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33c14abbd7460789a55a237c0ab1d97163cbd578ad2eda27f623adb80f802f4f
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2026-01-01T00:00:00-05:00
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BF-APNN: A Low-Memory Method for Accelerating the Solution of Radiative Transfer Equations
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arXiv:2512.24534v1 Announce Type: new Abstract: The Radiative Transfer Equations (RTEs) exhibit high dimensionality and multiscale characteristics, rendering conventional numerical methods computationally intensive. Existing deep learning methods perform well in low-dimensional or linear RTEs, but still face many challenges with high-dimensional or nonlinear RTEs. To overcome these challenges, we propose the Basis Function Asymptotically Preserving Neural Network (BF-APNN), a framework that inherits the advantages of Radiative Transfer Asymptotically Preserving Neural Network (RT-APNN) and accelerates the solution process. By employing basis function expansion on the microscopic component, derived from micro-macro decomposition, BF-APNN effectively mitigates the computational burden associated with evaluating high-dimensional integrals during training. Numerical experiments, which involve challenging RTE scenarios featuring, nonlinearity, discontinuities, and multiscale behavior, demonstrate that BF-APNN substantially reduces training time compared to RT-APNN while preserving high solution accuracy. Moreover, BF-APNN exhibits superior performance in addressing complex, high-dimensional RTE problems, underscoring its potential as a robust tool for radiative transfer computations.
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https://arxiv.org/abs/2512.24534
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Academic Papers
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6f10b252f4059374f0be6cebde89e31e118d2e6873f32ca29397245a62baebee
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2026-01-01T00:00:00-05:00
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Imaging nanoscale photocarrier traps in solar water-splitting catalysts
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arXiv:2512.24543v1 Announce Type: new Abstract: Defects trap photocarriers and hinder solar water splitting. The nanoscale photocarrier transport, trapping, and recombination mechanisms are usually inferred from ensemble-averaged measurements and remain elusive. Because an individual high-performing nanoparticle photocatalyst may outperform the ensemble average, design rules that would otherwise enhance catalytic efficiency remain unclear. Here, we introduce photomodulated electron energy-loss spectroscopy (EELS) in an optically coupled scanning transmission electron microscope (STEM) to map photocarrier localization. Using rhodium-doped strontium titanate (SrTiO3:Rh) solar water-splitting nanoparticles, we directly image the carrier densities concentrated at oxygen-vacancy surface trap states. This is achieved by separating photothermal heating from photocarrier populations through experimental and computational analyses of low-loss spectra. Photomodulated STEM-EELS enables angstrom-scale imaging of defect-induced photocarrier traps and their impact on photocatalytic efficiency.
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https://arxiv.org/abs/2512.24543
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Academic Papers
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d42781663820a6806285ff6472cdb2b17d90bf5b377522144fa82f6f6193a854
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2026-01-01T00:00:00-05:00
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Computing Flux-Surface Shapes in Tokamaks and Stellarators
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arXiv:2512.24544v1 Announce Type: new Abstract: There is currently no agreed-upon methodology for characterizing a stellarator magnetic field geometry, and yet modern stellarator designs routinely attain high levels of magnetic-field quasi-symmetry through careful flux-surface shaping. Here, we introduce a general method for computing the shape of an ideal-MHD equilibrium that can be used in both axisymmetric and non-axisymmetric configurations. This framework uses a Fourier mode analysis to define the shaping modes (e.g. elongation, triangularity, squareness, etc.) of cross-sections that can be non-planar. Relative to an axisymmetric equilibrium, the additional degree of freedom in a non-axisymmetric equilibrium manifests as a rotation of each shaping mode about the magnetic axis. Using this method, a shaping analysis is performed on non-axisymmetric configurations with precise quasi-symmetry and select cases from the QUASR database spanning a range of quasi-symmetry quality. Empirically, we find that quasi-symmetry results from a spatial resonance between shape complexity and shape rotation about the magnetic axis. The quantitative features of this resonance correlate closely with a configuration's rotational transform and number of field periods. Based on these observations, it is conjectured that this shaping paradigm can facilitate systematic investigations into the relationship between general flux-surface geometries and other figures of merit.
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https://arxiv.org/abs/2512.24544
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Academic Papers
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4d855ef2255141069f42337bea82d2ac055fef05e17369a2cb4019f674670626
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2026-01-01T00:00:00-05:00
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ExoAtom: A Database of Atomic Spectra in ExoMol Format
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arXiv:2512.24612v1 Announce Type: new Abstract: We present the ExoAtom database, www.exomol.com/exoatom, an extension of the ExoMol database to provide atomic line lists in the ExoMol format. ExoAtom is designed for detailed astrophysical, planetary, and laboratory applications. ExoAtom currently includes atomic data for 80 neutral atoms and 74 singly charged ions. These data are extracted from both the NIST and Kurucz databases, with 79/71 atoms/ions sourced from NIST and 38/37 atoms/ions sourced from Kurucz. ExoAtom uses the file types .all, .def, .states, .trans and .pf as fundamental components for structuring atomic data in a consistent hierarchy. The .states file contains quantum numbers, uncertainties, lifetimes, etc. The .trans file specifies Einstein A coefficients and their associated wavenumbers. The .pf file provides partition functions over a wide grid of temperatures. Post-processing of the ExoAtom data is provided by the program PyExoCross. Future development of ExoAtom will include additional ionization stages.
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https://arxiv.org/abs/2512.24612
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Academic Papers
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f269da764333ec0bf5f3bb9a0731a6523c16b55858a7799e8fa7fe9916337910
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2026-01-01T00:00:00-05:00
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Pathway to Optical-Cycle Dynamic Photonics: Extreme Electron Temperatures in Transparent Conducting Oxides
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arXiv:2512.24641v1 Announce Type: new Abstract: We find that transparent conducting oxides (TCOs) exhibit oscillatory (sign-reversing) dynamics on a few optical cycle timescale under extreme electron temperatures. We demonstrate a mechanism for such transient dynamics and present an inverse-designed multilayer cavity incorporating an ultrathin TCO layer that supports the oscillatory behavior. This approach yields transmittance oscillations with a period of ~20 fs, which corresponds to three optical cycles of the probe beam. To achieve a similar oscillatory modulation in the refractive index, we incorporate a TCO electron-acceptor layer on top of the inverse-designed cavity, enabling thermionic carrier injection at the TCO heterojunction. The resulting acceptor layer achieves a striking {\Delta}n response time as short as 9 fs, approaching a single optical cycle, and is further tunable to sub-cycle timescales. The findings not only clarify the elusive transient physics in TCOs but also demonstrate, for the first time, the critical role of electron temperatures in driving oscillatory dynamic responses. More broadly, we establish TCO-based thermionic carrier injection as a practical route to novel time-varying photonic media operating on the timescale of an optical cycle, enabling time-reflection, time-refraction, and related dynamic phenomena from the visible to the infrared.
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https://arxiv.org/abs/2512.24641
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Academic Papers
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60ced124a0295881f1388ebd660a83736ff571db206bdecd620a9aa55db8b75a
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2026-01-01T00:00:00-05:00
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Thermodynamics Reconstructed from Information Theory:An Axiomatic Framework via Information-Volume Constraints and Path-Space KL Divergence
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arXiv:2512.24655v1 Announce Type: new Abstract: We develop an axiomatic reconstruction of thermodynamics based entirely on two primitive components: a description of what aspects of a system are observed and a reference measure that encodes the underlying descriptive convention. These ingredients define an "information volume" for each observational cell. By incorporating the logarithm of this volume as an additional constraint in a minimum-relative-entropy inference scheme, temperature, chemical potential, and pressure arise as conjugate variables of a single information-theoretic functional. This leads to a Legendre-type structure and a first-law-like relation in which pressure corresponds to information volume rather than geometric volume. For nonequilibrium dynamics, entropy production is characterized through the relative-entropy asymmetry between forward and time-reversed stochastic evolutions. A decomposition using observational entropy then separates total dissipation into system and environment contributions. Heat is defined as the part of dissipation not accounted for by the system-entropy change, yielding a representation that does not rely on local detailed balance or a specific bath model. We further show that the difference between joint and partially observed dissipation equals the average of conditional relative entropies, providing a unified interpretation of hidden dissipation and information-flow terms as projection-induced gaps.
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https://arxiv.org/abs/2512.24655
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Academic Papers
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6017a16f18b60f4ed0a460137eb259a4b14daff60a817269f4ccd571123a1804
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2026-01-01T00:00:00-05:00
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Panchromatic Absorbing Materials: Molecular Design and Challenges in Photovoltaic Applications
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arXiv:2512.24678v1 Announce Type: new Abstract: Panchromatic absorbing materials are widely regarded as a key strategy for enhancing solar energy utilization and photocurrent generation. However, in artificial molecular systems, broadening the absorption spectrum is often accompanied by fundamental challenges, including bandgap narrowing, poor energy-level alignment, and limited charge-transfer kinetics, indicating that pursuing broadband absorption alone is insufficient to guarantee high photovoltaic performance. This article examines the relationship between design strategies and performance of panchromatic absorbing materials from the perspectives of molecular engineering and photovoltaic devices, with particular emphasis on the delicate balance among molecular electronic structure, charge-transfer characteristics, interfacial energy-level alignment, as well as electron injection, regeneration efficiency, and energy losses. Ultimately, the molecular design of panchromatic photovoltaic materials should move beyond molecular-level optimization toward synergistic tuning among molecules, semiconductors, and electrolytes or active-layer materials, thereby providing concrete conceptual guidance for achieving efficiency optimization rather than simple spectral maximization.
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https://arxiv.org/abs/2512.24678
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Academic Papers
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a25dbda09c0cc7fb4d63a322437c044a8d60d7d825b00243e4caf937c60c6aec
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2026-01-01T00:00:00-05:00
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Scalable ultrafast random bit generation using wideband chaos-based entropy sources
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arXiv:2512.24716v1 Announce Type: new Abstract: The exponential growth of data transmission and processing speeds in modern digital infrastructure requires entropy sources capable of producing large volumes of true randomness for information security. Chaotic emissions from semiconductor lasers are attractive in this context because of their fast dynamics and nonrepetitive behavior. Their spectral bandwidth, however, is typically limited to several tens of gigahertz, which constrains the achievable entropy rate and makes ultrafast random bit generation difficult without substantial post-processing. Here, we demonstrate a chaos-based entropy source that employs optical heterodyning between the chaotic emission from a semiconductor laser and an optical frequency comb, yielding a bandwidth exceeding 100 GHz and an experimentally verified single-channel entropy rate of 1.86 Tb/s. By directly extracting multiple bits from the digitized output of the entropy source, we achieve a single-channel random bit generation rate of 1.536 Tb/s, while four-channel parallelization reaches 6.144 Tb/s with no observable interchannel correlation. This linear scalability suggests that aggregate throughput could reach hundreds of terabits per second with additional parallel channels. The broadband, low-overhead photonic architecture presented here provides a viable route to real-time, ultrafast random bit generation with broad implications for secure communications, high-performance AI computing, and large-scale data analytics.
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https://arxiv.org/abs/2512.24716
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Academic Papers
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3df101a90f3e9e2e11fb9849aff9813be16d51a4c80eff5415f6f4e4c4d851b4
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2026-01-01T00:00:00-05:00
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Achieving High Efficiency And Enhanced Beam Quality In Laser Wakefield Acceleration
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arXiv:2512.24719v1 Announce Type: new Abstract: Laser wakefield acceleration, characterized by the extremely high electric field gradient exceeding 100GV/m, is regarded as a compact and cost affordable technology for the next generation of particle colliders and light sources. However, it has always been a major challenge to effectively increase the energy transfer efficiency from the laser to the accelerated beam, while ensuring the beam quality remains suitable for practical applications. This study demonstrates that the laser with shorter pulse duration allows for a two-step dechirping process of the accelerated electron beam with charge of nanocoulomb level. The electron beams with an energy spread of 1% can be generated with the energy transfer efficiency of 10% to 30% in a large parameter space. For example, one electron beam with the energy of 420MeV, the charge of 5.5nC and the RMS energy spread of 2% can be produced using an 8.3J laser pulse with 7.2fs duration.
