Mesoscale and Nanoscale Physics
Polarization engineered all 2D Graphene/Ferroelectric hybrid for persistence-free photoresponse
Navkiranjot Kaur Gill, Shaili Sett, Saloni Kakkar et al. (+3 more)
Graphene-based van der Waals hybrid photodetectors typically work on trap-mediated photogating mechanism, exhibiting high sensitivity, but under-perform in the fast detection of repetitive optical signals. Designing photodetectors that are simultaneously fast and highly sensitive has therefore remained difficult. In this work, we realize both attributes by integrating atomically thin sliding ferroelectrics in the design architecture, thereby uniting semiconducting properties with intrinsic polarization fields capable of efficiently governing interfacial photocarrier dynamics. We report a
bilayer graphene-
bilayer MoS2 (with MoS2 in a rhombohedrally stacked (3R) configuration) van der Waals photodetector with edge-contacted dual-gated field-effect transistor architecture. The photo-induced modulation in spontaneous out-of-plane polarization of 3R-MoS2 and selective confinement of charge carriers in
bilayer graphene under an out-of-plane displacement field results in a tunable persistence-free photoresponse. Here, the photoinduced polarization change in 3R-MoS2 produces an optically controlled gating effect that alters the electrostatic environment of
bilayer graphene, resulting in a temperature-independent photoresponse with rapid response times of the order of 10's of milliseconds (limited by the measurement instrument). We demonstrate reproducible detection of optical signals and examine the
photon-counting resolution of this structure in high-sensitivity regimes, where we determine its internal
quantum efficiency to be 10 percent with minimum detectable
photon number of 31 in single shot measurements. This work highlights the functionality of 3R-MoS2 in manipulating the interfacial charge dynamics and establishes the hybrid of
graphene and ferroelectric 3R-MoS2 as a promising platform for ultra-sensitive optoelectronic devices.
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All authors Navkiranjot Kaur Gill, Shaili Sett, Saloni Kakkar, Kenji Watanabe, Takashi Taniguchi, Arindam Ghosh
General Relativity and Quantum Cosmology
Correlated parity violation in gravity and electromagnetism from five-dimensional spacetime
Haomin Rao, Yunlong Zheng, Qi-Zhe Hou et al. (+2 more)
Parity violation in the gravitational and electromagnetic sectors has been extensively investigated, yet the two are conventionally treated as independent phenomena. This separation, however, may be a four-dimensional prejudice. In higher-dimensional spacetime,
gravity and electromagnetism may share a common
geometric origin—and so, perhaps, does their parity violation. In this paper, we pursue this idea by constructing parity-violating Kaluza-Klein models in both Riemannian and teleparallel geometries. In Riemannian geometry, the simplest five-dimensional parity-violating term reduces to several complicated four-dimensional terms, including the familiar gravitational Chern-Simons term, which suffers from a ghost instability. In teleparallel geometry, however, the result is strikingly simple. The simplest five-dimensional parity-violating term reduces to only two ghost-free terms—the familiar Nieh-Yan term and the standard electromagnetic Chern-Simons term. Remarkably, the model predicts that the helicity-dependent dispersion shift for electromagnetic waves is exactly six times that for gravitational waves, $\Delta\omega^{2}_{ EM}=6\,\Delta\omega^{2}_{GW}$, a background-independent relation. This relation offers a falsifiable test of unification through joint
cosmic microwave background and gravitational wave birefringence observations.
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All authors Haomin Rao, Yunlong Zheng, Qi-Zhe Hou, Jian-Wen Ou, Changyong Zhu
Statistical Mechanics
Pseudo-Distributions: Thermodynamic Geometry and an Empirical Application
Negin Bayrami, Hosein Mohammadzadeh, Hamzeh Agahi et al. (+2 more)
We develop a consistent pseudo-analytic framework based on $g$-calculus for constructing deformed statistical distributions. By mapping standard algebraic operations through a monotone generator function, we systematically derive the associated pseudo-logarithmic and pseudo-exponential structures. Applying this formalism, we introduce a new family of pseudo-distributions that generalizes nonextensive statistical mechanics at both the probability density and cumulative distribution levels, recovering classical and standard nonextensive statistics as limiting cases. We investigate the thermodynamic geometry of the proposed models using the Ruppeiner metric on the
equilibrium manifold. A perturbative analysis around the classical limit reveals that, to leading order, the thermodynamic scalar
curvature is governed solely by the generator deformation parameter, while the nonextensivity parameter remains decoupled. To evaluate the empirical robustness of the framework, we apply the model to analyze the absolute deviations of daily West Texas Intermediate crude oil prices from their hundred-day moving average. Model comparison based on information criteria demonstrates that the proposed pseudo-distributions provide a superior description of these high-frequency financial fluctuations and their heavy-tailed characteristics compared to standard
benchmarks. These results suggest that $g$-calculus offers a flexible and physically grounded mathematical tool for generating deformed statistics and analyzing their
geometric properties.
