as a sum of a Gaussian piece plus non-Gaussian corrections. We compare our predictions with a large ensemble of $N$-body simulations and confirm that BAOs do indeed modulate the signal of the line correlation function for scales $50$-$100\,h^{-1}\,\mathrm{Mpc}$, and that the characteristic S-shape feature would be detectable in upcoming Stage IV surveys at the level of $\sim4σ$. We then focus on the cosmological information content and compute Fisher forecasts for an idealized Stage III galaxy redshift survey of volume $V\sim 10\,h^{-3}\,\mathrm{Gpc}^3$ and out to $z=1$. We show that, combining the line correlation function with the galaxy power spectrum and a Planck-like microwave background survey, yields improvements up to a factor of two for parameters such as $σ_8$, $b_1$ and $b_2$, compared to using only the two-point information alone.
description: 19+3 pages, 12 figures, 2 tables
Relating Siegel cusp forms to Siegel-Maaß forms
Creators: name: Kramer, Jürg
name: Mandal, Antareep
Publisher: name: arXiv
Year: 2022
Subjects: subject: Number Theory (math.NT)
subject: FOS: Mathematics

description: In this paper we generalize a well-known isomorphism between the space of cusp forms of weight $k$ for a Fuchsian subgroup of the first kind $Γ\subset\mathrm{SL}_{2}(\mathbb{R})$ and the space of certain Maaß forms of weight $k$ for $Γ$ to an isomorphism between the space of Siegel cusp forms of weight $k$ for a subgroup $Γ\subset\mathrm{Sp}_{n}(\mathbb{R})$, which is commensurable with the Siegel modular group $\mathrm{Sp}_{n}(\mathbb{Z})$, and a suitable space of Siegel-Maaß forms of weight $k$ for $Γ$.
Observation of two distinct pairs fluctuation lifetimes and supercurrents in the pseudogap regime of cuprate junctions
Creators: name: Koren, Gad
name: Lee, Patrick A.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Superconductivity (cond-mat.supr-con)
subject: FOS: Physical sciences

description: Pairs fluctuation supercurrents and inverse lifetimes were measured on epitaxial c-axis junctions of the cuprates in the pseudogap regime, with a $PrBa_2Cu_3O_{7-δ}$ barrier sandwiched in between two $YBa_2Cu_3O_{7-δ}$ or doped $YBa_2Cu_3O_y$ electrodes, with or without magnetic fields parallel to the a-b planes. All junctions had a $\rm T_c(high)\approx 85-90$ K and a $\rm T_c(low)\approx 50-55$ K electrodes, allowing us to study pairs fluctuation supercurrents and inverse life times in between these two temperatures. In junctions with a pseudogap electrode under zero field, an excesss current due to pair fluctuations was observed which persisted at temperatures above $\rm T_c(low)$, in the pseudogap regime, and up to about $\rm T_c(high)$. No such excess current was observed in junctions without a pseudo-gap in the electrode. The measured conductance spectra at temperatures above $\rm T_c(low)$ were fitted using a modified fluctuations model by Scalapino [Phys. Rev. Lett. \textbf{24}, 1052(1970)] of a junction with a serial resistance. We found that in the pseudo-gap regime, the conductance vs voltage consists of a narrow peak sitting on top of a very broad peak. This yielded two distinct pairs fluctuation lifetimes in the pseudogap electrode which differ by an order of magnitude up to about $\rm T_c(high)$. Under in-plane fields, these two lifetime values remain separated in two distinct groups, which varied with increasing field moderately. We also found that detection of Amperian pairing [Phys. Rev. X \textbf{4}, 031017 (2014)] in our cuprate junctions is not feasible, due to Josephson vortices penetration into the superconducting electrodes which drove the necessary field above the depairing field.
description: 29 pages, 7+2 figures, Comments are welcome
Root-aligned SMILES: A Tight Representation for Chemical Reaction Prediction
Creators: name: Zhong, Zipeng
name: Song, Jie
name: Feng, Zunlei
name: Liu, Tiantao
name: Jia, Lingxiang
name: Yao, Shaolun
name: Wu, Min
name: Hou, Tingjun
name: Song, Mingli
Publisher: name: arXiv
Year: 2022
Subjects: subject: Machine Learning (cs.LG)
subject: Chemical Physics (physics.chem-ph)
subject: Biomolecules (q-bio.BM)
subject: FOS: Computer and information sciences
subject: FOS: Physical sciences
subject: FOS: Biological sciences