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https://arxiv.org/abs/2512.24719
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Academic Papers
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1d582b4cddc7db33589a49db6b82332a7e7477fdebefcb5610e95f1c6667f54e
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2026-01-01T00:00:00-05:00
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Cataloging the nonlinear waves excited by moving a charged body in the dusty plasma medium
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arXiv:2512.24723v1 Announce Type: new Abstract: The nonlinear waves excited by the movement of a charged body in the dusty plasma medium are studied. A charged body moving through a dusty plasma medium can generate diverse nonlinear waves, such as precursors and pinned solitons. These wave excitations under weakly nonlinear and dispersive limits are described theoretically by the forced Korteweg-de Vries (fKdV) type equation. We have examined the role of the driver in shaping and evolving these wave excitations. In particular we studied the effect of primarily three source parameters, namely, amplitude, width, and flow speed, on the evolution of nonlinear structures. The driver generates a perturbation in the stable system configuration, which couples with medium characteristics and eventually evolves into propagating excitations. Our finding shows that the excitation of nonlinear structure by a moving body in a plasma medium is not just dictated by the mach number but also the features of the source such as amplitude and width. As a novel finding apart from pinned and precursor solitons, we observe another nonlinear structure that lags behind the source term, maintaining its shape and speed as it propagates. These features are the first ever theoretical depiction of such lagging structures.
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https://arxiv.org/abs/2512.24723
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Academic Papers
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6ba551a247b44c21378ba62985da14e94510fe0aefc0b9fa90d82e3bbc43957b
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2026-01-01T00:00:00-05:00
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Generalization Capability of Deep Learning for Predicting Drag Reduction in Pulsating Turbulent Pipe Flow with Arbitrary Acceleration and Deceleration
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arXiv:2512.24757v1 Announce Type: new Abstract: The spatiotemporal evolution of pulsating turbulent pipe flow was predicted by deep learning. A convolutional neural network (CNN) and long short-term memory (LSTM) were employed for long-term prediction by recursively predicting the local temporal evolution. To enhance prediction, physical components such as wall shear stress were informed into the training process. The datasets were obtained from direct numerical simulation (DNS). The model was trained exclusively on a limited set of sinusoidal pulsating flows driven by pressure gradients defined by their period and amplitude. Subsequently, 36 pulsating flows with arbitrary non-sinusoidal acceleration and deceleration were predicted to evaluate the generalization capability, defined as the predictive performance on unseen data during training. The model successfully predicted drag reduction rates ranging from $-1\%$ to $86\%$, with a mean absolute error of 9.2. This predictive performance for unseen pulsations indicates that local temporal prediction plays a central role, rather than learning the global profile of the pulsating waveforms. This implication was quantitatively verified by analyzing the differences in periodic $C_f$--$Re_b$ trajectories between the training and test datasets, demonstrating that flows exhibiting local similarity to the training data are more predictable. Furthermore, it was demonstrated that flows exhibiting intermittent laminar--turbulent transition and relaminarization become predictable when such regimes are incorporated into the training data. The results indicate that accurate prediction is achievable provided that the training data sufficiently cover the local flow-state space, highlighting the importance of appropriate training data selection for generalized flow prediction.
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https://arxiv.org/abs/2512.24757
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Academic Papers
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f3f56717e39421903dd6d98ec9cba9d864c7b90c2a7b33f17fe587eb05b9b7bc
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2026-01-01T00:00:00-05:00
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Runaway electron avalanche and macroscopic beam formation: simulations of the DTT full power scenario
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arXiv:2512.24760v1 Announce Type: new Abstract: The transition of the Divertor Tokamak Test (DTT) facility from its initial commissioning phase (Day-0, plasma current $I_{p}=2$ MA) to the full power scenario ($I_{p}=5.5$ MA) introduces a critical shift in the dynamics of runaway electrons (REs) generation. While previous predictive studies of the low-current scenario indicated a robust safety margin against RE beam formation, this work reveals that the exponential scaling of the RE avalanche gain with plasma current severely narrows the safe operational window in the full power scenario. Using the non-linear magnetohydrodynamic code JOREK, we perform comprehensive 2D simulations of the current quench (CQ) phase of several disruption scenarios, systematically scanning initial RE seed currents and injected impurity levels. The results demonstrate that in the full power scenario, the avalanche multiplication factor is sufficiently high ($G_\text{av} \approx 1.3 \cdot 10^5$) to convert a mere 5.5 A seed current into macroscopic RE beams of $\approx 0.7$ MA when large amounts of impurities are present. For even higher RE seeds, the RE current can peak at $ \approx 3.2$ MA, constituting up to $\approx$ 80% of the total plasma current during the CQ. These findings suggest that, unlike the Day-0 phase, the disruption mitigation strategy for the full power scenario involves a careful balance between thermal load mitigation and RE avoidance, necessitating a well-chosen quantity of injected impurities. This work provides the baseline needed for future estimations of RE loads on the plasma-facing components of DTT, which will be essential for designing and positioning mitigation components like sacrificial limiters.
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https://arxiv.org/abs/2512.24760
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Academic Papers
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6d6f73959ed4a6d2c7ecc08b371fdfd871fdbe7b52bb1105abf6fbdfb5a21df7
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2026-01-01T00:00:00-05:00
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Predicting the Oscillatory Regimes of Global Synchrony Induced by Secondary Clusters
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arXiv:2512.24765v1 Announce Type: new Abstract: Synchronization systems with effective inertia, such as power grid networks and coupled electromechanical oscillators, are commonly modeled by the second-order Kuramoto model. In the forward process, numerical simulations exhibit a staircase-like growth of global synchrony, reflecting temporal oscillations induced by secondary synchronized clusters of whirling oscillators. While this behavior has been observed previously, its governing conditions have not been quantitatively determined in terms of analytical criteria. Here, we develop a self-consistent theoretical framework that explicitly characterizes the secondary synchronized clusters. This analysis identifies an onset crossover mass $\tilde{m}^* \simeq 3.865$ for the emergence of secondary clusters and yields quantitative criteria for predicting both the crossover mass and the termination coupling strength at which they vanish. As a result, we determine the oscillatory regimes of coupling strengths over which global synchrony shows temporal oscillations, providing practical guidance for controlling and avoiding undesirable oscillatory behavior in inertial synchronization systems, such as power grids.
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https://arxiv.org/abs/2512.24765
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Academic Papers
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5b12dbafcc41bbf28cc4305750c2d4eea6fba952c265f9ae77e2fdf7787d1c4a
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2026-01-01T00:00:00-05:00
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On Prats' problem with anomalous diffusion
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arXiv:2512.24769v1 Announce Type: new Abstract: The classical Prats' problem of flow instability in a horizontal porous channel saturated by a fluid subject to a buoyancy force is reconsidered. In the original formulation, the driving buoyancy force results from thermal diffusion. This study, however, substitutes thermal diffusion with mass diffusion. Furthermore, the usual scheme of mass diffusion is extended to comprehend also the anomalous phenomena of superdiffusion or subdiffusion. Such phenomena are modelled via a time-dependent mass diffusivity which yields a significant change in the formulation of the stability eigenvalue problem. In particular, the ordinary differential equations governing the time evolution of the perturbations acting on the base throughflow become non-autonomous. This makes a significant difference in the discussion of the conditions leading to instability, with a marked effect of the anomaly in the mass diffusion process. The transition from convective to absolute instability for subdiffusion processes is also addressed.
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https://arxiv.org/abs/2512.24769
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Academic Papers
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393e8e886838635f38c96d43905df3e75aa67c4fc3f5936a83302de42d8e2fc4
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2026-01-01T00:00:00-05:00
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A Dual-Tuned Concentric Multimodal RF Coil for 7T 1H/31P MRSI: Concurrently Enhancing B1 Efficiency Over Single-Tuned References
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arXiv:2512.24786v1 Announce Type: new Abstract: This study presents the design, simulation, and experimental validation of a dual-tuned concentric multimodal surface coil for 7T 1H/31P magnetic resonance spectroscopic imaging (MRSI), developed to significantly enhance 31P B1 efficiency while improving 1H performance. The coil architecture utilizes two interleaved sets of three concentric loop resonators. Intra-nucleus electromagnetic coupling within each three-loop set generates a spectrum of eigenmodes; the operational modes for 1H and 31P were specifically selected because their co-directed current distributions reinforce the magnetic field at the center, yielding B1 patterns that resemble those of conventional single-loop surface coils but with superior efficiency. Full-wave electromagnetic simulations and bench measurements on a fabricated prototype were conducted to characterize the multimodal resonance behavior, scattering parameters, B1 distribution, and 10-g local SAR, using size-matched conventional single-tuned loops as references. The results confirmed that the design reproducibly generated the predicted eigenmode ordering with sufficient spectral separation to prevent interference from parasitic or undesired modes. Notably, the multimodal design achieved an 83% boost in 31P B1 efficiency and a 21% boost in 1H B1 efficiency at the coil center compared to same-sized single-tuned references. Sufficient inter-nuclear decoupling was achieved to prevent signal leakage between channels, and simulations with a human head model confirmed that the peak 10-g local SAR remained comparable to conventional designs. These findings demonstrate that this multimodal concentric design offers a robust and highly efficient solution for multinuclear MRSI at ultrahigh fields, effectively mitigating the sensitivity limitations of X-nuclei without compromising proton-based imaging capabilities.
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https://arxiv.org/abs/2512.24786
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Academic Papers
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b5d6a7990b2c222aa187f187623d45bf1d9e8824651e3d4a8165d72f29022eab
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2026-01-01T00:00:00-05:00
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Circuit-free cardiovascular monitoring via skin-interfaced nanophotonics
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arXiv:2512.24820v1 Announce Type: new Abstract: Continuous cardiovascular monitoring is essential for managing circulatory health and disease, yet most wearable sensors are constrained by reliance on electrical transduction and built-in electronics. We present a circuit-free, wholly optical approach using diffraction from a skin-interfaced nanostructured surface to detect minute skin strains from the arterial pulse. A smartphone camera records the shifting diffraction pattern in real time, removing the need for spectrometers or other optical hardware. In phantom and human studies, we recovered high-fidelity arterial pulse waves and detected benign arrhythmic events in close agreement with a clinical reference. Derived waveforms captured features linked to arterial stiffness, a key cardiovascular risk marker. Our approach uses battery-free, cost-effective, and disposable platforms enabling scalable monitoring for healthcare and broad consumer applications.
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https://arxiv.org/abs/2512.24820
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Academic Papers
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f62a9ed38a3af581fc08a2bd3a9567372a87c1d518e0c2ea9143320d8c0c598f
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2026-01-01T00:00:00-05:00
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In-vivo femtonewton-sensing nanotribology of Tradescantia zebrina leaf cell inner surface using roll rotation detection
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arXiv:2512.24823v1 Announce Type: new Abstract: Accessing the properties of a plant cell interior non-invasively is difficult due to the presence of a cell wall. Nanoparticles larger than 5 nm cannot be readily phagocytosed inside the cell like animal cells. It is here that we realise that Tradescantia zebrina plant cells have prismatic forms of calcium oxalate crystals present inside them naturally. These crystals make a ready choice to study properties of the inner cell surface with the application of optical tweezers. Moreover, out-of-plane rotations in optical tweezers have begun to be explored only recently. The pitch rotation has been detected with high resolution and several applications are explored. In this work, we first study the stable configuration while trapped in linearly polarized optical tweezers and then explore the other out-of-plane configurations to detect the roll rotation at high resolution. Then a micro-rheological analysis is performed to obtain the frictional properties of the inner surface of the plasma membrane of the leaf cell. The size of the particle is about 5 $\mu$m along the diagonal, so that the contact length with the surface is about 200 nm. We measure a frictional force of 18.5 pN at a sensitivity of about 200 fN without averaging.
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https://arxiv.org/abs/2512.24823
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Academic Papers
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c100f5abf48eb33d4d30ba32e81afa120c8186104b411e4f5975393083364ebc
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2026-01-01T00:00:00-05:00
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A Low Background Beta Detection System using a Time Projection Chamber
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arXiv:2512.24837v1 Announce Type: new Abstract: In this paper, we present a Time Projection Chamber (TPC) system for low-background beta radiation measurements. The system consists of a TPC with two-dimensional-strip readout Micromegas and an anti-coincidence detector with readout pads for cosmic ray veto. The detector system utilize an AGET-based waveform sampling system for data acquisition. The beta detection capability of the system was verified through experimental test using $^{90}$Sr beta source. Additionally, a dedicated simulation program based on Geant4 was developed to model the entire detection process, including responses to both the beta source and background radiation. Simulation results were compared with experimental data for both beta and background samples, showing good agreements. The simulation samples were utilized to optimize and train classification models for beta and background discrimination. By applying the selected model into test data, the system achieved a background rate of 0.49 $\rm cpm/cm^2$ while retaining more than 55% of $^{90}$Sr beta signals within a 7 cm diameter detection region. Further analysis revealed that approximately 70% of the background originates from environmental gamma radiation, while the remaining contribution mainly comes from intrinsic radioactivity of detector materials, particularly the FR-4 based field cage and readout plane. Based on the knowledge gained from the experiments and simulations, an optimization of the TPC system has been proposed, with simulation predicting a potential reduction of the background rate to 0.0012 $\rm cpm/cm^2$.