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All authors Negin Bayrami, Hosein Mohammadzadeh, Hamzeh Agahi, Hossein Mehri-Dehnavi, Zahra Ebadi
General Relativity and Quantum Cosmology
Detector Dependence of Inspiral Christodoulou Gravitational Wave Memory in Binary Black Hole Systems
Jiswin Varghese, Jyothipriya M Shaji and Lyjo K Joseph
The nonlinear gravitational-wave
memory, or Christodoulou
memory effect, is a permanent displacement produced by the self-interaction of gravitational waves predicted by General Relativity. In this work, we present GWMemoryLab, a modular numerical framework for investigating leading-order Christodoulou
memory during the inspiral of non-spinning binary black hole systems within the post-Newtonian approximation. The framework implements modules for binary dynamics, post-Newtonian inspiral
evolution, oscillatory waveform generation, gravitational-wave energy flux, and nonlinear
memory accumulation. Analytical comparisons and convergence tests demonstrate numerical stability. We investigate the dependence of accumulated
memory on binary mass ratio, total mass, and detector low-frequency cutoff. The simulations reveal an optimal total mass that maximizes the observable inspiral
memory for a given detector bandwidth. Within the explored parameter space, the optimal mass follows an approximately inverse dependence on the detector low-frequency cutoff. This behaviour arises from the competition between increasing gravitational-wave luminosity and decreasing inspiral duration as the binary approaches the innermost stable circular orbit. These results provide insight into the detectability of nonlinear gravitational-wave
memory and demonstrate the utility of GWMemoryLab for systematic parameter studies.
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High Energy Astrophysical Phenomena
Impact of disk magnetic fields on the propagation of stellar-scale jets in the magnetically arrested accretion disks of active galactic nuclei
Bao-Quan Huang, Tong Liu and Jian-Fu Zhang
It is widely recognized that active
galactic nucleus (AGN) disks host numerous massive
stars and compact objects.
Stellar-scale jets triggered by collapses of massive
stars and mergers of compact objects could propagate through the disk and produce observable electromagnetic radiation. Magnetically arrested disks (MADs), supported by both numerical simulations and observations, possess strong
magnetic fields (MFs). As jets travel within such environments, the MFs should regulate jet
evolution and shape radiation signatures. In this work, we explore the effects of disk MFs on jet propagation and breakout emission within the MAD framework. We employ a jet-cocoon model that accounts for potential disk-MF effects, including both
magnetic pressure and
magnetic energy dissipation driven by
magnetic reconnection. We find that
magnetic pressure effectively suppresses the lateral expansion of the cocoon, which enhances jet collimation and modestly increases the jet-head velocity. Furthermore,
magnetic pressure effects are more pronounced at relatively low jet powers. In this regime, the breakout luminosity of the jet-head shock is enhanced, while its breakout time is shortened. However, the magnitude of the luminosity enhancement is sensitive to the adopted regime-dependent emission prescriptions. These findings suggest that, within the explored parameter space, disk MFs can facilitate the breakout of low-power jets arising from binary black hole mergers in AGN MADs.
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Mesoscale and Nanoscale Physics
Size-Dependent Band-Tail Localization in Oxide Semiconductors Revealed by Direct Density-of-States Mapping
Chang Niu, Kisoo Nam, Aravindh Shankar et al. (+5 more)
Disorder-induced localization is expected to become increasingly important as amorphous
oxide semiconductor transistors are scaled toward low-dimensional channels, yet the electronic states responsible for this transport regime remain difficult to resolve experimentally. Here, we use a lock-in-based electric-field penetration technique to directly map the effective density of states (DOS) in In-based
oxide semiconductor thin-film transistors (TFTs). The extracted
quantum capacitance, carrier density, and chemical potential reveal a disorder-dominated transport regime in which band-tail states are not merely passive traps, but become screening-active and partially transport-active. Geometry-dependent DOS mapping shows an exponential suppression of the effective DOS with channel length, demonstrating size-dependent band-tail localization and providing a microscopic origin for a distinct localization-induced threshold-voltage roll-off mechanism. Temperature-dependent measurements show that the disorder-dominated DOS is strongly suppressed at low temperatures, while extended diffusive states remain nearly unchanged, confirming the localization origin. By tuning film thickness, O2 annealing, and In/Ga/Zn composition, we further demonstrate systematic suppression of disorder and effective-DOS localization. This work establishes direct DOS mapping as a device-level probe of localization physics and provides a pathway for engineering disorder in low-dimensional
oxide semiconductor electronics.
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All authors Chang Niu, Kisoo Nam, Aravindh Shankar, Jian-Yu Lin, Sanjeev Khare, Sumi Lee, Pramey Upadhyaya, Peide D. Ye
Optics
A Collective Propagation Law of Optical Vortex Constellations and Longitudinal Sensing
Niladri Modak, Rafael F. Barros, Marco Ornigotti et al. (+1 more)
Optical
vortices are ubiquitous phenomena naturally appearing in wave physics, yet higher-order charges inherently split into constellations of lowest-order singularities at the smallest deviation from an ideal situation. While these constellations are common phenomena in real-world scenarios, characterizing their longitudinal
evolution typically relies on exhaustive full-field descriptions or the ambiguous, sequential tracking of individual singularities. Here, we reveal and experimentally demonstrate a simple deterministic law describing the paraxial longitudinal propagation of an arbitrary constellation of optical
vortices in standard Gaussian backgrounds. By mapping the constituting singularity coordinates to their elementary symmetric
polynomials (ESPs), we capture the holistic
evolution of the constellation during propagation, completely bypassing the practical need to sequentially track indistinguishable
vortices. We further show that such complex ESPs provide a useful metrological tool for the estimation of longitudinal displacements. Our results reveal a previously unrecognized compact description of collective
vortex dynamics, introducing a new route to longitudinal sensing through singularimetry.