description: Chemical reaction prediction, involving forward synthesis and retrosynthesis prediction, is a fundamental problem in organic synthesis. A popular computational paradigm formulates synthesis prediction as a sequence-to-sequence translation problem, where the typical SMILES is adopted for molecule representations. However, the general-purpose SMILES neglects the characteristics of chemical reactions, where the molecular graph topology is largely unaltered from reactants to products, resulting in the suboptimal performance of SMILES if straightforwardly applied. In this article, we propose the root-aligned SMILES (R-SMILES), which specifies a tightly aligned one-to-one mapping between the product and the reactant SMILES for more efficient synthesis prediction. Due to the strict one-to-one mapping and reduced edit distance, the computational model is largely relieved from learning the complex syntax and dedicated to learning the chemical knowledge for reactions. We compare the proposed R-SMILES with various state-of-the-art baselines and show that it significantly outperforms them all, demonstrating the superiority of the proposed method.
description: Chemical Science 2022. Main paper: 16 pages, 5 figures, and 6 tables; supplementary information: 8 pages, 5 figures and 3 tables. Code repository: https://github.com/otori-bird/retrosynthesis
Control of light-atom solitons and atomic transport by optical vortex beams propagating through a Bose-Einstein Condensate
Creators: name: Henderson, Grant
name: Robb, Gordon R. M.
name: Oppo, Gian-Luca
name: Yao, Alison M.
Publisher: name: arXiv
Year: 2022
Subjects: subject: Quantum Gases (cond-mat.quant-gas)
subject: Pattern Formation and Solitons (nlin.PS)
subject: Optics (physics.optics)
subject: FOS: Physical sciences

description: We model propagation of far-red-detuned optical vortex beams through a Bose-Einstein Condensate using nonlinear Schrödinger and Gross-Pitaevskii equations. We show the formation of coupled light/atomic solitons that rotate azimuthally before moving off tangentially, carrying angular momentum. The number, and velocity, of solitons, depends on the orbital angular momentum of the optical field. Using a Bessel-Gauss beam increases radial confinement so that solitons can rotate with fixed azimuthal velocity. Our model provides a highly controllable method of channelling a BEC and atomic transport.
description: 5 pages, 4 figures
Quantum annealing with pairs of $^2Σ$ molecules as qubits
Creators: name: Asnaashari, K.
name: Krems, R. V.
Publisher: name: arXiv
Year: 2022
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: The rotational and fine structure of open-shell molecules in a $Σ$ electronic state gives rise to crossings between Zeeman states of different parity. These crossings become avoided in the presence of an electric field. We propose an algorithm that encodes Ising models into qubits defined by pairs of $^2Σ$ molecules sharing an excitation near these avoided crossings. This can be used to realize a transverse field Ising model tunable by an external electric or magnetic field, suitable for quantum annealing applications. We perform dynamical calculations for several examples with one- and two-dimensional connectivities. Our results demonstrate that the probability of obtaining valid annealing solutions is high and can be optimized by varying the annealing times.
description: 14 pages, 10 figures
Researches on a reactor core in heavy ion inertial fusion
Creators: name: Kondo, S.
name: Karino, T.
name: Iinuma, T.
name: Kubo, K.
name: Kato, H.
name: Kawata, S.
name: Ogoyski, A. I.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Plasma Physics (physics.plasm-ph)
subject: FOS: Physical sciences