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https://arxiv.org/abs/2512.24837
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Academic Papers
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cf298b206134b7d2f51779bf5c22f084ecdf0db340d8fa2791663497e7a316e4
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2026-01-01T00:00:00-05:00
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Influence of Centre Body on the Dynamics of Isothermal Flow Swirl Combustor
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arXiv:2512.24844v1 Announce Type: new Abstract: This study examines the effect of centre-body geometry on the dynamics of an isothermal, non-reacting swirl combustor through computational fluid dynamics (CFD) simulations. Two different central body shapes were considered in a lab-scale combustor configuration, modelled as transient, incompressible flow using the SST k-omega turbulence model. The numerical model was validated against experimental velocity data from literature to ensure accuracy. Cross-spectral analysis techniques were employed to characterise the coherent dynamics of the flow, providing insight into the influence of geometry on unsteady swirl dynamics.
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https://arxiv.org/abs/2512.24844
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Academic Papers
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43dc4be80e7363fd5a7f7809603ac2c7ade6c240e0c136a53d3776dbbfdef8b6
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2026-01-01T00:00:00-05:00
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Generation of NIR and Visible Structured Light Beams with a Mechanical Long-Period Fiber Grating
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arXiv:2512.24846v1 Announce Type: new Abstract: This work presents the tunable generation of vortex, vector, and flat-top 1060-nm NIR beams in a few-mode fiber with a mechanical long-period fiber grating. By the variation of applied force on the fiber grating, the core mode to higher-order mode excitation can be adjusted. The manipulation of the beam transformation is achieved through the polarization control of the fiber eigenmodes and mode coupling efficiency. By precisely tuning the intensity ratio between fundamental and doughnut modes, we arrive at the generation of propagation-invariant vector flat-top beams for more than 5 m. Transverse optical field of 532-nm green light from frequency-doubled Nd-doped yttrium vanadate laser is manipulated and coupled into various intensity distributions in a few-mode fiber by using a mechanically induced long-period fiber grating. We show that the doughnut beam, the Mexican-hat beam, and the crater-lake beam can be generated from the input Gaussian beam via the coupling of the fundamental core mode to a series of co-propagating higher-order modes with properly applied forces and polarizations.
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https://arxiv.org/abs/2512.24846
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Academic Papers
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70922b2b5ccacc7de5666a5873d4e2c296f67e03a177b729663dab49c49e715f
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2026-01-01T00:00:00-05:00
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Latent Twins: A Framework for Scene Recognition and Fast Radiative Transfer Inversion in FORUM All-Sky Observations
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arXiv:2512.24865v1 Announce Type: new Abstract: The FORUM (Far-infrared Outgoing Radiation Understanding and Monitoring) mission will provide, for the first time, systematic far-infrared spectral measurements of Earth's outgoing radiation, enabling improved understanding of atmospheric processes and the radiation budget. Retrieving atmospheric states from these observations constitutes a high-dimensional, ill-posed inverse problem, particularly under cloudy-sky conditions where multiple-scattering effects are present. In this work, we develop a data-driven, physics-aware inversion framework for FORUM all-sky retrievals based on latent twins: coupled autoencoders for atmospheric states and spectra, combined with bidirectional latent-space mappings. A lightweight model-consistency correction ensures physically plausible cloud variable reconstructions. The resulting framework demonstrates potential for retrievals of atmospheric, cloud and surface variables, providing information that can serve as a prior, initial guess, or surrogate for computationally expensive full-physics inversion methods. It also enables robust scene classification and near-instantaneous inference, making it suitable for operational near-real-time applications. We demonstrate its performance on synthetic FORUM-like data and discuss implications for future data assimilation and climate studies.
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https://arxiv.org/abs/2512.24865
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Academic Papers
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17459fe4cc6579395179e2b715666bfe4c754a0ae6f79b39f2bdd11cabd08738
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2026-01-01T00:00:00-05:00
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Variational phase-field modeling of fracture and fatigue in shape memory alloys
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arXiv:2512.24871v1 Announce Type: new Abstract: We propose a novel variational phase-field model for fracture and fatigue in pseudoelastic shape memory alloys (SMAs). The model, developed in a one-dimensional setting, builds upon the Auricchio-Petrini constitutive formulation for SMAs and couples damage evolution with phase transformation. We study analytically and numerically the homogeneous and localization responses of a bar under both monotonic and cyclic loading, and we investigate various macroscopic behaviors by tuning the constitutive parameters. A key feature of the model is the introduction of a transformation strain limit, beyond which the material is fully martensitic and behaves elastically. This leads to a distinctive behavior in which the region of localized damage widens, yielding a delay of fracture. The capability of the model to predict the fatigue performance is demonstrated by simulating the uniaxial response of Ni-Ti multi-wire samples under different loading conditions. The results show promising agreement with experimental fatigue life data, enabling the discrimination between safe and critical loading scenarios.
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https://arxiv.org/abs/2512.24871
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Academic Papers
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57671ced627c226d30907fa1c352bc391a3123305f57094ba2e035c4de9e73d6
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2026-01-01T00:00:00-05:00
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Hidden long-range correlations in the ion distribution at the graphite / [bmim][NTf$_2$] electrified interface
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arXiv:2512.24900v1 Announce Type: new Abstract: A capacitor consisting of the [bmim][NTf$_2$] ionic liquid (IL) confined in between planar graphite electrodes has been investigated by molecular dynamics based on an all-atom, unpolarizable force field. Structural and dynamical properties such as: (i) the density and orientation of the [bmim]$^+$ and [NTf$_2$]$^-$ ions throughout the capacitor; (ii) the electrostatic double layer at the electrode / electrolyte interface; (iii) the ions' mobility perpendicular and parallel to the graphite plates are determined as a function of the electrostatic charge of the capacitor, the concentration of absorbed water, the temperature and pressure. Grouping the [bmim]$^+$ and [NTf$_2$]$^-$ ions into neutral ion pairs reveals an intriguing ordering normal to the interface that is related to correlations among the dipole moments of the neutral ion pairs. These correlations might explain the observation of an anomalous Stark effect (Pockels effect) reported a few years ago in Langmuir, vol. 37, 5193-5201, (2021), and provides useful insight for the multitude of electro-chemical applications that involve electrode / ionic liquid interfaces.
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https://arxiv.org/abs/2512.24900
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434093b6456ba1b096b2fa95f26ba5625b31af2b767ce13b9213442591a25732
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2026-01-01T00:00:00-05:00
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Modelling the movements of organisms by stochastic theory in a comoving frame
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arXiv:2512.24937v1 Announce Type: new Abstract: Imagine you walk in a plane. You move by making a step of a certain length per time interval in a chosen direction. Repeating this process by randomly sampling step length and turning angle defines a two-dimensional random walk in what we call comoving frame coordinates. This is precisely how Ross and Pearson proposed to model the movements of organisms more than a century ago. Decades later their concept was generalised by including persistence leading to a correlated random walk, which became a popular model in Movement Ecology. In contrast, Langevin equations describing cell migration and used in active matter theory are typically formulated by position and velocity in a fixed Cartesian frame. In this article, we explore the transformation of stochastic Langevin dynamics from the Cartesian into the comoving frame. We show that the Ornstein-Uhlenbeck process for the Cartesian velocity of a walker can be transformed exactly into a stochastic process that is defined self-consistently in the comoving frame, thereby profoundly generalising correlated random walk models. This approach yields a general conceptual framework how to transform stochastic processes from the Cartesian into the comoving frame. Our theory paves the way to derive, invent and explore novel stochastic processes in the comoving frame for modelling the movements of organisms. It can also be applied to design novel stochastic dynamics for autonomously moving robots and drones.
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https://arxiv.org/abs/2512.24937
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75b5267133f4c4ddf57fafb9fcad568144f133ea2794688e060c41061bb8cffc
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2026-01-01T00:00:00-05:00
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Interaction of a Vortex Pair with a Polymeric Fluid Layer
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arXiv:2512.24944v1 Announce Type: new Abstract: The interaction of vortical structures with boundaries has been extensively studied in Newtonian fluids, where conditions such as no slip walls, free surfaces, or contaminated surfaces dictate whether vortices rebound, dissipate, or generate secondary structures. In this work, we investigate a related but fundamentally different problem: the interaction of a vortex pair with a finite, non uniform layer of polymeric fluid. Numerical simulations employing the finitely extensible nonlinear elastic Peterlin model are used to examine the effects of polymer concentration, relaxation time, polymer layer thickness, and maximum polymer extension on the evolution of kinetic energy and enstrophy. The results show that, while the polymeric fluid dissipates vortical motion, vortex polymer layer interactions can also generate new coherent structures. In particular, the formation of secondary and tertiary vortices coincides with transient increases in kinetic energy, a behavior absent in the Newtonian case. Unlike classical vortex boundary interactions, where the primary vortex survives, we find that under certain conditions it completely dissipates upon interaction with the polymer layer. These findings emphasize that fluids with non-uniform polymer concentrations, act not only as dissipative agents but also as sources of vorticity, extending the traditional view of polymer induced drag reduction and providing new insight into vortex polymer interactions.
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https://arxiv.org/abs/2512.24944
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d9df23f9169b2e61e4f1471acddb8744d9658a5e8b36efeca6ee8f684faaa774
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2026-01-01T00:00:00-05:00
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Simulations of two-dimensional single-mode Rayleigh-Taylor Instability using front-tracking/ghost-fluid method: comparison to experiments and theory
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arXiv:2512.24949v1 Announce Type: new Abstract: Two-dimensional single-mode Rayleigh-Taylor Instability (RTI) is simulated using an accurate and robust front-tracking/ghost-fluid method (FT/GFM) with high-order weighted essentially non-oscillatory (WENO) scheme. We compare our numerical results with the single-mode RTI experiments of Renoult, Rosenblatt and Carles (2015). The time evolution of the interface between two immiscible fluids and the effects of surface tension on the growth of the amplitude and asymmetry of the perturbed interface are examined for the initial wavelength 1 cm and the Atwood number A=0.29. The important features of RTI flows such as interface profiles, bubble/spike penetration and velocities show good agreement between experiments and simulations of immiscible fluids with surface tension. The velocity vector fields for the bubble and spike in the linear and nonlinear regimes are consistent with the theory for the single wavelength perturbation.
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https://arxiv.org/abs/2512.24949
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ae35d3635004a4ed20b121bd2f326250babdf4c202ce831c23e5d5a07d59ece8
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2026-01-01T00:00:00-05:00
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Random Batch Sum-of-Gaussians Method for Molecular Dynamics of Born-Mayer-Huggins Systems
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arXiv:2512.24970v1 Announce Type: new Abstract: The Born-Mayer-Huggins (BMH) potential, which combines Coulomb interactions with dispersion and short-range exponential repulsion, is widely used for ionic materials such as molten salts. However, large-scale molecular dynamics simulations of BMH systems are often limited by computation, communication, and memory costs. We recently proposed the random batch sum-of-Gaussians (RBSOG) method, which accelerates Coulomb calculations by using a sum-of-Gaussians (SOG) decomposition to split the potential into short- and long-range parts and by applying importance sampling in Fourier space for the long-range part. In this work, we extend the RBSOG to BMH systems and incorporate a random batch list (RBL) scheme to further accelerate the short-range part, yielding a unified framework for efficient simulations with the BMH potential. The combination of the SOG decomposition and the RBL enables an efficient and scalable treatment of both long- and short-range interactions in BMH system, particularly the RBL well handles the medium-range exponential repulsion and dispersion by the random batch neighbor list. Error estimate is provided to show the theoretical convergence of the RBL force. We evaluate the framework on molten NaCl and mixed alkali halide with up to $5\times10^6$ atoms on $2048$ CPU cores. Compared to the Ewald-based particle-particle particle-mesh method and the RBSOG-only method, our method achieves approximately $4\sim10\times$ and $2\times$ speedups while using $1000$ cores, respectively, under the same level of structural and thermodynamic accuracy and with a reduced memory usage. These results demonstrate the attractive performance of our method in accuracy and scalability for MD simulations with long-range interactions.
