Peer Revenue Fully funded

Papers

Fresh from arXiv, typeset properly. Highlighted words trade on the market.

Physics

Watch Physics

Thursday 10 September

Geophysics

Ensemble Forecast Updates without Model Re-integration Based on Ultra-rapid Data Assimilation: Idealized Experiments with a Heavy Rainfall Case

Fumitoshi Kawasaki, Kenta Kurosawa, Atsushi Okazaki et al. (+1 more)

Observations at high frequency have become dramatically more abundant with recent technological advances. Ultra-rapid data assimilation (URDA) has been proposed to exploit them, frequently updating ensemble forecasts at lower cost without re-integrating the forecast model. In this study, we examine the applicability of URDA to a realistic numerical weather prediction (NWP). Specifically, we conducted idealized experiments for the heavy rainfall event of August 2021, using the regional atmospheric model Scalable Computing for Advanced Library and Environment (SCALE-RM). In the experiments, pseudo-observations emulating the Automated Meteorological Data Acquisition System (AMeDAS) were assumed to become available every 10 min. The results show that the threat score for hourly precipitation is generally improved in the forecasts updated by URDA relative to the pre-existing baseline forecasts, through the ensemble-based error covariance. Furthermore, for sea level pressure, temperature, relative humidity, and winds, the root mean square error of the URDA-updated forecasts is reduced relative to that of the baseline forecasts as the forecasts are successively updated by assimilating additional observations. These results indicate the potential of URDA to operate effectively with a realistic NWP model.
Read the full abstract

All authors Fumitoshi Kawasaki, Kenta Kurosawa, Atsushi Okazaki, Shunji Kotsuki

Optics

Inverse reconstruction of dissipative Kerr soliton interactions

Carlo Silvestri, Panayotis G. Kevrekidis, Stephane Coen et al. (+2 more)

We reconstruct the pairwise interaction potential between dissipative Kerr solitons from the linear stability spectrum of a perfect soliton crystal solution of the Lugiato–Lefever equation. The solitons form an overdamped lattice whose positional eigenvalues encode the pairwise-force derivative, mirroring the extraction of microscopic interactions from phonon or relaxation spectra in condensed-matter systems. The method extends beyond quadratic dispersion and assumes no functional form for the interaction. Our theory predicts a novel state -the soft soliton crystal- which has vanishing stiffness and a diverging positional relaxation time, and also explains experimentally observed soliton steps as arising from a sign reversal of the pairwise-force derivative.
Read the full abstract

All authors Carlo Silvestri, Panayotis G. Kevrekidis, Stephane Coen, C. Martijn de Sterke, Antoine F. J. Runge

Quantum Physics

Sparse-Blossom Decoding in $o(1)$ Time

Ryo Mikami and Hayata Yamasaki

Matching-based decoding is widely used in quantum error correction, and accelerating it is key to enabling fast and scalable fault-tolerant quantum computation. Minimum-weight perfect matching (MWPM) decoding provides rigorous guarantees for error suppression, while sparse blossom enables its practical implementation at modest problem sizes. However, the runtime of existing sparse-blossom implementations unavoidably increases with problem size, motivating a rigorous parallelization framework that guarantees correctness and a runtime shorter than the syndrome-extraction timescale. Here, we present such a framework and prove that the resulting parallel sparse-blossom algorithm produces the same correction as the original, non-parallel sparse blossom. For the rotated surface code with code distance $d$ and physical error rates below a finite threshold, we prove that the average parallel runtime of decoding for $O(d)$ rounds of syndrome extraction is upper bounded by a quasi-polylogarithmic function of $d$. For a $d$-round decoding window, this implies that the average parallel runtime per round is $o(1)$. We also perform numerical simulation to identify conditions under which the parallel runtime per round decreases with increasing code distance. These results suggest that increasing code distance need not lead to longer parallel decoding times, providing a foundation for scalable parallel matching-based decoding.
Read the full abstract

Strongly Correlated Electrons

Geometric Approach to the High-Throughput Identification of Honeycomb Materials

Lex M. Rouquette and Alannah M. Hallas

The honeycomb lattice is an iconic structural motif in condensed matter physics. However, emerging theoretical models require the identification of new honeycomb lattice materials with strict specification on their structural, magnetic, and electronic characteristics. In this work, we introduce a filtering algorithm using simple geometric arguments to detect materials with honeycomb structural motifs. We classify four unique categories of lattices: conventional honeycombs, hyperhoneycombs, staircase or zigzag honeycombs, and fully 3D honeycombs. We also identify several distortion motifs in the conventional honeycomb set: elongated, sheared, and buckled honeycombs. We describe several screening criteria for further analysis of honeycomb systems, specifically the quantification of exfoliability in 2D materials, the identification of magnetic honeycombs, and a density-of-states peak quality metric for identification of electronic instabilities. The database containing the results of the filters and subsequent analysis is a useful tool for identifying novel materials for targeted physical phenomena for experimental characterization.
Read the full abstract