description: In this paper a study on a fusion reactor core is presented in heavy ion inertial fusion (HIF), including the heavy ion beam (HIB) transport in a fusion reactor, a HIB interaction with a background gas, reactor cavity gas dynamics, the reactor gas backflow to the beam lines, and a HIB fusion reactor design. The HIB has remarkable preferable features to release the fusion energy in inertial fusion: in particle accelerators HIBs are generated with a high driver efficiency of ~30-40%, and the HIB ions deposit their energy inside of materials. Therefore, a requirement for the fusion target energy gain is relatively low, that would be ~50 to operate a HIF fusion reactor with a standard energy output of 1GW of electricity. In a fusion reactor the HIB charge neutralization is needed for a ballistic HIB transport. Multiple mechanical shutters would be installed at each HIB port at the reactor wall to stop the blast waves and the chamber gas backflow, so that the accelerator final elements would be protected from the reactor gas contaminant. The essential fusion reactor components are discussed in this paper.
description: 15 pages, 11figures, submitted to a fournal. arXiv admin note: substantial text overlap with arXiv:1511.06508
Project Icarus: Preliminary Thoughts on the Selection of Probes and Instruments for an Icarus-style Interstellar Mission
Creators: name: Crawford, Ian A.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Instrumentation and Methods for Astrophysics (astro-ph.IM)
subject: Earth and Planetary Astrophysics (astro-ph.EP)
subject: FOS: Physical sciences

description: In this paper we outline the range of probes and scientific instruments that will be required in order for Icarus to fulfill its scientific mission of exploring a nearby star, its attendant planetary system, and the intervening interstellar medium. Based on this preliminary analysis, we estimate that the minimum total Icarus scientific payload mass (i.e. the mass of probes and instruments which must be decelerated to rest in the target system to enable a meaningful programme of scientific investigation) will be in the region of 100 tonnes. Of this, approximately 10 tonnes would be allocated for cruise-phase science instruments, and about 35 tonnes (i.e. the average of estimated lower and upper limits of 28 and 41 tonnes) would be contributed by the intra-system science payload itself (i.e. the dry mass of the stellar and planetary probes and their instruments). The remaining ~55 tonnes is allocated for the sub-probe intra-system propulsion requirements (crudely estimated from current Solar System missions; detailed modelling of sub-probe propulsion systems will be needed to refine this figure). The overall mass contributed by the science payload to the total that must be decelerated from the interstellar cruise velocity will be considerably more than 100 tonnes, however, as allowance must be made for the payload structural and infrastructural elements required to support, deploy, and communicate with the science probes and instruments. Based on the earlier Daedalus study, we estimate another factor of two to allow for these components. Pending the outcome of more detailed studies, it therefore appears that an overall science-related payload mass of ~200 tonnes will be required. This paper is a submission of the Project Icarus Study Group.
description: Published in Journal of the British Interplanetary Society
TMD Evolution Study of the $\cos 2 ϕ$ Azimuthal Asymmetry in Unpolarized $J/ψ$ Production at EIC
Creators: name: Bor, Jelle
name: Boer, Daniël
Publisher: name: arXiv
Year: 2022
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: Semi-inclusive $J/ψ$ production in electron-proton collisions is a promising process to study gluon transverse momentum distributions (TMDs) at the future Electron-Ion Collider. In this article, we improve on previous studies of the $\cos 2 ϕ$ azimuthal asymmetry that arises from the linear polarization of gluons inside unpolarized protons by including TMD evolution. We find that in the TMD regime the asymmetry grows monotonically with increasing transverse momentum of the outgoing $J/ψ$, in contrast to tree level calculations with Gaussian TMDs. Our predictions for the asymmetry at EIC can become very large at larger $x$, $Q$, and transverse momenta, even larger than the positivity bound. This problem stems from the very small $b$ region and implies a range of validity of TMD factorization that is more restricted than usually expected. We also include an estimate of the nonperturbative uncertainty from the large $b$ region and we conclude that it is smaller than the largest source of uncertainty, which stems from the choice of Color Octet Long-Distance Matrix Elements.
description: 15 pages, 8 figures, 2 tables, V2: affiliation and acknowledgment added, V3: comments referee implemented
Inhibitory Kinetics and Mechanism of the Low Temperature Oxidation of Coal by Polyethylene Glycol-Citric Acid
Creators: name: Wang, Kai
name: Wang, Yingjie
name: Deng, Jun
name: Zhang, Yanni
name: Ding, Jiayou
Publisher: name: Taylor & Francis
Year: 2024
Subjects: subject: Biophysics
subject: Biochemistry
subject: Pharmacology
subject: Chemical Sciences not elsewhere classified
subject: Ecology
subject: FOS: Biological sciences
subject: Biological Sciences not elsewhere classified