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https://arxiv.org/abs/2512.24970
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286349cb92d208a80bf0dbb1d2c066b83bfb91d6ffdde254f4804dac59c5bf4b
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2026-01-01T00:00:00-05:00
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Optical Spiking Neural Networks via Rogue-Wave Statistics
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arXiv:2512.24983v1 Announce Type: new Abstract: Optical computing could reduce the energy cost of artificial intelligence by leveraging the parallelism and propagation speed of light. However, implementing nonlinear activation, essential for machine learning, remains challenging in low-power optical systems dominated by linear wave physics. Here, we introduce an optical spiking neural network that uses optical rogue-wave statistics as a programmable firing mechanism. By establishing a homomorphism between free-space diffraction and neuronal integration, we demonstrate that phase-engineered caustics enable robust, passive thresholding: sparse spatial spikes emerge when the local intensity exceeds a significant-intensity rogue-wave criterion. Using a physics-informed digital twin, we optimize granular phase masks to deterministically concentrate energy into targeted detector regions, enabling end-to-end co-design of the optical transformation and a lightweight electronic readout. We experimentally validate the approach on BreastMNIST and Olivetti Faces, achieving accuracies of 82.45\% and 95.00\%, respectively, competitive with standard digital baselines. These results demonstrate that extreme-wave phenomena, often treated as deleterious fluctuations, can be harnessed as structural nonlinearity for scalable, energy-efficient neuromorphic photonic inference.
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https://arxiv.org/abs/2512.24983
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746ccdc2146c7b26e41bbc16e42d997dd9b0e6cbd47686bc39bfff0f9a57ee6e
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2026-01-01T00:00:00-05:00
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Noise resilient real-time phase imaging via undetected light
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arXiv:2512.24993v1 Announce Type: new Abstract: Quantum imaging with undetected light has recently emerged as a technique in which quantum correlations and nonlinear interferometry are combined to decouple illumination and detection paths. This approach has been more recently extended and combined with digital phase-shifting holography and off-axis holography to extract both the amplitude and phase information of a sample relying on single-photon interference. Despite these advantages, implementing the technique in real-world scenarios where the observed system is subject to environmental noise and dynamic variations remains challenging. The primary limitation lies in the inability of quantum imaging systems to retrieve object information in real time under high-noise conditions. Here, we experimentally demonstrate real-time amplitude and phase imaging in noisy environments, building upon our previous implementation of quantum off-axis holography. Our results demonstrate real-time imaging at acquisition rates up to 4~Hz, even when the noise level exceeds the signal by an order of magnitude.
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https://arxiv.org/abs/2512.24993
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4520a39c7725801de58a380610a49f66c11a0220ed7729896dcaf46a07fe0b04
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2026-01-01T00:00:00-05:00
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Fast Poisson brackets and constraint algebras in canonical gravity
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arXiv:2512.25007v1 Announce Type: new Abstract: In the study of alternative or extended theories of gravity, Dirac's Hamiltonian constraint algorithm is invaluable for enumerating the propagating modes and gauge symmetries. For gravity, this canonical approach is frequently applied as a means for finding pathologies such as strongly coupled modes; more generally it facilitates the reconstruction of gauge symmetries and the quantization of gauge theories. For gravity, however, the algorithm can become notoriously arduous to implement. We present a simple computer algebra package for efficiently computing Poisson brackets and reconstructing constraint algebras. The tools are stress-tested against pure general relativity and modified gravity, including the order reduction of general relativity at two loops.
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https://arxiv.org/abs/2512.25007
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9361b722b039ab28ad0634a8ddb9017bd362c80e1837b1de14ec3f592dfcf06b
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2026-01-01T00:00:00-05:00
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Detector Response Matrices, Effective Areas, and Flash-Effective Areas for Radiation Detectors
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arXiv:2512.25021v1 Announce Type: new Abstract: A Detector Response Matrix (DRM) is a discrete representation of an instrument's Detector Response Function (DRF), which quantifies how many discrete energy depositions occur in a detector volume for a given distribution of particles incident on the detector. For simple radiation detectors that can count such energy depositions (such as scintillators, Proportional Counter Tubes (PCTs), etc), we consider the ideal counting DRF, $\mathbf{G}_\varphi (E_\mathrm{in}, E_\mathrm{dep})$, which relates the detector's counting histogram (number of energy depositions within a given channel) to an incident particles characterization, $\varphi$ (e.g. incident flux, fluence, intensity). From the counting DRF we can derive the counting DRM, the effective area, and the flash effective area (which measures the total energy deposited in the detector from a large, instantaneous fluence).
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https://arxiv.org/abs/2512.25021
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91c2d794f04d28ad8e62c93a80bc33adea6f4048273929853dc50302967179c4
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2026-01-01T00:00:00-05:00
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On Nonlinear Inertial Transformations
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arXiv:2512.25024v1 Announce Type: new Abstract: It is often assumed that the most general transformation between two inertial reference frames is affine linear in their Cartesian coordinates, an assumption which is however not true. We provide a complete derivation of the most general inertial frame transformation, which is indeed nonlinear; along the way, we shall find that the conditions of preserving the Law of Inertia take the form of Schwarzian differential equations, providing perhaps the simplest possible physics setting in which the Schwarzian derivative appears. We then demonstrate that the most general such inertial transformation which further preserves the speed of light in all directions is, however, still affine linear. Physically, this paper may be viewed as a reduction of the number of postulates needed to uniquely specify special relativity by one, as well as a proof that inertial transformations automatically imbue spacetime with a vector space structure, albeit in one higher dimension than might be expected. Mathematically, this paper may be viewed as a derivation of the higher-dimensional analog of the Schwarzian differential equation and its most general solution.
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https://arxiv.org/abs/2512.25024
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3a3dd91ed7d2546685658e233601eb2632bfd6114acd2fab712782210be64757
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2026-01-01T00:00:00-05:00
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Computational Analysis of Disease Progression in Pediatric Pulmonary Arterial Hypertension
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arXiv:2512.25027v1 Announce Type: new Abstract: Pulmonary arterial hypertension (PAH) is a progressive cardiopulmonary disease that leads to increased pulmonary pressures, vascular remodeling, and eventual right ventricular (RV) failure. Pediatric PAH remains understudied due to limited data and the lack of targeted diagnostic and therapeutic strategies. In this study, we developed and calibrated multi-scale, patient-specific cardiovascular models for four pediatric PAH patients using longitudinal MRI and catheterization data collected approximately two years apart. Using the CRIMSON simulation framework, we coupled three-dimensional fluid-structure interaction (FSI) models of the pulmonary arteries with zero-dimensional (0D) lumped-parameter heart and Windkessel models to simulate patient hemodynamics. An automated Python-based optimizer was developed to calibrate boundary conditions by minimizing discrepancies between simulated and clinical metrics, reducing calibration time from weeks to days. Model-derived metrics such as arterial stiffness, pulse wave velocity, resistance, and compliance were found to align with clinical indicators of disease severity and progression. Our findings demonstrate that computational modeling can non-invasively capture patient-specific hemodynamic adaptation over time, offering a promising tool for monitoring pediatric PAH and informing future treatment strategies.
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https://arxiv.org/abs/2512.25027
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a788fd42f1a8371f52613a1344dcf6821e52f9a9146b577bbf4088474f30f024
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2026-01-01T00:00:00-05:00
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Extreme nonlinear optics in optical fibers
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arXiv:2512.25046v1 Announce Type: new Abstract: This paper reviews the field of extreme nonlinear optics in optical fibers, highlighting key phenomena and advancements. It discusses multiple ionization effects caused by femtosecond laser pulses that generate plasma and induce permanent material modifications, as well as plasma luminescence and its dependence on material imperfections. The formation and dynamics of plasma filaments, including helical structures, are explored, along with the rainbow spiral emission pattern useful in communications and particle manipulation. The review covers the generation of spatial-temporal waves, supercontinuum broadening, and advanced modeling techniques, such as multimode unidirectional pulse propagation equations for describing optical pulse evolution. Experimental demonstrations involving discretized conical waves and supercontinuum generation optimization are detailed. The paper emphasizes the unique capabilities of photonic crystal fibers, especially hollow-core variants, in achieving broad supercontinua and Raman frequency combs, ultrashort pulse compression, high-harmonic generation, plasma formation, and nonclassical light production. Our outlook highlights ongoing research into spatiotemporal helicon waves, ultrashort pulse propagation, vacuum ultraviolet and mid-infrared supercontinuum generation, and innovative fiber technologies. Future directions focus on enhancing fiber performance, understanding multimodal wave dynamics, and expanding applications in telecommunications, sensing, and quantum science.
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https://arxiv.org/abs/2512.25046
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b7fa85084a26c2e191284df614a0e6992865be0f05ebacfc61929aee22c9fa0e
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2026-01-01T00:00:00-05:00
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All optical Lithography for Spatiotemporal Patterning of Azopolymer Microreliefs
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arXiv:2512.25048v1 Announce Type: new Abstract: Microstructured surfaces are central to photonics, biointerfaces, and functional coatings, yet they are typically fabricated through multi-step lithographic workflows requiring masks or molds and post-processing. Azopolymers provide an alternative route by converting structured optical fields into surface reliefs via light-induced mass migration, but existing approaches have been limited to smooth, shallow, and engraving-like topographies produced from a flat film. Here we introduce an all-optical, maskless, fully digital lithography platform that exploits engineered darkness within computer-generated holograms to spatially localize inward mass transport and directly produce positive, protruding microreliefs. We show that isolated and array of micro-bumps can be generated from pristine flat azopolymer films in a single writing step, and we introduce spatiotemporal control through sequential tailored illumination to reshape microrelief profiles, enabling flattened-top micropillars, programmable array shapes and arrangements, and free-form continuous microrelief designs. Hierarchical microarchitectures are also demonstrated by extending the concept of multi-step illumination sequences. As functional demonstrations, we realize multi-focus microlenses and quasi-square diffraction gratings with enhanced 1st-order efficiencies. Finally, we leverage azopolymer reconfigurability to implement write-erase-rewrite cycles that reset and repurpose the same surface region for distinct micropatterns, enabling rewritable surfaces and reprogrammable master templates for replication. Overall, this work establishes a scalable spatiotemporal strategy for on-demand, all-optical microfabrication and reprogramming of structured surfaces, where spatial and temporal degrees of freedom of holographic patterns intermix to produce advanced patterning capabilities.
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https://arxiv.org/abs/2512.25048
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Academic Papers
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31919d315c1f5af8015e4f9e65b594407201faa283a333a9cd757a3c88053ae9
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2026-01-01T00:00:00-05:00
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Arithmetic with spatiotemporal optical vortex of integer and fractional topological charges
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arXiv:2512.25049v1 Announce Type: new Abstract: Spatiotemporal optical vortices carry transverse orbital angular momentum (t-OAM), which give rise to spatiotemporal topological charge (ST-TC). To unleash the full potential of t-OAM in expanding the capacity of communication and computing, we demonstrate the first optical information-processing pipeline capable of performing addition and subtraction on ST-TC values, regardless of whether they are integer or fractional. Additionally, we established a readout method for those mathematical operations through imaging spectral analysis, providing a robust optical basis toward arithmetic operations and verification. These new capabilities mark crucial advancements toward full arithmetic operations on the ST-TC of light for bosonic state computation and information processing.
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https://arxiv.org/abs/2512.25049
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fe195b22f7382b542cf51488a3c2cca3219e874fd7cc710f5455d72fb9c104d8
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2026-01-01T00:00:00-05:00
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The Logical Structure of Physical Laws: A Fixed Point Reconstruction
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arXiv:2512.25057v1 Announce Type: new Abstract: We formalise the self referential definition of physical laws using monotone operators on a lattice of theories, resolving the pathologies of naive set theoretic formulations. By invoking Tarski fixed point theorem, we identify physical theories as least fixed points of admissibility constraints derived from Galois connections. We demonstrate that QED and General Relativity can be represented in such a logical structure with respect to their symmetry and locality principles.