Quantum Physics

Keyless secrecy against bounded adversaries

Anne Broadbent, Upendra Kapshikar and Denis Rochette

We introduce a keyless coding/cryptographic primitive that asks for two guarantees at once: the receiver is never fooled into accepting a message other than the one sent, and the adversary learns nothing about the message unless the receiver aborts. Neither the sender nor the receiver holds a secret key, and no computational hardness is assumed. The only restriction is on the adversary's online computation: the receiver aborts if nothing arrives by a fixed deadline, so the adversary must forward something before it, and her map in that window is computed by a circuit of size (or depth) at most $p$; before and after, she is unbounded. For every polynomial $p$ we construct such an efficient quantum scheme, encoding $k$-bit messages into $n = O(k)$ qubits with circuits of size $\mathrm{poly}(n,p)$. No classical scheme achieves this type of everlasting security, at any choice of parameters. Our techniques also resolve open questions about universal tamper detection against families restricted in cardinality rather than in circuit size. We settle a question of Broadbent, Kapshikar and Rochette on relaxed tamper detection. As a corollary, we obtain the first efficient non-malleable code secure against global quantum tampering, with no split-state restriction, whereas the current constructions in the literature require the codeword to be split into non-communicating shares.
Read the full abstract

Earth and Planetary Astrophysics

OSIRIS-REx Returned a Pristine Sample of Asteroid Bennu: Takeaways from the Mission's Contamination Control and Knowledge Program

Jason P. Dworkin, Scott A. Sandford, Nicole G. Lunning et al. (+81 more)

NASA's OSIRIS-REx mission had the objective of delivering a pristine sample from asteroid (101955) Bennu to Earth for scientific analysis–where "pristine" signifies the absence of foreign materials that could affect sample measurements. OSIRIS-REx returned 121.6 g of regolith in September 2023; this study documents the systematic investigation of suspected contaminants encountered during the mission's sample analysis phase. Most suspected contaminants did not originate from the spacecraft or sample curation. Some were introduced during laboratory analyses, reinforcing the importance of procedural blanks and a strategic approach to sharing samples across laboratories with different analytical targets. Several suspected contaminants, such as phosphate and sodium fluoride particles, were ultimately identified as indigenous to Bennu, highlighting the critical role of contamination knowledge in preventing the dismissal of valuable scientific data. We find that the returned sample meets the definition of pristine, except for an isolated 1.24% (by mass) that escaped the sample container and was thereby contaminated with spacecraft particulates. These findings demonstrate the effectiveness of systematically applied contamination science and engineering practices and provide lessons and approaches to help maximize the scientific integrity of future planetary sample return missions.
Read the full abstract

All authors Jason P. Dworkin, Scott A. Sandford, Nicole G. Lunning, Kevin Righter, Charles C. Lorentson, Daniel P. Glavin, Kathie L. Thomas-Keprta, Loan Le, Catherine M. Corrigan, Timothy J. McCoy, Edward B. Bierhaus, Jose C. Aponte, Angel Mojarro, Hannah L. McLain, Eric T. Parker, Denise K. Buckner, Frédéric Seguin, Radford L. Perry, Heather V. Graham, Havishk Tripathi, Pierre Haenecour, Piers Koefoed, Kun Wang, Cody Schultz, Takahiro Hiroi, Ralph E. Milliken, Simon J. Clemett, Bumsoo Kim, Christopher J. Snead, Eve L. Berger, Michael Liss, Jessica J. Barnes, Sandra Freund, Zoe A. Wilson, Ryan D. Dubisher, Natasha V. Almeida, Kimberly K. Allums, Erika H. Blumenfeld, Joseph E. Aebersold, Rachel C. Funk, Carla P. Gonzales, Julia L. Plummer, Maritza Montoya, Daniel J. Rohmer, Erika V. Rivera, Jannatul Ferdous, Gabriel C. Garcia, Melissa Rodriguez, Jose L. Ponce, Ronald Bastien, Wayland D. Connelly, Jemma Davidson, Marghaleray Amini, Vivian Lai, Dominique Weis, Josh Wimpenny, Jan Render, Gregory A. Brennecka, Yoshihiro Furukawa, Toshiki Koga, Yoshinori Takano, Hiroshi Naraoka, Yasuhiro Oba, Kenneth J. Domanik, Yao-Jen Chang, Zoe Zeszut, Thomas J. Zega, George D. Cody, Conel M. O'D. Alexander, Ian A. Franchi, Monica M. Grady, Danielle N. Simkus, Jamie E. Elsila, Philippe Schmitt-Kopplin, Allison A. Baczynski, Katherine H. Freeman, Amy E. Hofmann, Aaron S. Burton, Lindsay P. Keller, Sara S. Russell, Anjani T. Polit, Francis M. McCubbin, Harold C. Connolly Jr., Dante S. Lauretta

Chaotic Dynamics

Variability in a Model of Divergent and Convergent Coupled Ice Streams: Synchronisation, Transients and Chaos

Joshua Grimstead, Peter Ashwin and Tanja I. Schindler

Fast-flowing glaciers, known as ice streams, control the majority of ice sheet mass loss due to thermomechanical coupling at their base, which can induce basal lubrication and highly variable flow. Even quite simple models can show `binge-purge' oscillations. Recent work has highlighted that coupling between divergent ice streams can also give rise to chaotic variability. In this paper, we return to a model of ice streams with a divergent coupling to identify and correct some physical inconsistencies, most notably a global volume conservation error. We propose and validate a revised Divergent Coupling (DC) model that ensures rigorous mass balance. Bifurcation analysis and Poincaré sections reveal previously unidentified complex frequency-locking (Arnold tongues), a period-adding cascade and chaos associated with torus breakdown. We also consider an equivalent model with a Convergent Coupling (CC), where we find no evidence of chaotic variability. These findings suggest the importance of specific topologies on ice stream variability.
Read the full abstract