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All authors Niladri Modak, Rafael F. Barros, Marco Ornigotti, Robert Fickler
Quantum Physics
Quantum uncertainty in a macroscopic domain
Othman Q. Malhas and Bacim Alali
We develop a classical model-theoretic representation of partial Boolean
algebras and use it to formulate
quantum-like uncertainty without abandoning classical propositional logic. Given a surjection from the initial formulæ\ of a propositional
language onto a partial Boolean
algebra $(\mathcal V,\Pi)$, we construct a consistent theory $\mathcal T_g$ whose core—the ordered set of equivalence classes of initial formulæ—is isomorphic to $(\mathcal V,\Pi)$. Its models are characterized as upward-closed clusters, yielding a model-theoretic formulation of KS-colourability: an $n$-dimensional partial Boolean
algebra is KS-colourable exactly when the induced theory has a model meeting every pre-frame in one primitive formula. For finite-spectrum observables, uncertainty is defined by the number of locally admissible atomic outcomes. Dispersion-free models are characterized by the singleton pre-frame condition. With an additional measurement-update postulate, a finite example shows how measurement of an incompatible observable can destroy sharpness, providing a model-theoretic form of back-action. A $12$-vertex partial Boolean
algebra is KS-colourable, whereas a rigorously constructed $140$-vertex, four-dimensional partial Boolean
algebra is not, as shown by a parity argument; its incidence structure is isomorphic to the Peres $24$-ray, $24$-basis configuration in $\mathbb R^4$. Macroscopic interpretations show that these phenomena arise from the organization of propositions and models rather than from nonclassical deduction. Finally, we relate certain models to the probability-one propositions of pure states and density operators, while emphasizing that such certainty models do not determine the full
quantum state.
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Instrumentation and Methods for Astrophysics
Pointing Model Meets Deep Learning: A Retrospective Study on a MeerKAT+ Telescope Applying Deep Learning Methods for Blind Pointing Corrections
Stefan Thoms and Matthias Reichert
This study aims to compare the effectiveness of deep learning methods, specifically Feedforward Neural Networks (FNNs), with traditional Pointing Models (PMs) for compensating Blind Pointing Errors in astronomical instruments. Ambitious projects like the ongoing study for the Atacama Large Aperture Submillimeter
Telescope (AtLAST) inspired the investigation of possible improvements to traditional Pointing Error (PE) modeling. The study assesses the practicality of FNNs by applying them to data from an instrument in operation: a precursor MeerKAT+
telescope from the Max Planck Institute for
Radio Astronomy (MPIfR), intended to extend the current MeerKAT
Radio Telescope Array at the South African
Radio Astronomy Observatory (SARAO) site in the Meerkat National Park in South Africa.
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Materials Science
Machine-learning octet $AB$-type binary compounds across chemical space with domain knowledge of the interatomic bond
Rohan Kumar, Mariano D. Forti, Aakash A. Naik et al. (+2 more)
The prediction of the structural stability of octet $AB$-type binary compounds is a classical materials informatics problem. The challenge is to capture the relative stability of 4-fold coordinated atoms in zincblende ($\beta$-ZnS) structure and 6-fold coordinated atoms in rocksalt (NaCl) structure, modulated by charge transfer and atomic-size differences. Previous structure maps and machine-learning approaches used atomic features such as valence-electron count, ionization potential and atomic radii, using either physical intuition or symbolic regression. Here, we demonstrate that explicitly incorporating the domain knowledge of the interatomic bonds can significantly and systematically improve the prediction of $\beta$-ZnS/NaCl stability. We encode this bonding information through a coarse-grained representation of the local electronic structure obtained by a recursive solution of a tight-binding bond model. The underlying pairwise
Hamiltonians are taken from downfolded eigenstates of density-functional theory calculations for diatomic molecules and thereby include domain knowledge of the bond between specific $A-B$ pairs. The benefit of this description is demonstrated with an ensemble of independently trained Kernel Ridge or symbolic regression models combined with sequential feature selection. The obtained models are compared to a previous symbolic-regression model using the same set of ab initio calculations for octet binaries as training data. We find a significant improvement in the prediction of the formation energy difference of $AB$ compounds as compared to previous works and demonstrate that an increasing amount of bond-informed recursion features improves the predictive accuracy.
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All authors Rohan Kumar, Mariano D. Forti, Aakash A. Naik, Luca M. Ghiringhelli, Thomas Hammerschmidt
Mesoscale and Nanoscale Physics
Gradient-based optimization of non-Abelian fractional quantum states in patterned superlattices
Yifei Guan, Lichen Yu, Zizhuang Liu et al. (+2 more)
The realization of fractional Chern
insulator (FCI) states in moiré
heterostructures has attracted intense interest in the study of correlated topological states. So far, most experimentally realized FCI states may be interpreted as
lattice analogues of Abelian fractional
quantum Hall (FQH) states. Realizing non-Abelian FCI states is an important challenge in the field. Patterned dielectric superlattices provide a versatile platform for engineering topological flat bands. Such systems offer substantial structural flexibility and tunability, because their
lattice patterns, periods, and other structural parameters can all be designed and fabricated. Here, we provide a gradient-based optimization workflow to design non-Abelian fractional states in patterned
bilayer graphene superlattices. The experimentally relevant structural parameters of the superlattice devices are gradient-optimized to favor a flat Chern band with
quantum-
geometric properties reminiscent of those of the first excited Landau level. Exact diagonalization calculations at 1/2 filling of the optimized Chern band naturally yield non-Abelian FCIs. We apply this workflow to triangular, honeycomb, and kagome patterned superlattices and find robust non-Abelian FCIs over a large region of the parameter space spanned by superlattice constant and vertical potential drop. Our work thus establishes an experimentally feasible framework for exploring non-Abelian FCIs in realistic patterned-superlattice devices.