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https://arxiv.org/abs/2512.25057
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b0f925311df8d311ea3df8173aca82617e79c2a20b97c07b98bde558398ba2ee
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2026-01-01T00:00:00-05:00
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NeuralCrop: Combining physics and machine learning for improved crop yield predictions
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arXiv:2512.20177v1 Announce Type: cross Abstract: Global gridded crop models (GGCMs) simulate daily crop growth by explicitly representing key biophysical processes and project end-of-season yield time series. They are a primary tool to quantify the impacts of climate change on agricultural productivity and assess associated risks for food security. Despite decades of development, state-of-the-art GGCMs still have substantial uncertainties in simulating complex biophysical processes due to limited process understanding. Recently, machine learning approaches trained on observational data have shown great potential in crop yield predictions. However, these models have not demonstrated improved performance over classical GGCMs and are not suitable for simulating crop yields under changing climate conditions due to problems in generalizing outside their training distributions. Here we introduce NeuralCrop, a hybrid GGCM that combines the strengths of an advanced process-based GGCM, resolving important processes explicitly, with data-driven machine learning components. The model is first trained to emulate a competitive GGCM before it is fine-tuned on observational data. We show that NeuralCrop outperforms state-of-the-art GGCMs across site-level and large-scale cropping regions. Across moisture conditions, NeuralCrop reproduces the interannual yield anomalies in European wheat regions and the US Corn Belt more accurately during the period from 2000 to 2019 with particularly strong improvements under drought extremes. When generalizing to conditions unseen during training, NeuralCrop continues to make robust projections, while pure machine learning models exhibit substantial performance degradation. Our results show that our hybrid crop modelling approach offers overall improved crop modeling and more reliable yield projections under climate change and intensifying extreme weather conditions.
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https://arxiv.org/abs/2512.20177
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8b505fc7fd0740a7cfb1c3b8c8ca5b3589974aa03d4ae98ae71aa2907e516221
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2026-01-01T00:00:00-05:00
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Quantization of Physical Interaction Strengths via Singular Moduli
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arXiv:2512.23741v1 Announce Type: cross Abstract: Since the 2019 redefinition of the SI units, precision metrology has sought to anchor all physical quantities to fundamental constants and integer invariants. While the optical frequency comb revolutionized timekeeping by discretizing the continuum of light into countable teeth, and the Quantum Hall Effect standardized resistance via topological invariants, a comparable standard for interaction strength remains elusive. Currently, measuring the coupling constant ($g$) between quantum systems is an estimation problem, inherently subject to drift, noise, and fabrication variance. Here, we introduce Interaction Metrology, a protocol that transforms the measurement of coupling strengths from an analog estimation into a topological counting problem. By engineering a specific class of algebraic catastrophe -- the Unimodal $X_9$ singularity -- in a driven-dissipative lattice, we prove that the system's interaction moduli are topologically forced to take discrete, quantized values, forming a "Geometric $k$-Comb." We derive the universality class of this quantization, showing that it arises from the discrepancy between the Milnor ($\mu$) and Tjurina ($\tau$) numbers of the effective potential, a strictly non-Hermitian effect forbidden in standard quantum mechanics. Finally, we provide an ab-initio blueprint for a silicon nitride implementation, demonstrating that this quantization is robust against disorder levels exceeding current foundry tolerances. This discovery establishes a universal standard for force sensing and quantum logic gates, enabling the calibration of interaction strengths with topological certainty.
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https://arxiv.org/abs/2512.23741
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d760ee88a690b298fbe69b9537fb5a6426a8fb66f0f12aac11c532a9d7b8dd9d
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2026-01-01T00:00:00-05:00
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Sheaf-theoretic representation of the proteolipid code
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arXiv:2512.23784v1 Announce Type: cross Abstract: Membrane particles such as proteins and lipids organize into zones that perform unique functions. Here, I introduce a topological and category-theoretic framework to represent particle and zone intra-scale interactions and inter-scale coupling. This involves carefully demarcating between different presheaf- or sheaf-assigned data levels to preserve functorial structure and account for particle and zone generalized poses. The framework can accommodate Hamiltonian mechanics, enabling dynamical modeling. This amounts to a versatile mathematical formalism for membrane structure and multiscale coupling.
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https://arxiv.org/abs/2512.23784
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58a32eec7e85d3fba694d77cf2f46821268de10126685433440fd0e35b097849
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2026-01-01T00:00:00-05:00
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Geometric View of One-Dimensional Quantum Mechanics
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arXiv:2512.23923v1 Announce Type: cross Abstract: We apply De Haro's Geometric View of Theories to one of the simplest quantum systems: a spinless particle on a line and on a circle. The classical phase space M = T*Q is taken as the base of a trivial Hilbert bundle E ~ M x H, and the familiar position and momentum representations are realised as different global trivialisations of this bundle. The Fourier transform appears as a fibrewise unitary transition function, so that the standard position-momentum duality is made precise as a change of coordinates on a single geometric object. For the circle, we also discuss twisted boundary conditions and show how a twist parameter can be incorporated either as a fixed boundary condition or as a base coordinate, in which case it gives rise to a flat U(H)-connection with nontrivial holonomy. These examples provide a concrete illustration of how the Geometric View organises quantum-mechanical representations and dualities in geometric terms.
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https://arxiv.org/abs/2512.23923
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fd5320a7e6a7ae73f305471c9d0b943abebccea0927f723cdb80d1673a826773
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2026-01-01T00:00:00-05:00
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Towards Quantum Machine Learning of Lattice Boltzmann Collision Operators for Fluid Dynamic Simulations
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arXiv:2512.23991v1 Announce Type: cross Abstract: We attempt the use of a unitary operator to approximate the lattice Boltzmann collision operator. We use a modified amplitude encoding to bypass the renormalization that would have required classical processing at every step (thus eroding any quantum advantage to be had). We describe the hard-wiring of the lattice Boltzmann symmetries into the quantum circuit and show that, for the specific case of the cavity flow, approximating the nonlinear system is limited to low velocities. These findings may help us understand better the possibilities of nonlinear simulations on a quantum computer, and also pave the way for a discussion on how quantum machine learning might be harnessed to address more complex problems.
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https://arxiv.org/abs/2512.23991
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90c78d800b786fe1f2a51e4193147832f824a59041c50c8953c7e693d8ae2e37
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2026-01-01T00:00:00-05:00
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5-GHz chip-based quantum key distribution with 1Mbps secure key rate over 150 km
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arXiv:2512.24094v1 Announce Type: cross Abstract: Quantum key distribution (QKD) enables secure communication by harnessing the fundamental principles of quantum physics, which inherently guarantee information-theoretic security and intrinsic resistance to quantum computing attacks. However, the secure key rate of QKD typically decreases exponentially with increasing channel distance. In this work, by developing a novel polarization-state preparation method, an ultra-low time-jitter laser source and superconducting nanowire single-photon detectors, we demonstrate a 5-GHz integrated QKD system featuring ultra-low quantum bit error rates (QBERs). The system achieves secure key rates of 1.076 Mbps at 150 km and 105 kbps at 200 km over standard single-mode fiber channels, respectively. Our system substantially enhances the secure key rate, enabling high-resolution video calls with one-time-pad encryption over intercity backbone QKD links. This work represents a significant step forward in the development of high-performance practical QKD systems.
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https://arxiv.org/abs/2512.24094
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91446537d5526d38eca70747e8fe2f85e573cf78d95fe1164425ee155964bec5
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2026-01-01T00:00:00-05:00
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Soft x-rays with Orbital Angular Momentum for resonant scattering experiments at the SOLEIL synchrotron
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arXiv:2512.24191v1 Announce Type: cross Abstract: The paper presents a comprehensive description of a new setup implemented and commissioned at the SEXTANTS beamline of the SOLEIL synchrotron for absorption and scattering experiments with x-ray beams carrying an orbital angular momentum, also known as twisted x-ray beams. Two alternative methods have been implemented, based on the use of either spiral zone plates or fork gratings devices, and we show how they can be used for both defining and assessing the orbital angular momentum of an x-ray beam. We show also how multiple devices can be used in sequence to define an integer arithmetic of the orbital angular momentum of the final x-ray beam. Finally, we report the results of the first resonant scattering pilot experiments in transmission and reflection mode, intended to assess the feasibility of future users measurements. The availability of twisted soft x-rays complements the range of experimental techniques in elastic, resonant and coherent scattering available at the SEXTANTS beamline of the SOLEIL synchrotron.
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https://arxiv.org/abs/2512.24191
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f9bdffb183838f468072c7964709ee97a465300dd93a2bb84b794424bd181515
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2026-01-01T00:00:00-05:00
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A short technical comment on Bub's There is No Quantum World (arXiv:2512.18400v2) and a brief remark on related Grangier's reply (arXiv:2512.22965v1)
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arXiv:2512.24198v1 Announce Type: cross Abstract: This note is a friendly technical check of Jeffrey Bub's There is No Quantum World (arXiv:2512.18400v2). I flag one unambiguous mathematical slip (a cardinality identity that implicitly assumes the Continuum Hypothesis) and then point out a few places where the discussion of infinite tensor products, ``sectorization,'' and measurement updates would benefit from sharper wording. Nothing here is meant as a critique of Bub's interpretive goals; the aim is simply to separate what is mathematically forced from what depends on choices of algebra, representation, or philosophical stance. I end with a short remark on Philippe Grangier's reply (arXiv:2512.22965v1).
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https://arxiv.org/abs/2512.24198
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45fa0935ec157f0ad42252a09f1a25c2022e078c77aa5c74c7d428eadf8c68f0
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2026-01-01T00:00:00-05:00
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Extending the Growth Temperature-N Concentration Regime Through Pd Doping in Fe4N Thin Films
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arXiv:2512.24208v1 Announce Type: cross Abstract: Fe4N is a well-known anti-perovskite compound exhibiting high magnetization, high chemical stability, low coercivity, high Curie temperature, and high spin-polarization ratio. Therefore, it is a viable candidate for applications in spintronic and magnetic storage devices. However, the Fe4N phase is formed in a narrow substrate temperature (Ts)-N concentration (Nc) regime in the phase diagram of Fe-N. It has been observed that a slight N deficiency will lead to impurity of alpha-Fe, and some N efficiency would result in epsilon-Fe3N phase. Through this work, it has been demonstrated that the doping of Pd can be suitably utilized to extend the Ts-Nc regime for the growth of Fe4N thin films. EXAFS analysis indicate that Pd atoms are substituting corner Fe atoms. Magnetization measurements reveal that the saturation magnetization reduces nominally with Pd doping up to 13 at.%. Therefore, it is foreseen that Pd doping is effective in extending the Fe4N phase formation regime without a significant impact on its structural, electronic, and magnetic properties.
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https://arxiv.org/abs/2512.24208
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f762554bec3546899ecf5bce6ed9fa73c81865e62bfc25ed23211bb38de6cbee
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2026-01-01T00:00:00-05:00
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Tritium accumulation and ozone decontamination of tungsten and beryllium
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arXiv:2512.24256v1 Announce Type: cross Abstract: Tritium adsorption on surfaces creates a variety of issues, ranging from the fields of fusion applications to small and large-scale laboratory experiments using tritium. The extent to which tritium accumulates on surfaces is generally material-dependent and must be determined through experiments. Additionally, this surface contamination necessitates the implementation of appropriate decontamination procedures, preferably in-situ. A suitable method could be exposure to ozone during UV irradiation. However, it is currently not known if both components are necessary for the decontamination. At Tritium Laboratory Karlsruhe, both questions on contamination and decontamination can be addressed using a single experimental setup. With this, it is possible to expose solid samples to gaseous tritium to measure the temporal activity evolution. Furthermore, the system can be filled with dry air, and dry air containing ozone to explore their decontamination effect. Both measurement modes were applied to beryllium and tungsten samples, which were chosen for their relevance in fusion. The beryllium surface was observed to accumulate tritium more than four times faster than tungsten when exposed to gaseous tritium. Concerning the decontamination, without simultaneous UV irradiation, exposure to ozone did not have any distinct effect on the surface activity compared to simply using dry air. This leads to the conclusion that UV illumination of the surfaces is required to achieve a significant decontamination factor.
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https://arxiv.org/abs/2512.24256
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3e44ff1e9530cafd6080ee53efedec352deb792e02852e904180a285bf12ba6a
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2026-01-01T00:00:00-05:00
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Using NV centers in diamond to detect DC to very-low frequency magnetic fields
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arXiv:2512.24273v1 Announce Type: cross Abstract: In this work we present a compact and portable tabletop magnetometer that utilizes negatively charged nitrogen-vacancy (NV) centers in diamond. The magnetometer is operated using a dual microwave resonance detection approach in combination with an optically detected magnetic resonance (ODMR) technique (mitigating drifts in results due to changes of the diamond temperature), capable of simultaneously exciting and registering two ODMR transitions. The experimentally measured magnetic field noise-floor is $\approx 2.3~\textrm{nT}\sqrt{\textrm{Hz}}$ while the calculated shot-noise-limited magnetic field sensitivity is $\approx 585~\textrm{pT}\sqrt{\textrm{Hz}}$ when excited with a continuous wave laser at 0.5~W. These results pave the way for realizing a simple set-up magnetometer for precise single axis magnetic field measurements for example for accurate electric current measurements for stabilization purposes and magnetic communication applications.