Earth and Planetary Astrophysics

Steepening Optical Slopes in Exoplanet Transmission Spectra with Charged Hazes

Masayuki Inai, Kazumasa Ohno and Shota Notsu

Observations of exoplanetary atmospheres have revealed the ubiquity of aerosols, yet their microphysics remain largely uncertain. Haze charging is a key microphysical process in aerosol-rich Solar System atmospheres, but it has been ignored in exoplanetary haze models. Here we develop a microphysical framework that includes haze charging for exoplanet atmospheres and investigate its effects on transmission spectra. Electrostatic repulsion suppresses coagulation, maintaining smaller particle radii and higher mixing ratios in the upper atmospheres. We find that particle charging steepens the optical spectral slopes when vertical mixing is weak. This behavior arises from the combination of reduced particle sizes and a steepened vertical gradient in haze opacity. Furthermore, we find distinct spectral responses to charging for different haze analogs, owing to the different contributions of scattering and absorption. For absorption-dominated materials such as soot, particle-size reduction has little impact on opacity profiles, leading to only minor charging-induced spectral changes. By contrast, scattering-dominated materials such as tholin and diamond show a stronger spectral signature of particle charging because of the strong dependence of scattering opacity on particle size. While previous studies have invoked haze formation under vigorous vertical mixing as a mechanism for producing super-Rayleigh optical slopes, we demonstrate that highly charged scattering haze can produce such slopes even under weak-to-moderate vertical mixing. Our results highlight haze charging as a previously neglected microphysical process that can affect particle growth and leave observable signatures in transmission spectra, providing a quantitative framework for assessing atmospheric electrical conditions.
Read the full abstract

Accelerator Physics

Continuous-Wave Operation at 30 MV/m of a Superconducting Radio-Frequency Gun Cryomodule with an Exchangeable Cathode Plug

T. Konomi, T. Xu, Y. Choi et al. (+30 more)

A prototype 185.7 MHz superconducting radio-frequency (SRF) electron gun cryomodule has been developed for the proposed LCLS-II-HE Low Emittance Injector at SLAC. It has an in-situ ultra-high-vacuum exchangeable cathode plug system compatible with semiconductor photocathodes. With a copper plug, the gun achieved continuous-wave RF operation at a cathode field of 30 MV/m. No measurable degradation was observed after plug removal and reinsertion with the cavity at 4.4 K. This result is a significant improvement over past continuous-wave SRF gun systems with exchangeable plugs.
Read the full abstract

All authors T. Konomi, T. Xu, Y. Choi, K. Elliott, B. Gower, B. Tousignant, J. Wenstrom, A. Taylor, C. Compton, W. Chang, X. Du, W. Hartung, S. H. Kim, S. Miller, D. Morris, M. Patil, L. Popielarski, J. Wei, Z. Yin, J. Smedley, J. Maniscalco, C. Adolphsen, M. Murphy, D. A. Gonnella, M. P. Kelly, T. Petersen, A. Arnold, S. Gatzmaga, R. Steinbrück, P. Murcek, R. Xiang, J. Teichert, J. Lewellen

Fluid Dynamics

Spreading dynamics of a drop of yield-stress fluid subject to vertical oscillations

Alice Woodbridge, Claudio P. Fonte and Anne Juel

The measurement of rheological properties from non-idealised flows is routinely used to characterise yield-stress materials. We extend the canonical slump test, which evaluates yield stress based on the spread of a large drop under gravity, by subjecting such a drop to vertical oscillation of its substrate. We test this flow configuration by direct comparison between experiments and numerical simulations of the time-dependent Cauchy equations coupled to the Saramito-Herschel-Bulkley (SHB) constitutive model. This provides a sensitive test of the SHB model near yield because the vibrated drop can releases stress exceeding the yield stress by adjusting its shape as the forcing acceleration is increased, and thus, remains close to the yield threshold for all forcing. We find that the SHB model systematically underpredicts the amplitude of the viscoelastic oscillatory response of the drop to forcing by a factor of five. However, spreading can be captured numerically by selecting a solvent viscosity that represents the appropriate post-yield rheology of the material at the expense of matching sub-yield properties. This highlights a fundamental challenge in simulating flows in which yielded and unyielded material coexist, such as those encountered in proto-rheological tests. We establish the vibrated drop as a powerful proto-rheological configuration for estimating the yield stress across drops of different rheology, size and shape, by establishing a proportional relationship between the threshold acceleration required to induce spreading relative to gravity and the yield number, the ratio of yield stress to gravitational stress acting at the centre of mass of the drop.
Read the full abstract

Atmospheric and Oceanic Physics

WIND-Bench: A Benchmark Dataset for In-Situ Near-Surface Wind Speed Observations Across the Conterminous United States

Kyla Bazlen, Grant Buster, Brandon Benton et al. (+5 more)

Accurate wind forecasts are essential for operational decision-making and public safety, yet forecasts tend to miss near-surface high wind speeds in complex terrain. In response, advances in machine learning (ML) weather prediction methods have demonstrated the ability to improve forecast skill beyond traditional numerical weather prediction (NWP) models. However, the absence of a benchmark dataset to evaluate NWP and ML models with sufficient, quality-controlled wind speed observations in complex terrain poses challenges to the development and intercomparison of high-quality surface wind forecasts across the Conterminous United States (CONUS). We develop the Wind IN-situ Data Benchmark (WIND-Bench), a benchmark dataset from in-situ observations in the Meteorological Assimilation Data Ingest System (MADIS) observational network. WIND-Bench integrates multiple sensor networks with quality control that distinguishes sensor failures from high-wind conditions, using a framework that validates observations against forecasts from the National Oceanic and Atmospheric Administration (NOAA) High-Resolution Rapid Refresh (HRRR) model. WIND-Bench provides a standardized benchmark for evaluating ML and NWP models and for quantifying forecast skill, accelerating the development, evaluation, and operational deployment of skilled near-surface wind forecasts.
Read the full abstract