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All authors Yifei Guan, Lichen Yu, Zizhuang Liu, Xin Lu, Jianpeng Liu
High Energy Physics (Phenomenology)
Transverse distributions of the energy-momentum tensor for a spin-$3/2$ baryon
Hui-Jae Lee, Ki-Hoon Hong, June-Young Kim et al. (+1 more)
We develop a multipole description of transverse distributions of the energy-momentum tensor for a
spin-$3/2$
baryon in frames connected by a longitudinal boost. In the transverse Breit frame, the $T^{00}$, $T^{03}$, and $T^{33}$
matrix elements are expressed through seven multipole form factors for energy, angular momentum, and stress. At finite longitudinal momentum, we factorize the Lorentz mixing of these three components from the
spin-$3/2$ Wigner rotations of the external states. The resulting elastic-frame
matrix elements contain six transverse multipoles, whose
Fourier transforms define the distributions of energy, longitudinal momentum, and longitudinal momentum flux. We also calculate $T^{++}$, $T^{+-}$, and $T^{--}$ directly with light-front Rarita-Schwinger spinors. The elastic-frame construction provides a continuous interpolation from the transverse Breit frame to the infinite-momentum frame. In this limit, the Wigner rotation becomes the Melosh rotation, and the leading elastic-frame
matrix elements reproduce the corresponding light-front results. Using the $\Delta$-
baryon gravitational form factors obtained in the Skyrme model as a representative numerical input, we find that the energy distribution is dominated by the energy monopole defined in the transverse Breit frame and changes only weakly under longitudinal boosts. Through boost mixing, this monopole provides the dominant contribution to the longitudinal momentum distribution and its flux at finite $P_z$. For a longitudinally polarized
spin-$3/2$ target, the distributions contain only the monopole contributions, whereas those of a transversely polarized target exhibit
spin-dependent quadrupole and octupole deformations and a dipole that shifts their maxima.
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All authors Hui-Jae Lee, Ki-Hoon Hong, June-Young Kim, Hyun-Chul Kim
Earth and Planetary Astrophysics
Addressing Exoplanetary Degeneracies Through Geometry: Application to Asynchronously Rotating Systems
Mradumay Sadh
This study augments the geometry-based InstellCa code that calculates accurate irradiance values to InstellCa–2, which computes the longitude averaged instellation over a given latitude on the
planet along with its effective temperature profile. The estimation of instellation is performed considering the
planet as a 3D body that asynchronously rotates, causing a varying zenith angle of the
star resulting in a diurnal cycle. This serves as a specialised case study to demonstrate how the combination of this relative rotation and extreme proximity to host-
stars can affect the estimated effective temperatures of close-in
planets. 55 Cancri e is selected specifically to demonstrate the importance of this effect as it has been earlier hypothesised to exhibit asynchronous rotation and also has a debated scientific discourse about the existence of an atmosphere on the
planet. The TRAPPIST-1 system, being a multi-planetary system susceptible to mean motion resonances, also serves as an interesting exemplar case to demonstrate these effects. Incorporating the
stellar zenith angle to the geometrical analysis allows the possibility of physically feasible Bond albedo values that would otherwise be prohibited if a synchronously rotating bare rock scenario is assumed. Consequently, the degeneracies in the modelling of different atmospheric states of such
planets can be reduced if the correct geometry is taken into account.
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Instrumentation and Methods for Astrophysics
Optimizing Wavefront-Deformation Sensor Placement for Active Radio-Telescope Surfaces
Stefan Thoms, Martin Timpe and Matthias Reichert
Next-generation high-frequency
radio telescopes require primary-surface accuracies that passive structures alone cannot reliably achieve. The Atacama Large Aperture Submillimeter
Telescope (AtLAST), a 50 m single-dish concept operating up to $\approx$ 1 THz, imposes a $\approx$ 20 $\mu$m rms surface-accuracy requirement across its full aperture. This is practically unattainable for a purely passive reflector subject to gravitational, thermal, and wind-induced deformation. Closed-loop active collimation and surface control are therefore imperative, which in turn requires the deformation field to be known across the full aperture in real time. Measuring it directly at the necessary resolution across the complete surface is, however, hardly feasible; instead, the current AtLAST concept development foresees reconstructing the surface from a limited set of discrete sensor positions. An algorithmic framework is presented that optimizes the number and placement of these sensors to maximize the reconstructability of the deformation field. Finite-element analysis (FEA) load cases (
gravity, thermal, wind) define the deformation space, from which a data-driven Proper Orthogonal Decomposition (POD) basis is derived; sensor positions are then chosen by a greedy optimization
algorithm and then assessed via leave-one-out cross-validation. Applied to FEA deformations of AtLAST's Back-Up Structure (BUS), and assuming a sensor noise of 5 $\mu$m rms, the method reconstructs all load cases with 50 sensors to below 2.7 $\mu$m rms (worst case) residual (BUS-) surface error.