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https://arxiv.org/abs/2512.24273
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81969c95fdcd8760d00c09bd62ea6dba408d41fde13d9125ddd42c332870f399
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2026-01-01T00:00:00-05:00
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Assembling a Bose-Hubbard superfluid from tweezer-controlled single atoms
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arXiv:2512.24374v1 Announce Type: cross Abstract: Quantum simulation relies on the preparation and control of low-entropy many-body systems to reveal the behavior of classically intractable models. The development of new approaches for realizing such systems therefore represents a frontier in quantum science. Here we experimentally demonstrate a new protocol for generating ultracold, itinerant many-body states in a tunnel-coupled two-dimensional optical lattice. We do this by adiabatically connecting a near-ground-state-cooled array of up to 50 single strontium-86 atoms with a Bose-Hubbard superfluid. Through comparison with finite-temperature quantum-Monte-Carlo calculations, we estimate that the entropy per particle of the prepared many-body states is approximately $2 k_B$, and that the achieved temperatures are consistent with a significant superfluid fraction. This represents the first time that itinerant many-body systems have been prepared from rearranged atoms, opening the door to bottom-up assembly of a wide range of neutral-atom and molecular systems.
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https://arxiv.org/abs/2512.24374
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c8f3d8c24aad4938bc871108969a84a52d6865038e152d49bccc0b4bf253a055
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2026-01-01T00:00:00-05:00
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Turbulence-Driven Corrugation of Collisionless Fast-Magnetosonic Shocks
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arXiv:2512.24425v1 Announce Type: cross Abstract: Collisionless fast-magnetosonic shocks are often treated as smooth, planar boundaries, yet observations point to organized corrugation of the shock surface. A plausible driver is upstream turbulence. Broadband fluctuations arriving at the front can continually wrinkle it, changing the local shock geometry and, in turn, conditions for particle injection and radiation. We develop a linear-MHD formulation that treats the shock as a moving interface rather than a fixed boundary. In this approach the shock response can be summarized by an effective impedance determined by the Rankine-Hugoniot base state and the shock geometry, while the upstream turbulence enters only through its statistics. This provides a practical mapping from an assumed incident spectrum to the corrugation amplitude, its drift along the surface, and a coherence scale set by weak damping or leakage. The response is largest when the transmitted downstream fast mode propagates nearly parallel to the shock in the shock frame, which produces a Lorentzian-type enhancement controlled by the downstream normal group speed. We examine how compression, plasma $\beta$, and obliquity affect these corrugation properties and discuss implications for fine structure in heliospheric and supernova-remnant shock emission.
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https://arxiv.org/abs/2512.24425
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3dc86fac36997abf5168ce98f74ad5fff5a27d8418bc1a298277f1029a680ba2
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2026-01-01T00:00:00-05:00
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Epigenetic Control and Reprogramming-Induced Potential Landscapes of Gene Regulatory Networks: A Quantitative Theoretical Approach
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arXiv:2512.24427v1 Announce Type: cross Abstract: We develop an extended Dynamical Mean Field Theory framework to analyze gene regulatory networks (GRNs) incorporating epigenetic modifications. Building on the Hopfield network model analogy to spin glass systems, our approach introduces dynamic terms representing DNA methylation and histone modification to capture their regulatory influence on gene expression. The resulting formulation reduces high-dimensional GRN dynamics to effective stochastic equations, enabling the characterization of both stable and oscillatory states in epigenetically regulated systems. This framework provides a tractable and quantitative method for linking gene regulatory dynamics with epigenetic control, offering new theoretical insights into developmental processes and cell fate decisions.
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https://arxiv.org/abs/2512.24427
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e81fa43cf23aa6064cda5605fe466e32ccab7774464a4c1890e9886b763f89e4
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2026-01-01T00:00:00-05:00
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Picture an Astronomer: Best Practices for Retaining Talent in Astrophysics
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arXiv:2512.24465v1 Announce Type: cross Abstract: Women are consistently underrepresented in astrophysics yet are simultaneously subject to disproportionate attrition at every career stage. This disparity between demonstrated efficacy in job performance and ultimate career outcome was the primary motivation for the Picture an Astronomer series, which included both targeted public outreach to increase representation of women in astrophysics and high-level, solution-oriented discussions among professional astronomers. In March 2025, more than 200 astronomers came together in a hybrid-format symposium focused on the state of the field for female scientists, combining scientific exchange with discussions of policies and practices to strengthen retention of talent in the field. This white paper is the result of those discussions, offering a wide range of recommendations developed in the context of gendered attrition in astrophysics but which ultimately support a healthier climate for all scientists alike.
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https://arxiv.org/abs/2512.24465
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a83be75d2bb79959d8f9087316c8f09d0d6ac2b9a6defdf6979a2e3af3fa479d
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2026-01-01T00:00:00-05:00
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Dynamics of Interfacial Diffusion Control in Amphiphilic Lipid-Coated Micro-Particles for Stochastic Release Systems
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arXiv:2512.24566v1 Announce Type: cross Abstract: The release of hydrophilic solutes from micron scale particulate formulations can be understood as an interfacial transport problem in which diffusion across a heterogeneous amphiphilic coating competes with dissolution and convective removal in the surrounding medium. Here we reinterpret a glycerin fatty acid ester (GFAE) coated thiamine (vitamin B1) micro particle formulation as a condensed matter system: a soft matter core shell geometry whose effective permeability is set by the nanoscale organization of amphiphilic lipids at the interface. Using in vivo time course serum measurements in mice as a proxy for a stochastic sink, we compare the coated formulation (UTEV) with a composition matched uncoated comparator (UMFG). Early time systemic appearance is similar, whereas late time levels are enhanced for the coated particles, implying a reduced effective interfacial diffusivity and a broadened release-time distribution. We discuss the results in terms of diffusion barrier physics, heterogeneous interfacial energetics, and coarse grained transport models that map microstructural coating parameters to macroscopic persistence (AUC).
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https://arxiv.org/abs/2512.24566
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bab5181c151ac4c81129e640ec03854e68cd118d98c98b7c242243edbba2ef0d
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2026-01-01T00:00:00-05:00
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Band Structure and Dynamics of Single Photons in Atomic Lattices
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arXiv:2512.24596v1 Announce Type: cross Abstract: We present a framework to investigate the collective properties of atomic lattices in one, two, and three dimensions. We analyze the single-photon band structure and associated atomic decay rates, revealing a fundamental dependence on dimensionality. One- and two-dimensional arrays are shown to be inherently radiative, exhibiting band gaps and decay rates that oscillate between superradiant and subradiant regimes, as a function of lattice spacing. In contrast, three-dimensional lattices are found to be fundamentally non-radiative due to the inhibition of spontaneous emission, with decay only at discrete Bragg resonances. Furthermore, we demonstrate that this structural difference dictates the system dynamics, which crosses over from dissipative decay in lower dimensions to coherent transport in three dimensions. Our results provide insight into cooperative effects in atomic arrays at the single-photon level.
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https://arxiv.org/abs/2512.24596
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70b935e82c17b94f5f64226a5677e737554f777ed1f1ddaaee004d2bd26338d2
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2026-01-01T00:00:00-05:00
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Volcano Architecture for Scalable Quantum Processor Units
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arXiv:2512.24626v1 Announce Type: cross Abstract: Quantum information processing platforms based on array of matter qubits, such as neutral atoms, trapped ions, and quantum dots, face significant challenges in scalable addressing and readout as system sizes increase. Here, we propose the "Volcano" architecture that establishes a new quantum processing unit implementation method based on optical channel mapping on a arbitrarily arranged static qubit array. To support the feasibility of Volcano architecture, we show a proof-of-principle demonstration by employing a photonic chip that leverages custom-designed three-dimensional waveguide structures to transform one-dimensional beam arrays into arbitrary two-dimensional output patterns matching qubit array geometries. We demonstrate parallel and independent control of 49-channel with negligible crosstalk and high uniformity. This architecture addresses the challenges in scaling up quantum processors, including both the classical link for parallel qubit control and the quantum link for efficient photon collection, and holds the potential for interfacing with neutral atom arrays and trapped ion crystals, as well as networking of heterogeneous quantum systems.
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https://arxiv.org/abs/2512.24626
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4374f620c269a57727008b8bb01e710390e86bb46f1055cb0255d9d3a4e07208
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2026-01-01T00:00:00-05:00
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Upscaling from ab initio atomistic simulations to electrode scale: The case of manganese hexacyanoferrate, a cathode material for Na-ion batteries
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arXiv:2512.24816v1 Announce Type: cross Abstract: We present a generalizable scale-bridging computational framework that enables predictive modeling of insertion-type electrode materials from atomistic to device scales. Applied to sodium manganese hexacyanoferrate, a promising cathode material for grid-scale sodium-ion batteries, our methodology employs an active-learning strategy to train a Moment Tensor Potential through iterative hybrid grand-canonical Monte Carlo--molecular dynamics sampling, robustly capturing configuration spaces at all sodiation levels. The resulting machine learning interatomic potential accurately reproduces experimental properties including volume expansion, operating voltage, and sodium concentration-dependent structural transformations, while revealing a four-order-of-magnitude difference in sodium diffusivity between the rhombohedral (sodium-rich) and tetragonal (sodium-poor) phases at 300 K. We directly compute all critical parameters -- temperature- and concentration-dependent diffusivities, interfacial and strain energies, and complete free-energy landscapes -- to feed them into pseudo-2D phase-field simulations that predict phase-boundary propagation and rate-dependent performances across electrode length scales. This multiscale workflow establishes a blueprint for rational computational design of next-generation insertion-type materials, such as battery electrode materials, demonstrating how atomistic insights can be systematically translated into continuum-scale predictions.
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https://arxiv.org/abs/2512.24816
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86e22efef37f6fea2a24999b4e1d220954df8f9d473e259755e41fb58f2f5453
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2026-01-01T00:00:00-05:00
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Measuring Mixed-State Topological Invariant in Open Photonic Quantum Walk
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arXiv:2512.24857v1 Announce Type: cross Abstract: Pure-state manifestations of geometric phase are well established and have found applications across essentially all branches of physics, yet their generalization to mixed-state regimes remains largely unexplored experimentally. The Uhlmann geometric phase offers a natural extension of pure-state paradigms and can exhibit a topological character. However, observation of this invariant is impeded by the incompatibility between Uhlmann parallel transport and Hamiltonian dynamics, as well as the difficulty of preparing topologically nontrivial mixed states. To address this challenge, we report an experimentally accessible protocol for directly measuring the mixed-state topological invariant. By engineering controlled nonunitary dynamics in a photonic quantum walk, we prepare topologically nontrivial mixed states from a trivial initial state. Furthermore, by machine-learning the full density matrix in momentum space, we directly extract the quantized geometric phase of the nontrivial mixed states. These results highlight a geometric phase framework that naturally extends to open quantum systems both in and out of thermal equilibrium.
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https://arxiv.org/abs/2512.24857
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fc62604ae249f32dfa278f3774a2542f1021dcaef075e0789acba5e9f2d95b4a
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2026-01-01T00:00:00-05:00
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Metallic solid-state hydrogen storage crystals achieved through chemical precompression under ambient conditions
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arXiv:2512.24876v1 Announce Type: cross Abstract: Improving hydrogen storage density is essential for reducing the extreme conditions required in applications such as nuclear fusion. However, the recognition of metallic hydrogen as the "Holy Grail" of high-pressure science highlights the difficulty of high-density hydrogen aggregation. Here, we report a solid-state crystal H9@C20 formed by embedding hydrogen atoms into C20 fullerene cages and utilizing chemical precompression, which remains stable under ambient pressure and temperature conditions and exhibits metallic properties. This precompression effect is reflected in the formation of C-H bonds within the cage and C-C bonds between cages, resulting in the transformation of all C atoms from sp2 to sp3 hybridization with inward and outward distortions, while promoting delocalized multicenter bonding within the H9 aggregate. In particular, the hydrogen density inside the C20 cage exceeds that of solid hydrogen, achieving a uniform discrete distribution with H9 as monomers. Further study reveals that filling hydrogen molecules into voids between H9@C20 primitive cells can increase hydrogen content while maintaining structural stability, forming a solid-gas mixed hydrogen storage crystal. Our findings provide a basis for developing high-density hydrogen storage materials under ambient conditions.