All authors Kyla Bazlen, Grant Buster, Brandon Benton, Lauren North, Ansley Baring, David D. Turner, Emily Wells, Laura Vimmerstedt

General Relativity and Quantum Cosmology

Classical and quantum perspectives on temperature in accelerated frames

Babak Vakili

We study the notion of temperature in uniformly accelerated frames within a relativistic thermodynamic framework. Considering a perfect fluid at rest in a non-inertial (Rindler) frame, we derive the condition for thermal equilibrium from energy–momentum conservation. This leads to a position-dependent temperature profile consistent with the Tolman–Ehrenfest relation. We emphasize that this temperature characterizes the local thermodynamic equilibrium of the fluid in the accelerated frame and does not arise from a transformation law between different observers. The physical interpretation of the result and its relation to acceleration-induced effects are briefly discussed.
Read the full abstract

Quantum Physics

Learning Sparse Quantum States

Aniruddha Sen

We study the problem of tomography for $k$-sparse quantum states. In contrast to classical distribution learning, where tight sample and time complexity bounds in terms of support size are well understood, no non-trivial bounds were previously shown for this problem. We give the first near optimal algorithm for learning $n$-qubit $k$-sparse pure quantum states, obtaining fidelity at least $1-\varepsilon$ with high probability using $\tilde{O}(k/\varepsilon)$ copies of the state and $\tilde{O}(kn/\varepsilon)$ time. Both bounds are optimal up to polylogarithmic factors. As an implication, we also obtain an algorithm with near optimal $\tilde{O}(kr/\varepsilon)$ sample complexity for learning $k$-sparse rank-$r$ mixed states, via the random purification channel technique. Obtaining time complexity nearly matching the sample complexity, for $r>1$, remains an important open question.
Read the full abstract

Solar and Stellar Astrophysics

Plasma Heating and Energization in Hot-Onset Flare Precursor Events

H. Da, J. F. Drake and M. Swisdak

Recent observations of solar flares have revealed a distinct 'hot onset' phase preceding the impulsive phase, characterized by elevated plasma temperature (>10 MK), a steady increase in emission measure, and the absence of detectable nonthermal emission. The standard flare model attributes the formation of hot flare plasma to chromospheric evaporation driven by energy deposition from nonthermal electrons, and therefore does not naturally explain why thermal heating precedes nonthermal emission. Motivated by recent observations of guide-field evolution in two-ribbon flares and by large-scale MHD simulations, we investigate hot-onset energization using simulations of magnetic reconnection with the kinetic macroscale model kglobal initialized with a spatially non-uniform guide field. Because the efficiency of electron non-thermal energy production from Fermi acceleration decreases with guide-field strength, the evolving guide field produces two distinct energization regimes. During the initial high-guide-field phase, the bulk electron temperature rises to approximately twice its initial value, while non-thermal particle production remains weak. Upon entering the low-guide-field regime, energetic particle production is significantly enhanced, with the population of high-energy electrons growing rapidly. These findings provide a self-consistent physical explanation for the hot onset, demonstrating that the macroscopic evolution of the guide field naturally bridges the hot-onset and impulsive phases of solar flares without requiring a separate trigger mechanism.
Read the full abstract

Optics

Frequency-Multiplexed Photonic Reservoir Computing with a Synchronously Pulse-Driven Optical Cavity

Amir Arsalan Arabieh, Simon-Pierre Gorza and Serge Massar

In this work, we introduce a new platform for frequency-multiplexed reservoir computing based on an optical cavity driven by pulses whose repetition period is matched to the cavity roundtrip time. The input symbols are encoded by modulating either the amplitude or the phase of the driving pulses. Our numerical results show that the proposed synchronously pulse-driven cavity operates in a weakly nonlinear regime under anomalous dispersion, while under normal dispersion it exhibits optical bistability with a high-peak-power upper-branch state. By isolating the key physical parameters, we quantify their individual contributions to information-processing performance. We further show that spectral symmetry breaking induced by third-order dispersion and Raman scattering almost doubles the information-processing capacity. Finally, we demonstrate that modulation-induced branch switching within the bistable regime limits stable reservoir operation.
Read the full abstract

Quantum Physics

Path-Degenerate Quantum Interferometry for Loss Resilience in Gravitational-Wave Detectors

Jonas Rittmeyer, Niels Boettner, Farid Khalili et al. (+2 more)

Optical decoherence degrades quantum correlations in squeezed states of light, severely limiting the quantum-nondemolition (QND) sensitivity of gravitational-wave detectors. Here, we propose the path-degenerate quantum interferometry scheme that obviates the need for entire optical subsystems—including additional filter cavities, auxiliary parametric amplifiers, and Faraday isolators—thereby drastically reducing spatial mode mismatches while inherently integrating variational output, a long-standing theoretical proposal to further deepen the QND regime. We experimentally demonstrate a core aspect of this scheme, achieving a shot-noise-preserving signal enhancement that directly counteracts the detrimental effects of readout loss. By delivering an improved signal-to-quantum-noise ratio solely through the consolidation and reduction of currently considered optical subsystems, our approach offers a highly optimized route toward enhanced quantum-noise reduction in upcoming LIGO upgrades and next-generation gravitational-wave observatories.
Read the full abstract