description: To address the issues of low inhibition rate, high cost, and insufficient research on physicochemical synergistic inhibition mechanisms, this study examined the inhibitory effect and mechanism of Polyethylene Glycol-Citric Acid (PEG-CA) on low-temperature oxidation of coal. Differential scanning calorimetry (DSC) was used to analyze the inhibition and thermal behavior at various inhibitor ratios. Fourier transform infrared spectroscopy was used to experimentally assess changes in the functional groups of the coal samples pre- and post-inhibition. Principal component analysis identified the key mechanism of PEG-CA in inhibiting the low-temperature oxidation of coal. It showed that PEG-CA increased the heat absorption of the coal and delayed the average thermal equilibrium temperature of the coal oxidation process by more than 70°C. The addition of PEG-CA increased the maximum heat absorption rate of the coal sample by 2.4 times and the activation energy of coal oxidation by 1.6–3.9 times. The primary inhibition mechanism is that PEG-CA-forming chelates with the metal ions of coal, preventing C-H bond activation and reducing the content of this functional group. Additionally, PEG-CA etherifies with the hydroxyl groups of the coal, creating relatively stable ether bonds. This study offers a cost-effective and eco-friendly solution for the coal mining industry and provides a new theoretical foundation for developing composite corrosion inhibitors and controlling spontaneous coal combustion.
Nonlinear Coarse-graining Models for 3D Printed Multi-material Biomimetic Composites
Creators: name: Saldivar, Mauricio Cruz
name: Doubrovski, Eugeni L.
name: Mirzaali, Mohammad J.
name: Zadpoor, Amir A.
Publisher: name: arXiv
Year: 2022
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: Bio-inspired composites are a great promise for mimicking the extraordinary and highly efficient properties of natural materials. Recent developments in voxel-by-voxel 3D printing have enabled extreme levels of control over the material deposition, yielding complex micro-architected materials. However, spatial complexity makes it a formidable challenge to find the optimal distribution of both hard and soft phases. To address this, a nonlinear coarse-graining approach is developed, where foam-based constitutive equations are used to predict the mechanics of biomimetic composites. The proposed approach is validated by comparing coarse-grained finite element predictions against full-field strain distributions measured using digital image correlation. To evaluate the degree of coarse-graining on model accuracy, pre-notched specimens decorated with a binarized version of a renowned painting were modeled. Subsequently, coarse-graining is used to predict the fracture behavior of bio-inspired composites incorporating complex designs, such as functional gradients and hierarchical organizations. Finally, as a showcase of the proposed approach, the inverse coarse-graining is combined with a theoretical model of bone tissue adaptation to optimize the microarchitecture of a 3D-printed femur. The predicted properties were in exceptionally good agreement with the corresponding experimental results. Therefore, the coarse-graining method allows the design of advanced architected materials with tunable and predictable properties.
description: Original article
Search for a lighter neutral custodial fiveplet scalar in the Georgi-Machacek model
Creators: name: Wang, Chu
name: Tao, Jun-Quan
name: Shahzad, M. Aamir
name: Chen, Guo-Ming
name: Gascon-Shotkin, S.
Publisher: name: arXiv
Year: 2022
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: Many researches from both the theoretical and experimental sides have been performed to search for a new Higgs Boson lighter than the 125 $GeV$ Higgs boson which was discovered at the LHC in 2012. In this paper we explore the possibility of constraining a lighter neutral custodial fiveplet scalar $H_{5}^{0}$ in the Georgi-Machacek (GM) model by the latest results of the search for a lighter Higgs boson decaying into two photons from LHC data. The custodial-singlet mass eigenstate $h$ or $H$ is considered to be the LHC observed 125 $GeV$ Higgs boson. A new set of constrained parameters that is favoured by low-mass $H_{5}^{0}$, is proposed to generate events efficiently. The production of $H_{5}^{0}$ from the scan based on the constrained parameters is compared to the latest results of the search for a lighter Higgs boson decaying into two photons by CMS Collaboration, after the theoretical constraints from GM model and the constraints from all existing relevant experimental measurements including the recent results of the Higgs boson searches from the LHC. The numerical analyses of the surviving GM parameter space are performed. The tendencies and correlations of the GM input parameters from the phenomenological studies are summarized. In addition the discovery potential of other interesting decay channels of this low-mass neutral custodial fiveplet scalar are discussed.
description: 8 pages, 5 figures, submitted to Chinese Physics C