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https://arxiv.org/abs/2512.24876
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ea90855f16482c755b028d66deb0495b44b314c63b52d37febd2b84e02129938
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2026-01-01T00:00:00-05:00
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Exact Identity Linking Entropy Production and Mutual Information
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arXiv:2512.24877v1 Announce Type: cross Abstract: Linking entropy production (EP) to information is a key step toward data-driven nonequilibrium thermodynamics. We derive an exact identity for overdamped Langevin dynamics that equates the total EP rate to the mutual-information rate between an infinitesimal displacement and its time-symmetric midpoint, up to a bulk mean-flow contribution. This mapping elevates information theory to a thermodynamic calculus: the chain rule yields a canonical, nonnegative split into self and interaction EP, and leads to a tighter bound on learning rate with interaction EP as the necessary cost. As a proof of concept, applying the estimator to red-blood-cell flickering shows that interaction EP robustly exposes active signatures that conventional summaries can miss.
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https://arxiv.org/abs/2512.24877
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fd0fc99e363358ae5c4a354ede1042aec757cf95b0b6605ca418ae9c7c350fee
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2026-01-01T00:00:00-05:00
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Image-Plane Detection of Spatially Entangled Photon Pairs with a CMOS Camera
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arXiv:2512.24878v1 Announce Type: cross Abstract: Spatially entangled photon pairs (biphotons) generated by spontaneous parametric down-conversion offer unique opportunities for quantum imaging, but image-plane biphoton correlations are difficult to observe with camera-based detectors. Previous camera-based biphoton imaging experiments have relied on photon-counting detection, which necessitates operation deep in the photon-sparse regime and requires extremely low dark rates. Here, we demonstrate the detection of spatial biphoton joint probability distributions in both the image plane and the pupil plane (also termed "near-field plane" and "far-field plane" respectively) using a conventional scientific CMOS camera operated in linear mode. We work at mesoscopic intensity levels, corresponding to a photon flux approximately four orders of magnitude higher than typical photon-counting approaches. From the measured image- and pupil plane correlations, we observe position and momentum correlations consistent with an EPR-type entanglement witness. A tailored correlation analysis suited for image plane imaging suppresses detector artifacts and intensity fluctuations, enabling acquisition with significantly fewer frames. Our results demonstrate that spatially entangled-light imaging can be performed efficiently with standard imaging hardware, extending quantum imaging techniques beyond the photon-counting regime.
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https://arxiv.org/abs/2512.24878
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fa59ee6bf607bd805cccc45edce50a64290021545279e22bbd32e6c167d664f0
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2026-01-01T00:00:00-05:00
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Melting curve of correlated iron at Earth's core conditions from machine-learned DFT+DMFT
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arXiv:2512.25061v1 Announce Type: cross Abstract: Reliable constraints on iron's melting curve at Earth's inner-core boundary require accurate finite-temperature electronic correlations, yet DFT+DMFT calculations remain too costly for large-scale thermodynamic sampling. Here, we develop a machine-learning accelerator for charge self-consistent DFT+DMFT by training E(3)-equivariant graph neural networks to predict the local self-energy and Fermi level from atomic environments, providing an efficient warm start to the DMFT self-consistency loop. Using high-throughput data for Fe, FeO, and NiO, we obtain a 2-4 times reuduction in DMFT iterations. Leveraging this improvement, we generate correlated energies and forces for Fe at core pressures, train a neural-network interatomic potential, and determine the melting curve via two-phase coexistence simulations. We obtain a predicted melting temperature of 6225 K at 330 GPa.
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https://arxiv.org/abs/2512.25061
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5a1c09bd4f4ebd32868675680d79a4fd5aef70ecbdb80cc83fc259880a5b7e00
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2026-01-01T00:00:00-05:00
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Positron Bunch Radiation in the System of Tightly Packed Nanotubes
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arXiv:1512.08282v3 Announce Type: replace Abstract: Radiation emitted by a bunch of positrons channeled in nanotubes at zero emission angle is studied taking into account medium polarization. The formation of radiation is characterized by an energy threshold that depends on the oscillation amplitude of each positron. When the bunch energy reaches the maximum value of the threshold energy, radiation is produced by all positrons in the bunch. The nanotube potential barrier is described using a harmonic model. The spectral line shape of the radiation from the positron bunch, the fundamental radiation frequency, and the number of emitted photons are determined. It is shown that a system of tightly packed carbon nanotubes can generate an intense, quasi-monochromatic, and directed beam of circularly polarized soft X-ray photons with an energy of about $3$~\SI{}{\kilo\electronvolt} (wavelength $4.1$~\SI{}{\angstrom}).
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https://arxiv.org/abs/1512.08282
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06611656f1c1759b523d859bfec7a07729226e4eeb3abfed7f1ba2065d38449e
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2026-01-01T00:00:00-05:00
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Excitons: Energetics and spatio-temporal dynamics
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arXiv:2111.06460v2 Announce Type: replace Abstract: The concept of an exciton as a quasiparticle that represents collective excited states was originally adapted from solid-state physics and has been successfully applied to molecular aggregates by relying on the well-established limits of the Wannier exciton and the Frenkel exciton. However, the study of excitons in more complex chemical systems and solid materials over the past two decades has made it clear that simple concepts based on Wannier or Frenkel excitons are not sufficient to describe detailed excitonic behavior, especially in nano-structured solid materials, multichromophoric macromolecules, and complex molecular aggregates. In addition, important effects such as vibronic coupling, the influence of charge-transfer (CT) components, spin-state interconversion, and electronic correlation, which had long been studied but not fully understood, have turned out to play a central role in many systems. This has motivated new experimental approaches and theoretical studies of increasing sophistication. This article provides an overview of works addressing these issues that were published for A Special Topic of the Journal of Chemical Physics on "Excitons: Energetics and spatio-temporal dynamics" and discusses their implications.
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https://arxiv.org/abs/2111.06460
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5e221ee7e346f2cd975b0f71e4eaaf9a0bea64e0db0922ada6951e3178da8805
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2026-01-01T00:00:00-05:00
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Classical Monte Carlo algorithm for simulation of a pseudospin model for cuprates
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arXiv:2301.11708v2 Announce Type: replace Abstract: A classical Monte Carlo algorithm based on the quasi-classical approximation is applied to the pseudospin Hamiltonian of the model cuprate. The model takes into account both local and non-local correlations, Heisenberg spin-exchange interaction, single-particle and correlated two-particle transfer. We define the state selection rule that gives both the uniform distribution of states in the phase space and the doped charge conservation. The simulation results show a qualitative agreement of a phase diagrams with the experimental ones.
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https://arxiv.org/abs/2301.11708
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38e657afe104829bda78d677b601405668b5dd9a8f91b923bd024560e22af382
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2026-01-01T00:00:00-05:00
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Nonadiabatic derivative couplings through multiple Franck-Condon modes dictate the energy gap law for near and short-wave infrared dye molecules
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arXiv:2309.10695v3 Announce Type: replace Abstract: Near infrared (NIR, 700 - 1,000 nm) and short-wave infrared (SWIR, 1,000 - 2,000 nm) dye molecules exhibit significant nonradiative decay rates from the first singlet excited state to the ground state. While these trends can be empirically explained by a simple energy gap law, detailed mechanisms of the nearly universal behavior have remained unsettled for many cases. Theoretical and experimental results for two representative NIR/SWIR dye molecules reported here clarify the key mechanism for the observed energy gap law behavior. It is shown that the first derivative nonadiabatic coupling terms serve as major coupling pathways for nonadiabatic decay processes from the first excited singlet state to the ground state for these NIR and SWIR dye molecules and that vibrational modes other than the highest frequency ones also make significant contributions to the rate. This assessment is corroborated by further theoretical comparison with possible alternative mechanisms of intersystem crossing to triplet states and also by comparison with experimental data for deuterated molecules.
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https://arxiv.org/abs/2309.10695
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eb3e39ff98dac6dc5a2e84bfe1008bab512bc0bcd60df451d61db636a12f0cd9
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2026-01-01T00:00:00-05:00
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Reducibility of higher-order networks from dynamics
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arXiv:2404.08547v4 Announce Type: replace Abstract: Empirical complex systems can be characterized not only by pairwise interactions, but also by higher-order (group) interactions influencing collective phenomena, from metabolic reactions to epidemics. Nevertheless, higher-order networks' apparent superior descriptive power -- compared to classical pairwise networks -- comes with a much increased model complexity and computational cost, challenging their application. Consequently, it is of paramount importance to establish a quantitative method to determine when such a modeling framework is advantageous with respect to pairwise models, and to which extent it provides a valuable description of empirical systems. Here, we propose an information-theoretic framework, accounting for how structure affect diffusion behaviors, quantifying the entropic cost and distinguishability of higher-order interactions to assess their reducibility to lower-order structures while preserving relevant functional information. Empirical analyses indicate that some systems retain essential higher-order structure, whereas in some technological and biological networks it collapses to pairwise interactions. With controlled randomization procedures, we investigate the role of nestedness and degree heterogeneity in this reducibility process. Our findings contribute to ongoing efforts to minimize the dimensionality of models for complex systems.
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https://arxiv.org/abs/2404.08547
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ee60c58a91795b55b0c63e675aa7ceb4fada7f086a715292a4d68e011a0702f3
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2026-01-01T00:00:00-05:00
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Radiation forces and torques in optics and acoustics
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arXiv:2410.23670v3 Announce Type: replace Abstract: The mechanical action of various kinds of waves has been recognized for several centuries. The first tide of scientific interest in wave-induced forces and torques emerged at the turn of the 20th century, with the development of wave theories and the concepts of wave momentum and angular momentum. A second surge occurred in the past several decades, driven by technological breakthroughs: the invention of lasers and the controlled generation of structured wave fields. This resulted in major discoveries, including optical trapping and manipulation of small particles, from atomic to micro sizes, as well as acoustic manipulation of larger particles, including biological cells and samples. Nowadays, radiation forces and torques underpin numerous applications: optical and acoustic tweezers, acoustofluidic sorting of biological cells, optomechanical systems operating in both classical and quantum regimes, solar sails, quantum simulators, volumetric displays, etc. In this review, we present a unifying perspective on optical and acoustic forces and torques acting on various particles, addressing both their theoretical foundations and key applications. Our approach relies on the universal connection between the local energy, momentum, and spin densities of wave fields and the principal forces and torques exerted on small particles. Moreover, we describe important cases of nontrivial (e.g., lateral and pulling) forces and complex (e.g., chiral and anisotropic) particles. We also highlight significant experimental achievements involving optical and acoustic manipulation in structured wave fields. Our aim is to illuminate the common fundamental origins and close interconnections between the mechanical actions of optical and acoustic fields, thereby fostering a deeper understanding and advancing the development of optomechanical and acoustomechanical applications.
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https://arxiv.org/abs/2410.23670
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c1e6a9b668234679af71ab8bd67387e3f2a90771f3cc5390cacf571b19fe2db0
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2026-01-01T00:00:00-05:00
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Quantum Sensing Using Atomic Clocks for Nuclear and Particle Physics
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arXiv:2411.19424v3 Announce Type: replace Abstract: Technologies for manipulating single atoms have advanced drastically in the past decades. Due to their excellent controllability of internal states, atoms serve as one of the ideal platforms as quantum systems. One major research direction in atomic systems is the precise determination of physical quantities using atoms, which is included in the field of precision measurements. One of such precisely measured physical quantities is energy differences between two energy levels in atoms, which is symbolized by the remarkable fractional uncertainty of $10^{-18}$ or lower achieved in the state-of-the-art atomic clocks. Two-level systems in atoms are sensitive to various external fields and can, therefore, function as quantum sensors. The effect of these fields manifests as energy shifts in the two-level system. Traditionally, such shifts are induced by electric or magnetic fields, as recognized even before the advent of precision spectroscopy with lasers. With high-precision measurements, tiny energy shifts caused by hypothetical fields weakly coupled to ordinary matter or by small effects mediated by massive particles can be potentially detectable, which are conventionally dealt with in the field of nuclear and particle physics. In most cases, the atomic systems as quantum sensors have not been sensitive enough to detect such effects. Instead, experiments searching for these interactions have placed constraints on coupling constants, except in a few cases where effects are predicted by the Standard Model of particle physics. Nonetheless, measurements and searches for these effects in atomic systems have led to the emergence of a new field of physics.