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Atomic Physics
Stroboscopic Raman Spectroscopy of Atom Optics in Quasi-Bragg Regime
Joel Gomes Baptista, Louis Pagot, Sébastien Merlet et al. (+2 more)
Quasi-Bragg regime is a good compromise for large-momentum-transfer atom interferometry, allowing for scaling up the interferometric area, while constraining the population of unwanted states. Separation of momentum states via standard time of flight methods, however, can be challenging when using
laser-cooled atoms, rather than ultracold atoms with sub-
recoil velocity distribution. To overcome this limit, we use Raman spectroscopy for stroboscopic sampling of the atomic state
evolution in momentum space during the interrogating
laser pulses. We quantitatively characterize atom optics employing two-
photon (2___k) and multi-
photon (6___k) Bragg transitions, the latter being optionally enhanced with optimal control protocol. We closely match the observed dynamics of the atomic state with simulations. Finally, we perform momentum spectroscopy of the output states in a 6___k Bragg gravimeter.
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All authors Joel Gomes Baptista, Louis Pagot, Sébastien Merlet, Leonid Sidorenkov, Franck Pereira Dos Santos
Quantum Gases
Jaynes–Cummings dynamics of fermionic heteronuclear dimers in the Mott regime
R. J. Lewis-Swan and K. V. Kheruntsyan
We formulate and exactly solve a model for coherent association and dissociation of fermionic heteronuclear dimers in the deep-
lattice Mott regime. Starting from the onsite three-component atom–molecule
Hamiltonian, we show how the single-site model maps to the paradigmatic Jaynes–Cummings
Hamiltonian from
quantum optics. In this mapping, the fermionic molecular/free-atom sector forms an effective two-level system, while the bosonic atomic mode plays the role of the oscillator degree of freedom. We fix the conserved number of fermionic constituent atoms to one but allow an arbitrary conserved number $N$ of bosonic constituent atoms. The accessible doublet is then $|e,N-1\rangle\leftrightarrow|g,N\rangle$, and the coherent conversion coupling is bosonically enhanced to $\chi\sqrt{N}$. Exact analytic expressions are derived for molecular dissociation, atom-pair association, mode populations, and
boson–
fermion correlation dynamics. The model provides a transparent matter-wave realization of Jaynes–Cummings physics in a heteronuclear Bose–
Fermi system and an exactly solvable setting for understanding coherent atom–molecule conversion and bosonic enhancement in
lattice systems.
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Materials Science
All-Electron Single-Atom Reference Correction for Absolute Transition Energies in Fixed-Reference PAW-XCH Calculations
Yinan Wang and Teruyasu Mizoguchi
The transition energy of a core-loss spectrum comprises a transferable atomic core-reference contribution and a material-dependent response that determines chemical shifts. Density functional theory calculations commonly underestimate absolute transition energies. In VASP, the same PAW
dataset is used for the ground and core-excited occupations, retaining the ground-state atomic reference when the core occupation changes and thereby omitting the associated all-electron atomic reference change. We evaluate this change using self-consistent single-atom calculations and construct a residual atomic reference correction from the valence reference change and isolated-atom total-energy response. Comparisons with an independent ultrasoft-pseudopotential implementation demonstrate numerical consistency of the all-electron reference for K, L1, and L2,3 core holes, while representative corrected spectra approach the experimental absolute energy scale. For a fixed element, edge, and core-hole scheme, the atomic reference terms cancel from energy differences, showing that same-element chemical shifts are governed by the double difference of the supercell total energy. At the Al and Si L2,3 edges, the near-edge spectral shape additionally depends strongly on the PAW representation of low-lying 3d-like unoccupied states.
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Quantum Physics
A Heterogeneous Distributed Architecture for Quantum Simulation
John Stack, Sitong Liu, Abhinav Anand et al. (+6 more)
Architectural specialization and distribution can help scale fault-tolerant
quantum computers, but may also introduce substantial overheads from communication, routing, and resource duplication. We introduce a heterogeneous distributed architecture in which a magic core is connected to an extensible storage system composed of one-dimensional lanes of specialized cold-storage nodes. The storage system supports parallel random access to Pauli string parities. This organization is particularly well suited to fermionic
quantum simulation, enabling parallel execution of the highly non-local Pauli strings arising from these systems. We evaluate the architecture on fault-tolerant simulations of the dynamics of the
Fermi-Hubbard and sparse Sachdev-Ye-Kitaev (SYK) models on systems of up to 450 logical
qubits. These workloads exhibit complementary communication structures:
Fermi-Hubbard produces a spectrum of interactions from local to non-local shaped by
lattice geometry, whereas sparse SYK produces highly non-local and overlapping Pauli operators. For a Trotter step of a 450-logical-
qubit Fermi-Hubbard workload, a six-lane system with 30 T-state factories is within approximately $1.4\times$ the wall-clock time of a homogeneous distributed architecture with 4 times as many T-state factories and substantially greater connectivity and sites for injecting magic. For matched T-factory counts, our architecture is $\sim 2\times$ faster.