All authors Jonas Rittmeyer, Niels Boettner, Farid Khalili, Mikhail Korobko, Roman Schnabel

Astrophysics of Galaxies

NOEMA probes the [CII] and dust content in a 2175Å UV Bump Galaxy at $z=7.1$

Katherine Ormerod, Renske Smit, Joris Witstok et al. (+5 more)

The detection of the $2175$Å UV bump at $z>6$ challenges existing models of dust formation, suggesting rapid formation of small carbonaceous dust grains within the first billion years of cosmic time. We present the results of the first direct attempt at linking far-infrared (FIR) observations to the UV bump within the Epoch of Reionisation (EoR), through NOEMA observations of GNWY-7379420231 at $z=7.108$, a galaxy exhibiting the strongest known UV bump feature at $z>4$. We detect the [CII] 158$\mu$m emission line at 5.1$\sigma$ at $z_\mathrm{[CII]} = 7.1078 \pm 0.0005$, in excellent agreement with the redshift derived from the [OIII] $\lambda 5007$Å line. The {\cii} luminosity implies $\mathrm{SFR}_\mathrm{[CII]}=16.2^{+5.8}_{-5.5}M_\odot \mathrm{yr}^{-1}$, consistent with short timescale SFR tracers such as dust corrected $\mathrm{SFR}_\mathrm{H\alpha}=18.0\pm3.9 M_\odot \mathrm{yr}^{-1}$ and $\mathrm{SFR}_\mathrm{10~Myr}=20.5^{+3.8}_{-5.0}M_\odot \mathrm{yr}^{-1}$ from SED fitting. The dust continuum is not detected suggesting an obscured SFR of $\mathrm{SFR}_\mathrm{IR} < 32 ~M_\odot \mathrm{yr}^{-1}$ and a dust mass of $M_\mathrm{d} < 5.3\times10^6 ~M_\odot$ $(M_\mathrm{d}/M_\star<2\%)$. Finally, the [CII]-derived dynamical mass of $\log_{10}(M_\mathrm{dyn}/M_\odot)=8.95^{+0.51}_{-0.66}$ and stellar mass of $\log _{10}\left(\mathrm{M}_{\star} / \mathrm{M}_{\odot}\right) = 8.39_{-0.09}^{+0.13}$ suggest a gas-rich moderately massive galaxy. Taken together these results rule out GNWY-7379420231 being a heavily dust obscured or massive galaxy, but rather a `normal' EoR galaxy with a recent upturn in star-formation. Our results suggest efficient shattering of larger dust grains in the diffuse, turbulent ISM and/or fortunate line of sight alignment are needed to explain the UV bump properties of GNWY-7379420231.
Read the full abstract

All authors Katherine Ormerod, Renske Smit, Joris Witstok, Anna de Graaff, Michael V. Maseda, Irene Shivaei, Andrew J. Bunker, Gareth C. Jones

Quantum Physics

Ab initio multichannel calculation of the Bethe surface and Compton defects for molecular hydrogen

Hakon Volkmann and Alejandro Saenz

A correlated multichannel computation of the generalized oscillator-strength density for electrons scattering off randomly oriented molecular hydrogen at the internuclear separation of 1.4 $a_0$ is being presented. The numerical procedure features a novel free-boundary method based on configuration interaction of ionic orbitals expanded in B splines using prolate-spheroidal coordinates. Satisfactory agreement between the present and both experimental as well as other theoretical results has been found, thus providing a view on the Bethe surface for energy transfers up to of 558 eV. The systematic and robust convergence behavior of the method further allowed for assessing the validity of the binary-encounter approximation, providing a confirmation of experimentally determined Compton defects for H$_2$ using a single consistent theoretical description. Overall, the present findings are expected to be helpful for calculating highly accurate energy-loss spectra for fast electrons passing through and ionizing molecular hydrogen gas or its isotopologues.
Read the full abstract

Strongly Correlated Electrons

Selective coupling of coherent phonons to intertwined charge-orbital and magnetic orders in doped manganites

X. Liu, M. Sander, S.-W. Huang et al. (+15 more)

Strongly correlated materials feature technologically relevant functionalities such as high-temperature superconductivity and colossal magnetoresistance, which emerges from the competition and coexistence of electronic and magnetic phases. Uncovering the microscopic interactions underlying these phenomena remains challenging because spin, orbital, charge, and lattice degrees of freedom are inherently intertwined. Here, by combining time-resolved X-ray diffraction and polarization-resolved ultrafast optical reflectivity in La1/4Pr3/8Ca3/8MnO3, we reveal that coherent phonon modes can selectively track different ordered phases: the in-plane phonon response is predominantly sensitive to charge/orbital order, and the c-axis phonon response is sensitive to magnetic order. Moreover, a ferromagnetic-related hysteresis emerges even when solely probing the charge/orbital-ordered phase, indicating a strong microscopic coupling between the spatially separated charge/orbital-ordered and ferromagnetic-ordered phases. These results demonstrate that coherent phonons provide a direct time-domain route to disentangle intertwined electronic and magnetic dynamics in coupled phases.
Read the full abstract