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All authors John Stack, Sitong Liu, Abhinav Anand, Inder Monga, Yuan Liu, Erhan Saglamyurek, Pedro L. S. Lopes, Frank Mueller, Katherine Klymko
Quantum Physics
Squeezing for dispersive readout of NV magnetometer
A.M. Kozodaev, S.M. Drofa, P.G. Vilyuzhanina et al. (+9 more)
Nitrogen vacancy centers in diamond have established themselves as good sensing element for various type of sensors. In particular magnetometers based on diamond
impurities are quickly developing and are already on the
market. Yet, optical readout in these systems complicates system design. Recently schemes of dispersive readout of nitrogen vacancy
spin state using high finesse dielectric cavities for microwave field were proposed, which do not use the optical readout scheme. However, only shot noise based estimates were so far done for sensitivity of these devices. Here we provide detailed analysis of various practically relevant noise and loss sources for such a system. Furthermore, we consider the possibility of using the squeezing
quantum state of the probing microwave field and show it allows to improve the device performance even at room temperature.
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All authors A.M. Kozodaev, S.M. Drofa, P.G. Vilyuzhanina, A. Chernyavskiy, N.I. Salangin, A.N.Smolyaninov, S.Ya. Kilin, I.S. Cojocaru, S.V. Bolshedvorskii, V.V. Soshenko, F.Y. Khalili, A.V. Akimov
Superconductivity
Exchange-induced suppression of superconductivity in a nano-skyrmion lattice - superconductor hybrid
Dongfei Wang, Wenbin Li, Eric Mascot et al. (+1 more)
Engineered magnet-
superconductor hybrids have recently been identified as promising platforms for the investigation of topological superconductivity. Beyond ferro- and
antiferromagnetic structures, coupling non-collinear
spin textures, such as skyrmion
lattices, to
superconductors offers an exciting route for creating and manipulating unconventional superconducting states. In this work, by preparing monolayer Fe on Ir(111) thin films grown epitaxially on a Nb(110) surface, we realize a hybrid system of a nano-skyrmion
lattice proximitized to a superconducting substrate. Scanning tunneling spectroscopy shows that superconductivity becomes suppressed by the Fe nano-skyrmion
lattice, with both the superconducting gap and coherence peaks disappearing. Tight-binding calculations reveal that with increasing exchange coupling, the gap is progressively filled up and eventually superconductivity gets quenched. These results reveal microscopic constraints for designing topologically non-trivial states based on magnet-superconducting
heterostructures.
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All authors Dongfei Wang, Wenbin Li, Eric Mascot, Roland Wiesendanger
Quantum Physics
Evidence for Counterfactual Violation of Local Conservation Laws in Quantum Events
Patrick Cameron, Francesco Di Colandrea, Filippo Cardano et al. (+1 more)
Physical conservation laws, such as those of energy and momentum, are generally believed to hold exactly and locally in spacetime, including in
quantum phenomena. Yet Aharonov, Popescu, and Rohrlich (APR) recently argued, on the basis of a thought experiment, that individual
quantum events, unlike ensemble averages, may occasionally violate local conservation laws. Their argument relies on the wave phenomenon known as "superoscillations", which APR themselves discovered more than 30 years ago. Here we provide experimental evidence for such a violation. We extract
photons from a small superoscillatory region near the core of an optical
vortex and show that their mean transverse momentum is statistically incompatible with a general bound implied by local momentum conservation. The derivation of this bound requires only the theoretically well-supported assumption that the extraction mechanism does not alter the
photons' mean transverse momentum. We also detect
photons with high transverse momentum at a rate significantly exceeding that predicted by a model assuming local momentum conservation. Because this violation can be established only counterfactually and through postselection, it does not conflict with relativistic causality. Our results may represent the first example of a distinct form of
quantum nonlocality that does not explicitly rely on
entanglement.
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All authors Patrick Cameron, Francesco Di Colandrea, Filippo Cardano, Lorenzo Marrucci
High Energy Physics (Experiment)
Silent coverage failures in rare-event searches and a degeneracy index that predicts them
Davide Pagano
Searches for new physics in low-background experiments infer a non-negative signal strength from few events and often report an upper limit. Nominal frequentist coverage requires both a valid interval construction and an adequate data model. We study how controlled model departures affect lower- and upper-endpoint coverage for six interval procedures in an exact Poisson counting experiment, dark-matter
recoil spectra, and a neutrinoless-double-beta-decay peak search. We introduce the Poisson–Fisher degeneracy index $\mathcal I_{\mathrm{PF}}(\delta\nu;\vartheta_0)=(\beta,\gamma)$, which maps a specified expected-count deformation, after projection onto the complete fitted tangent space, to $\beta$, the signed fitted signal shift in profiled standard-error units, and $\gamma$, the Poisson–Fisher norm of the unabsorbed residual. Locally, the sign of $\beta$ identifies the threatened endpoint, while larger $\gamma$ implies greater detectability by the saturated-Poisson goodness-of-fit test used here at a fixed $5\%$ type-I error rate. Across the studied deformations, positive signal-like bias degrades discovery-side coverage while making upper limits conservative; negative signal bias from overestimated signal efficiency can make the upper endpoint undercover. Calibration under the nominal simulator does not protect against misspecification of that simulator relative to the data-generating process. A plausible deformation with large $|\beta|$ and small $\gamma$ may therefore evade diagnosis and should be represented by a nuisance constrained with auxiliary information or included in a defensible envelope. In the exactly collinear constrained-nuisance
benchmark, modelling the deformation restores coverage at the evaluated grid points, at a quantifiable cost in interval sensitivity.
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Nuclear Theory
P. Laskos-Patkos, P.S. Koliogiannis and Ch.C. Moustakidis
The new era of multi-messenger astronomy requires the accurate and self-consistent derivation of the
nuclear equation of state at high temperature. In the present work, we focused on the calculation of hot hybrid equations of state, studying the different
evolution stages of a proto-
neutron star with a
quark matter core (proto-hybrid
star). For the hadronic matter we used two distinct Skyrme effective interactions, while for
quark matter the well-known vector MIT bag model was employed. To model the era of trapped
neutrinos in the system we considered the global conservation of
lepton fraction which resulted in an equation of state with an extended mixed phase. For periods following the
neutrino diffusion phase of a proto-
neutron star, the equations of state were modelled using both the Maxwell and the Gibbs construction depending on the assumption for either local or global electric-charge conservation. With the use of the derived hybrid models, we solved the Tolman-Oppenheimer-Volkov equations to describe the corresponding hybrid
star configurations. Finally, we investigated how the structure of proto-hybrid
stars evolves, using constant rest mass sequences. We found that regardless of whether electric-charge is globally or locally conserved, the earlier stages of a hybrid
star's life may play a crucial role on the determination of its maximum possible gravitational mass in later stages.
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Astrophysics of Galaxies
Statistical inference of fast radio burst environments using galaxy number density
Vignesh V.V. Rao, Tetsuya Hashimoto, Tomotsugu Goto et al. (+9 more)
Fast
radio bursts (FRBs) are bright, millisecond-duration
radio transients of unknown origin. They are categorized as repeaters and non-repeaters, possibly indicating distinct progenitor types. However, validating this distinction is difficult because of the limited number of localized FRBs. Large-scale
galactic environments can provide insight into the nature of the host
galaxies of FRBs and their progenitors. High-number-density regions are typically associated with old
galaxies, whereas low-number-density regions are linked to young
star-forming or less massive quiescent
galaxies. In this study, we use
galaxy number density to statistically assess the environments of 19 repeaters and 253 non-repeaters from CHIME Catalog 1, using
galaxies from the WISE x PS1 catalog. A Kolmogorov-Smirnov (KS) test showed no significant difference between the two populations ($p_{\rm KS} = 0.673$). This result indicates that the statistical significance of the difference could depend on small-number statistics, highlighting the necessity of future FRB samples. Intriguingly, a comparison of FRBs with random
galaxy fields suggests that FRBs may preferentially occur in underdense
galactic environments, with a median $p$-value ($p_{\rm KS}$) of $2.84 \times 10^{-2}$ compared to random
galaxy apertures.
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All authors Vignesh V.V. Rao, Tetsuya Hashimoto, Tomotsugu Goto, Shotaro Yamasaki, Mohanraj Madheshwaran, Sridhar Gajendran, Tomoki Wada, Simon C.-C. Ho, Terry Long Phan, Yuri Uno, Amos Y.-A.Chen, Hiroto Masaka
Optics
High-speed volumetric amplitude-spectrum dynamic optical coherence tomography by neural network with multi-burst scanning
Yusong Liu, Ibrahim Abd El-Sadek, Atsuko Furukawa et al. (+3 more)
Dynamic optical coherence
tomography (DOCT) enables label-free, three-dimensional (3D) assessment of tissue dynamics. However, it suffers from long acquisition times because conventional time-spectrum DOCT requires hundreds of repeated OCT frames per location. Here we present a neural network (NN) framework integrated with a non-uniform-time scanning protocol (multi-burst scan) to accelerate amplitude-spectrum DOCT (AS-DOCT). Combining 3D convolutional and long-short term
memory (LSTM) layers with dual inputs (the temporal OCT sequence and its pseudo-amplitude spectrum), the model generates AS-DOCT images from only 16 frames per location. Validated on 29 cancer spheroids, the proposed method resolved distinct functional domain structures with high fidelity (structural similarity index metric (SSIM) > 0.8) and enabled full volumetric AS-DOCT acquisition in 26.2 seconds. This method will enable high-throughput 3D dynamic tissue screening.
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All authors Yusong Liu, Ibrahim Abd El-Sadek, Atsuko Furukawa, Rion Morishita, Satoshi Matsusaka, Yoshiaki Yasuno
Nuclear Experiment
Tensor analyzing power $T_{20}$ in the reaction $\gamma \vec{d}\to pn$ at photon energies 350-680 MeV
V. V. Gauzshtein, A. I. Fix, V. I. Ivanov et al. (+30 more)
We present measurements of the tensor analyzing power $T_{20}$ in the reaction $\gamma {d}\to pn$ at
photon energies $E_\gamma = 350$-$680$~MeV. The experiment was performed at the VEPP-3 storage ring using an internal tensor-polarized deuterium gas target and a tagged quasi-real
photon beam. The data were obtained for
proton emission angles $\Theta_p = 70^\circ$-$102^\circ$. Comparison with modern
meson-
baryon calculations shows generally satisfactory agreement within the present uncertainties. A theoretical analysis of an extended data set, covering the energy range from threshold to 680~MeV and including both the new data and the previous results from 2007, is presented.