All authors X. Liu, M. Sander, S.-W. Huang, S. Zerdane, A. Caviezel, M. Rössle, J. Lu, D. Babich, S. Shin, E. Pomjakushina, P. Marsik, L. Wang, S. W. Cheong, C. Jia, P. Beaud, H.T. Lemke, U. Staub, R. Mankowsky

Materials Science

Pseudo-hybrid density functional ACBN0 for Hubbard $U$ correction in a numeric atom-centered orbital basis

Svetlana A. Artiukova, Ilia M. Odud and Sergey V. Levchenko

We present a formulation and implementation of the Agapito-Curtarolo-Buongiorno Nardelli (ACBN0) pseudo-hybrid density functional in a numeric atom-centered orbital basis. The method is realized in the all-electron, full-potential electronic-structure package FHI-aims. The implementation uses a Löwdin-orthogonalized projector, which improved the stability of the self-consistent ACBN0 iterations for the tested systems. For a benchmark set of materials including metal oxides and nitrides, ACBN0 with the fully localized limit (FLL) as the double-counting treatment reduces the aggregate band gap errors relative to the Perdew-Burke-Ernzerhof (PBE) and strongly constrained and appropriately normed (SCAN) functionals, reaching an accuracy comparable to the Heyd-Scuseria-Ernzerhof functional (HSE06). The computational cost of a single ACBN0 self-consistent-field iteration is comparable to that of the parent functional and substantially lower than that of HSE06. The applicability of the localizedbasis implementation to low-dimensional systems is demonstrated by calculations of adsorption and the oxygen evolution reaction (OER) overpotential on a $\beta$-NiOOH(001) surface. On structures relaxed with regularized SCAN (rSCAN), single-point ACBN0 calculations based on rSCAN (ACBN0@rSCAN) with the "tight" numerical settings reduce the mean absolute deviation of the reaction-step energies from HSE06 and shift the estimated overpotential toward the HSE06 and Perdew-Burke-Ernzerhof hybrid (PBE0) reference results.
Read the full abstract

General Relativity and Quantum Cosmology

Distinguishing Dymnikova and Schwarzschild Black Holes through Gravitational Lensing with EFT-Corrected Photon Propagation

Takamasa Kanai

We investigate whether a Dymnikova regular black hole can be observationally distinguished from a Schwarzschild black hole through strong gravitational lensing, taking into account effective field theory (EFT) corrections to photon propagation. We derive the modified photon propagation law induced by non-minimal couplings between the electromagnetic field and spacetime curvature and analyze the resulting photon trajectories in the Dymnikova spacetime. Within the strong deflection limit, we derive the EFT corrections to the photon sphere and the strong-deflection coefficients characterizing the logarithmically divergent behavior of the deflection angle. Although the EFT corrections are parametrically small, their effects can become relevant in the strong-deflection regime, where the deflection angle is highly sensitive to photon propagation near the critical orbit. We evaluate the strong-deflection observables for representative values of the Dymnikova parameter $\ell$ and compare them with the corresponding Schwarzschild results. We find that EFT corrections to photon propagation leave characteristic imprints on the strong-lensing observables. Furthermore, the contribution of the EFT corrections becomes more pronounced as the Dymnikova parameter $\ell$ approaches its critical value, indicating that the near-critical regime provides a particularly sensitive setting in which curvature-dependent corrections to photon propagation may affect gravitational lensing. These results suggest that strong gravitational lensing, together with EFT-induced modifications of photon propagation, may provide a means of distinguishing Dymnikova regular black holes from Schwarzschild black holes.
Read the full abstract

Materials Science

Different critical exponents on two sides of the magnetic transition in two dimensions

P. Biswal, Ruma Khatun, G. Tripathy et al. (+2 more)

The possibility of different critical exponents on two sides of a magnetic transition has been theoretically predicted [PRB 13, 2222 (1976), PRL 115, 200601 (2015)] and experimentally realized [PRL 128, 015703 (2022)] in three-dimensional systems. However, the emergence of such a scenario in two dimensions is not yet established. Here, we report distinct two-dimensional (2D) critical exponents below and above the magnetic transition temperature (TC) through critical scaling analysis in a quasi-2D non-centrosymmetric, Dzyaloshinskii-Moriya interaction (DMI) active hybrid perovskite (C7H9NBr)2CuBr4. The system exhibits critical exponents of 2D Ising-type below TC and 2D XY-type above TC . In contrast, isostructural Cl and centrosymmetric Br analogs, in which the DMI effect is expected to be weaker, exhibit symmetric 2D critical behavior. These results highlight the crucial role of DMI in (C7H9NBr)2CuBr4 as a symmetry-breaking perturbation that alters the magnetic critical behavior differently above and below TC . Our study is the experimental realization of hitherto unreported asymmetric 2D critical behavior in structurally flexible and dimensionally tunable hybrid perovskites.
Read the full abstract