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All authors V. V. Gauzshtein, A. I. Fix, V. I. Ivanov, D. M. Nikolenko, I. A. Rachek, Yu. V. Shestakov, D. K. Toporkov, A. V. Yurchenko, S. A. Zevakov, G. N. Baranov, A. V. Bogomyagkov, V. M. Borin, E. M. Darwish, D. V. Dorokhova, V. L. Dorokhov, S. E. Karnaev, A. A. Kovalenko, V. N. Kudryavtsev, M. I. Levchuk, E. B. Levichev, I. B. Logashenko, A. Yu. Loginov, T. V. Maltsev, R. Z. Mamutov, I. N. Okunev, P. A. Piminov, L. I. Shekhtman, E. A. Simonov, S. V. Sinyatkin, M. A. Skamarokha, E. V. Starostina, I. A. Ulev, A. N. Zhuravlev
Mathematical Physics
Theoretical analysis of the maximum range of a projectile released from a pendulum
Ken Yamamoto
The motion of a projectile released from a simple pendulum is analyzed, with particular emphasis on investigating the optimal release angle that maximizes the horizontal range and the corresponding maximum range. This system serves as a simplified model of the Tarzan jump problem. Using simple analytical methods, the optimal release angle is shown to be characterized by a cubic equation and to increase with the initial velocity. In addition, asymptotic expressions for both the optimal angle and maximum range are derived in the limits of low and high initial velocity.
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Quantum Physics
Quantum Hashing Circuit Optimization for Arbitrary Qubit Connectivity Graphs Based on 1-Covering Path
Kamil Khadiev, Aliya Khadieva, Vadim Sagitov et al. (+2 more)
One of the obstacles to the widespread adoption of
quantum computing is the problem of efficient
circuit synthesis. Current
quantum hardware has limited connections between
qubits, with each
qubit connected to only a few others. This means that the
circuit has to be transformed to accommodate this. In this paper, we present an
algorithm that converts a
circuit containing a sequence of CNOT gates into a form that is suitable for arbitrary
quantum computer architectures. Although we demonstrate the
algorithm only in the context of
quantum fingerprinting, similar gate sequences are prevalent in
quantum algorithms; for instance, they are present in the textbook
quantum Fourier transform. We present a
quantum circuit implementation of the
quantum hashing
algorithm (
quantum fingerprinting
algorithm) for a
quantum device with restrictions on the application of two-
qubit gates that are expressed as a
qubit connectivity graph. As an example of usage of the technique, we apply it to
quantum finite automata recognizing the unary $MOD_p=\{a^\ell: \ell \bmod p=0\}$
language, and the $EQ_p=\{a^\ell b^r: \ell \equiv r \pmod p\}$
language. Given the enhancements that our
algorithm provides~– for instance, in one case it achieves a 16%–17% decrease in CNOT
circuit cost~– we believe it could also be useful in a broader
quantum compilation context.
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All authors Kamil Khadiev, Aliya Khadieva, Vadim Sagitov, Kamil Khasanov, Mansur Ziatdinov
Instrumentation and Methods for Astrophysics
Foreground Subtraction with a Tensor-Based Oriented Singular Value Decomposition Method for HI Experiments
Shifan Zuo, Xuelei Chen and Yi Mao
We introduce a native tensor-based framework for foreground mitigation in 21\,cm intensity mapping (IM), utilizing the Oriented Singular Value Decomposition (O-SVD)
algorithm. While 21\,cm IM is a powerful probe of the large-scale structure of the Universe, its efficacy is severely limited by astrophysical foregrounds that are orders of magnitude brighter than the cosmological signal. Traditional mitigation strategies often necessitate flattening multidimensional data cubes into two-dimensional
matrices, a process that potentially compromises the intrinsic spatial-spectral correlations by treating distinct spatial pixels as independent samples. By treating multi-frequency sky maps and angular power spectra as third-order tensors, the O-SVD method performs decomposition directly on the multilinear
manifold, preserving the underlying physical
topology and leveraging the distinct coherence properties of astrophysical foregrounds across different dimensions. We demonstrate the performance and versatility of the O-SVD framework through its application to high-fidelity simulations from the SKA Science Data Challenge 3a (SDC3a) and real-world observational data from the Tianlai Cylinder Pathfinder Array. Our results indicate that O-SVD provides a robust and universal approach for foreground subtraction, achieving high-fidelity signal recovery while offering superior performance compared to conventional
matrix-based Singular Value Decomposition (SVD) methods.
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Atmospheric and Oceanic Physics
3D Modeling of a Tethered Autogyro with Articulated Rotors and Attitude Control using Differential Rotor Braking
Tasnia Noboni and Tuhin Das
A tethered autogyro with articulated rotors can operate as an unmanned aerial vehicle capable of energy-efficient, long-duration deployment by utilizing ambient wind energy to sustain flight. This article presents a model-based attitude control technique for such a system using a full-fidelity dynamic model. Using Lagrangian approach combined with Blade Element Momentum Theory and catenary mechanics, a previously developed 2D hybrid model is extended to three dimensions. The new model describes the complete rigid-body motion of the frame, including roll and yaw dynamics, and is augmented with rotor speed and flapping degrees of freedom for each blade.
Equilibrium characteristics are examined through steady-state responses and compared with the prior model. The resulting trends of
equilibria are found to be consistent with those reported in the literature. A feedback control strategy based on regenerative differential rotor braking is developed to modulate all three attitude angles. Simulations demonstrate effective attitude regulation and stable flight.
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