All authors P. Biswal, Ruma Khatun, G. Tripathy, Diptikanta Swain, D. Samal

Fluid Dynamics

Transferable Low-Dimensional Representations of Aircraft Surface Fields

Francis G. VanGessel, Cashen Diniz and Mark Fuge

Analyzing flow fields on aerodynamic surfaces is critical to designing next-generation aircraft. Raw computational representations are high-dimensional and costly for complex three-dimensional bodies, while conventional low-dimensional representations apply only to the systems from which they derive. We introduce an approach that learns fluid flow representations from simple two-dimensional geometries and transfers them to complex real-world three-dimensional aircraft. Comparing the proposed Least Volume autoencoder (LVAE) to proper orthogonal decomposition (POD), we show both yield compact 28-41 dimensional representations of two-dimensional flow fields, with the nonlinear LVAE producing more accurate in-domain reconstructions at matched dimensionality. These models transfer zero-shot to three-dimensional systems, and counterintuitively the linear POD transfers more accurately than LVAE. Applied to extruded wings, POD-reconstructed lift and drag remain within 0.1% and 0.7% of true values, while transfer to complex blended wing body aircraft preserves lift and drag to within 0.3% and 0.7% without any three-dimensional training data. We further show that three-dimensional flow patterns missed by the pretrained model can be isolated to train a disentangled 3D latent space via a dual encoder-decoder transfer learning strategy, performing accurately in previously inaccessible data-scarce regimes. Using only five blended wing training cases, mean squared reconstruction error drops by 5x relative to the 2D pretrained models and 70x relative to models trained from scratch. These results establish that transfer learning from readily available two-dimensional datasets unlocks compact, interpretable representations of complex three-dimensional aircraft surface flows, enabling design insights in data-starved early phases where conventional approaches require hundreds to thousands of simulations.
Read the full abstract

Instrumentation and Detectors

Agentic TCAD Calibration Workflow for Oxide Semiconductor Transistors

Gyujun Jeong, Junmo Lee, Sungwon Cho et al. (+11 more)

Experimental TCAD calibration is essential for predictive technology modeling of emerging oxide semiconductor transistors. However, it remains time-consuming and expert dependent because of model ambiguity. Multiple physical models and parameter sets can reproduce the same measured transfer characteristics, while local fitting alone cannot uniquely identify the underlying device physics. We present the first demonstration of an agentic TCAD calibration workflow for a fabricated bottom-gate In–W–O (BG-IWO) transistor. Starting from the measured transfer curve and device information, the workflow uses measurement–TCAD residuals and local sensitivity tests to select bounded parameter corrections or evaluate additional physical models, and accept only updates that improve device metrics. The LLM agent orchestrates the workflow, while Sentaurus governs the device physics. For the 2%-W reference device, five agent-suggested updates yield a fixed calibrated model, reducing the multi-metric device objective $J$ by 14.3$\times$. Maximum $V_{\mathrm{th}}$/$I_{\mathrm{on}}$ errors are 36.1~mV/0.022 decade for varying-drain-bias tests and 46.2~mV/0.062 decade for varying-channel-length tests, demonstrating model transferability across bias and geometry rather than a local parameter fit. W-composition tests provide process-sensitive insight. This agentic workflow provides a faster route to model development for emerging device technologies.
Read the full abstract

All authors Gyujun Jeong, Junmo Lee, Sungwon Cho, Woohyun Hwang, Kwangyou Seo, Suhwan Lim, Wanki Kim, Daewon Ha, Rishi Ranade, Kihang Youn, Ram Cherukuri, Yiyi Wang, Asif Khan, Shimeng Yu

High Energy Physics (Phenomenology)

Radiative corrections to weak interaction processes

Chien-Yeah Seng

The search for physics beyond the Standard Model in low-energy weak interaction processes requires a precise knowledge of the Standard Model background at tree- and loop-level. In many such cases, radiative corrections represent one of the major sources of theory uncertainty due to the non-perturbative structures of nucleon or nuclei. In this review, I discuss several modern strategies based on dispersion relation, lattice gauge theory and nuclear many-body calculations to pin down the hadronic and nuclear uncertainties in the radiative corrections to low-energy weak interaction processes such as beta decays and parity-violating electron-nucleus scattering.
Read the full abstract

Materials Science · Cross-listed from cs.CV

Physics as the label for measuring and correcting materials reasoning in multimodal models

Hasan Kurban, Rasul Khanbayov and Mustafa Kurban

Vision-language and language models increasingly interpret materials data, yet benchmarks report that they hallucinate invalid properties and violate physical law. Evaluation matches final answers to scarce human labels, while discovery agents verify final proposals or density functional theory (DFT) execution. Neither measures the physical consistency of a model's reasoning chain. Materials data carries its own physics, making a large class of materials reasoning verifiable without annotation. We introduce MatPCR, a label-free benchmark whose programmatic oracles check diffraction geometry through Bragg's law, scale bars, spectral peaks, and Materials Project-grounded checks of near-hull stability, computed band-gap class, and net magnetization. We define the Physical-Consistency Rate over image and structure inputs; introduce Constraint-Grounded Self-Verification, an agentic loop whose gain survives self-refinement and equal-compute re-prompting controls; release an open verifier useful in distribution but near chance on all six held-out constraint types; and derive an exact identity for how oracle error displaces the reported rate.
Read the full abstract

Physics and Society · Cross-listed from cs.SI

Motifs in temporal hypergraphs

Quintino Francesco Lotito, Lorenzo Betti, Federico Battiston et al. (+1 more)

Network motifs, recurrent local patterns of interactions in graphs, provide fundamental insights on the interplay between structure and functionality in complex systems. Many real-world systems are not well represented by traditional static pairwise networks, as interactions may involve groups of nodes, occur over time, or encode directionality. In this paper, we introduce temporal motifs for hypergraphs and directed hypergraphs, extending motif analysis to timestamped many-body interactions. We formalize the corresponding mining problem, study the combinatorial structure of these motifs, and develop exact algorithms for their enumeration. In particular, we propose a dynamic programming algorithm that substantially reduces the computational cost of motif mining, achieving orders of magnitude speedups on empirical datasets. We also introduce a null model for temporal hypergraphs to assess the statistical over- and under-expression of motifs. Applying the proposed framework to real-world datasets from different domains, including face-to-face contacts, scientific collaborations, e-mail exchanges, and Bitcoin transactions, we show that temporal hypergraph motifs reveal distinct forms of local organization across systems. Finally, we demonstrate their use as an exploratory tool through focused case studies on persistent patterns in scientific collaborations and e-mail communications.
Read the full abstract

All authors Quintino Francesco Lotito, Lorenzo Betti, Federico Battiston, Giuseppe Francesco Italiano

High Energy Astrophysical Phenomena

Hidden structures in the UHE sky: unveiling potential cosmic-ray sources via spectral signatures

Mateus Zeferino Rennó and Cainã de Oliveira

The search for the origin of ultrahigh-energy cosmic rays (UHECRs) typically relies on identifying directional excesses in the particle flux. While this approach is well established, it cannot detect localized spectral features, which could provide constraints on the sources of UHECRs if measured. In this work, we propose extending directional searches through two complementary energy-weighted metrics: the accumulated energy $U$ and the local average energy per particle $\mu_E$. We demonstrate that $U$ inherently amplifies the statistical significance of sources with high-energy tails, while $\mu_E$ provides a distinct probe for direction-dependent spectra. To assess the statistical significance of these metrics, we derive a generalization of the Li-Ma significance formula for continuous energy variables. Using a maximum-likelihood analysis within an exploratory Monte-Carlo model, we show that these variables can enhance discovery potential by amplifying localized excesses and identifying hard-spectrum regions that are not apparent in standard particle-flux maps, thereby providing a comprehensive probe of potential UHECR sources. Furthermore, $\mu_E$ variations associated with localized excesses are smoothed into minor perturbations when the spectrum is integrated over right-ascension or declination bands. Consequently, the presence of small- or intermediate-scale regions with distinct spectral shapes remains consistent with the absence of declination-band spectral variations recently reported by the Pierre Auger Collaboration.
Read the full abstract

Quantum Physics

Parallel Circuit Execution for Scalable Quantum Computation

Avimita Chatterjee, W. Michael Brown, Siyuan Niu et al. (+2 more)

Today's quantum processors have tens to hundreds of physical qubits, but reliable execution of arbitrary circuits remains limited to fewer than 30 entangled qubits across hardware modalities. Building upon prior work, we introduce an error- and topology-aware method for mapping multiple independent circuits onto disjoint regions of a single large-scale QPU for parallel circuit execution. For applications with many similarly sized circuits, such as observable estimation for Hamiltonian simulation, this approach can reduce billed QPU execution time, with ideal speedup proportional to the number of usable partitions. We demonstrate the approach on IBM's 156-qubit ibm_boston processor using standard QED-C benchmark and Hamiltonian-based observable-estimation workloads. Compared with standard sequential execution, parallel execution reduces billed execution time by 3.5-5.5x while retaining 83-92% of the sequential fidelity. We further evaluate the scaling of parallel circuit execution using GPU-accelerated classical simulation, distributing measurement circuits across GPUs via MPI. Using CUDA-Q on the NERSC Perlmutter system, we achieve up to 13.8x speedup on 16 GPUs (86% parallel efficiency) for an H2 electronic-structure simulation, with scaling evaluated across multiple Hamiltonians and circuit counts. These results provide an indication of the performance ceiling that parallel execution on future quantum hardware may eventually approach. Both execution modes are implemented as a runtime option within the QED-C Application-Oriented Benchmark suite. Together, the results show that circuit-level parallelism can reduce execution cost on current quantum hardware and simulation time on GPU clusters, with the potential for greater benefits as device quality and qubit counts increase.
Read the full abstract

All authors Avimita Chatterjee, W. Michael Brown, Siyuan Niu, Wibe Albert de Jong, Thomas Lubinski

Materials Science

Functionalization-Driven Charge Redistribution Enabling Ultra-High-Capacity V2B MBene Anode for Li/Na ion batteries: A First-Principles study

Shaiokh Bin Abi and Ahmed Zubair

Amid increasing global demand for clean, sustainable energy, the search for novel electrode materials has emerged as a crucial link to advancing future energy storage technologies. Here, we explored the potential of N-functionalized 2D MBene V2BN2 as anode materials for Li- and Na-ion batteries using first-principles calculations. Phonon dispersion and ab initio molecular dynamics calculations were employed to assess the dynamic and thermal stability of the material. The intrinsic metallic properties of V2BN2 were revealed through electronic band structures and density of states analyses. Importantly, Bader charge analysis demonstrates substantial charge redistribution upon Li/Na adsorption, leading to stronger ion-substrate interactions compared to the pristine counterpart. This redistribution plays a decisive role in enhancing Li/Na ion adsorption and stabilizing ion accommodation. Furthermore, owing to favorable multilayer adsorption of Li and Na ions, V2BN2 exhibited high theoretical specific capacities of 1524 and 762 mAh/g, as well as low open circuit voltages of 0.73 and 0.23 V for Li and Na, respectively. In addition, the energy barriers were calculated to be 0.49 and 0.29 eV for Li- and Na-ion transport, respectively, indicating rapid ion transport and excellent rate capability. These results indicate that V2BN2 holds significant potential as an anode material for next-generation rechargeable ion batteries.
Read the full abstract