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https://arxiv.org/abs/2411.19424
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e79b0193f8980a16aa9facf0ab2ee5cb5562b2c19fec23b74781c62e8993c6c4
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2026-01-01T00:00:00-05:00
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Learning Generalized Diffusions using an Energetic Variational Approach
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arXiv:2412.04480v2 Announce Type: replace Abstract: Extracting governing physical laws from computational or experimental data is crucial across various fields such as fluid dynamics and plasma physics. Many of those physical laws are dissipative due to fluid viscosity or plasma collisions. For such a dissipative physical system, we propose a framework to learn the corresponding laws of the systems based on their energy-dissipation laws, assuming either continuous data (probability density) or discrete data (particles) are available. Our methods offer several key advantages, including their robustness to corrupted/noisy observations, their easy extension to more complex physical systems, and the potential to address higher-dimensional systems. We validate our approaches through representative numerical examples and carefully investigate the impacts of data quantity and data property on model discovery.
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https://arxiv.org/abs/2412.04480
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85eb649212581dc2944bce319ff1d775a0cd9768fe719744074a03f386d3c93e
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2026-01-01T00:00:00-05:00
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A Radio-Frequency Emitter Design for the Low-Frequency Regime in Atomic Experiments
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arXiv:2502.11549v4 Announce Type: replace Abstract: Radio-frequency (RF) control is a key technique in cold atom experiments. We present a compact and efficient RF circuit based on a capacitive transformer network, where a low-frequency coil operating up to 30MHz serves as both an intrinsic inductor and a power-sharing element. The design enables high current delivery and flexible impedance matching across a wide frequency range. We integrate both broadband and narrowband RF networks into a unified configuration that overcomes the geometric constraints imposed by the metallic chamber. In evaporative cooling, the broadband network allows a reduction of the applied RF input power from 14.7dBW to -3.5dBW, owing to its non-zero coil current even at ultra-low frequencies. This feature enables the Bose-Fermi mixture to be cooled below 10{\mu}K. In a Landau-Zener protocol, the coil driven by the narrowband network transfers 80% of rubidium atoms from |F = 2,mF = 2> to |2,-2> in 1 millisecond, achieving a Rabi frequency of approximately 9 kHz at an input power of 0.1dBW.
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https://arxiv.org/abs/2502.11549
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48c0cadfd45ef9b400f323b74f7aace75b06d2efff60101322dc33fc142d5a11
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2026-01-01T00:00:00-05:00
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Bounds on dissipation in three-dimensional planar shear flows: reduction to two-dimensional problems
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arXiv:2503.04005v3 Announce Type: replace Abstract: Bounds on turbulent averages in shear flows can be derived from the Navier--Stokes equations by a mathematical approach called the background method. Bounds that are optimal within this method can be computed at each Reynolds number Re by numerically optimizing subject to a spectral constraint, which requires a quadratic integral to be nonnegative for all possible velocity fields. Past authors have eased computations by enforcing the spectral constraint only for streamwise-invariant (2.5D) velocity fields, assuming this gives the same result as enforcing it for three-dimensional (3D) fields. Here we compute optimal bounds over 2.5D fields and then verify, without doing computations over 3D fields, that the bounds indeed apply to 3D flows. One way is to directly check that an optimizer computed using 2.5D fields satisfies the spectral constraint for all 3D fields. A second way uses a criterion we derive that is based on a theorem of Busse (ARMA 47:28, 1972) for energy stability analysis of models with certain symmetry. The advantage of checking this criterion, as opposed to directly checking the 3D constraint, is lower computational cost and natural extrapolation of the criterion to large Re. We compute optimal upper bounds on friction coefficients for the wall-bounded Kolmogorov flow known as Waleffe flow, and for plane Couette flow. This requires lower bounds on dissipation in the first model and upper bounds in the second. For Waleffe flow, all bounds computed using 2.5D fields satisfy our criterion, so they hold for 3D flows. For Couette flow, where bounds have been previously computed using 2.5D fields by Plasting & Kerswell (JFM 477:363, 2003), our criterion holds only up to moderate Re, so at larger Re we directly verify the 3D spectral constraint. Over the Re range of our computations, this confirms the assumption by Plasting & Kerswell that their bounds hold for 3D flows.
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https://arxiv.org/abs/2503.04005
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79b153f4d9959562de08f57511917d9a99a6f9a43ff4cabc0a4d5a5bc8579c7c
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2026-01-01T00:00:00-05:00
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AttoSHINE: Generation of continuous-wave terawatt-scale attosecond X-ray pulses at SHINE
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arXiv:2506.07213v4 Announce Type: replace Abstract: Attosecond X-ray pulses are a critical tool for tracking ultrafast electron dynamics in condensed matter, molecular systems, and strongly correlated materials. Recent breakthroughs have pushed X-ray free electron lasers (XFELs) into the attosecond domain, significantly surpassing their previous femtosecond capabilities. Building on these advancements, this work investigates the potential of the Shanghai High Repetition Rate XFEL and Extreme Light Facility (SHINE), China's first continuous-wave (CW) XFEL, to generate intense attosecond X-ray pulses, thereby offering transformative capabilities for X-ray science. Through comprehensive start-to-end simulations, we show that SHINE is capable of producing hard X-ray pulses with peak powers reaching the terawatt-scale and average pulse durations of approximately 300 as. This is achieved using a self-chirping scheme within the existing machine configuration, requiring no additional hardware. Our findings demonstrate that CW XFELs can generate intense attosecond X-ray pulses at megahertz repetition rates, opening new opportunities for real-time studies of electronic dynamics in complex systems.
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https://arxiv.org/abs/2506.07213
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1bff969468962ee4394fbb9239018751af3cf5428980380615078ca2c0b83e0b
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2026-01-01T00:00:00-05:00
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Elimination of angular dependency in quantum three-body problem made easy
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arXiv:2506.23962v2 Announce Type: replace Abstract: This work presents a systematic account of elimination of angular dependency from nonrelativistic Schr\"odinger equation for a three-body quantum system with arbitrary masses, charges, angular momentum, and parity. The resulting reduced Schr\"odinger equation (RSE) for the reduced wave components, corresponding to the basis of solid bipolar harmonics, is presented in a compact matrix operator form. The variational form of RSE, providing a practical tool for calculating energy levels and wave functions, is also derived. The resulting angular integrals were derived by expanding bipolar harmonics in a basis of parity-adapted Wigner functions. The theoretical results are numerically validated by computing accurate energy levels for selected states of the helium atom in the explicitly correlated Hylleraas-type basis. The work aims to serve as a self-contained reference for the previously scattered throughout the scientific literature formulation of RSE, offering a convenient foundation for further analytical studies of three-particle quantum systems with arbitrary angular momentum and parity.
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https://arxiv.org/abs/2506.23962
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b58504d5995ca06d2ff76d87b9b2e273201c6c93c7a90a2cb3768d704360ed1b
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2026-01-01T00:00:00-05:00
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An Online Data Analysis Framework for Small-Scale Physics Experiments
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arXiv:2508.00705v3 Announce Type: replace Abstract: A robust and flexible architecture capable of providing real-time analysis on diagnostic data is of crucial importance to physics experiments. In this paper, we present such an online framework, used in June 2025 as part of the HRMT-68 experiment, performed at the HiRadMat facility at CERN, using the Super Proton Synchrotron (SPS) beam line. HRMT-68 was a fixed-target laboratory astrophysics experiment aiming to identify plasma instabilities generated by a relativistic electron-positron beam during traversal of an argon plasma. This framework was essential for experimental data acquisition and analysis, and can be adapted for a broad range of experiments with a variety of experimental diagnostics. The framework's modular and customizable design enabled us to rapidly observe and extract emergent features from a diverse range of diagnostic data. Simultaneously, it allowed for both the introduction of new diagnostic devices and the modification of our analysis as features of interest were identified. As a result, we were able to effectively diagnose equipment malfunction, and infer the beam's response to varying bunch duration, beam intensity, and the plasma state without resorting to offline analysis, at which time adjustment or improvement would have been impossible. We present the features of this agile framework, whose codebase we have made publicly available, which can be adapted for future experiments with minimal modification.
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https://arxiv.org/abs/2508.00705
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b296265eaf25016021bd2dd8119e4bd3ca1026bbb87fc1dc82a918bbb212c990
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2026-01-01T00:00:00-05:00
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Generalized Wigner-Smith theory for perturbations at exceptional and diabolic point degeneracies
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arXiv:2508.05039v2 Announce Type: replace Abstract: Spectral degeneracies, including diabolic (DP) and exceptional (EP) points, exhibit unique sensitivity to external perturbations, enabling powerful control and engineering of wave phenomena. We present a residue-based perturbation theory that quantifies complex resonance splitting of DP and EP type spectral degeneracies using generalized Wigner-Smith operators. We validate our theory using both analytic Hamiltonian models and numerical electromagnetic simulations, demonstrating excellent agreement across a range of cases. Our approach accurately predicts degenerate resonance splitting using only scattering data, offering a powerful framework for precision tuning, inverse design, and practical exploitation of non-Hermitian phenomena.
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https://arxiv.org/abs/2508.05039
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4aca63c4a598f0d271a22f3abb5fb6c310115c3cee3c3040f888598bf81a73c2
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2026-01-01T00:00:00-05:00
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The Effects of a Constructed Closure of the Bering Strait on AMOC Tipping Behavior
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arXiv:2508.19826v2 Announce Type: replace Abstract: The Atlantic Meridional Overturning Circulation (AMOC) is a major tipping element in the present-day climate, and could potentially collapse under sufficient freshwater or CO2-forcing. While the effect of the Bering Strait on AMOC stability has been well studied, it is unknown whether a constructed closure of this Strait can prevent an AMOC collapse under climate change. Here, we show in an Earth system Model of Intermediate Complexity that an artificial closure of the Strait can extend the safe carbon budget of the AMOC, provided that the AMOC is strong enough at the closure time. Specifically, for this model, an equilibrium AMOC with a reduction below (6.1 +/- 0.5)% from pre-industrial has an additional budget up to 500PgC given a sufficiently early closure, while for a weaker AMOC a closure reduces this budget. This indicates that constructing this closure could be a feasible climate intervention strategy to prevent an AMOC collapse.
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https://arxiv.org/abs/2508.19826
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6a15dcde86bad2e7d72ca4f9bf5c1a7f99730d148997a01a1bd5857eb8ad1e9f
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2026-01-01T00:00:00-05:00
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Backward similarity solution of the Boussinesq groundwater equation
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arXiv:2509.07478v2 Announce Type: replace Abstract: Groundwater flow in an unconfined aquifer resting on a horizontal impermeable layer with a boundary condition of a rapid increase in the source water level is considered in this work. The newly introduced condition, referred to as the backward power-law head condition, represents a situation where the water level in the adjacent water body increases more rapidly than do conventional problems, which can only represent a situation akin to a traveling wave under rising water level conditions, given its consideration of infinite time. This problem admits the similarity transformation which allows the nonlinear partial differential equation to be converted into a nonlinear ordinary differential equation via the Boltzmann transformation. The reduced boundary value problem is interpreted as the initial value problem for a system of ordinary differential equations (ODE), which can be numerically solved via Shampine's method. The numerical solutions are in good agreement with Kalashinikov's special solution, which is also introduced into the Boussinesq equation. We find that the solution is consistent with the limit of the forward power-law head condition. The new approximate analytical solution and the associated wetting front position are derived by assuming that the solution has the form of quadratic polynomials, which enables the description of the time progression of a real front position. The obtained approximation is compared to Shampine's solution to check the accuracy. Furthermore, the finite element method is applied to the original partial differential equation (PDE), which validates Shampine's solution for use as a benchmark.
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https://arxiv.org/abs/2509.07478
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e8f34e33e2595995dcc52f1b607bda5d102afe94fc9cb3b0f57ad93daa1a129f
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2026-01-01T00:00:00-05:00
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Programmable Optical Filters Based on Feed-Forward Photonic Meshes
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arXiv:2509.12059v3 Announce Type: replace Abstract: We demonstrate an integrated photonic circuit based on feed forward photonic meshes that can be programmed and reconfigured to perform arbitrary spectral filter functions. We investigate a subset of the available filter functions, demonstrating that a N = 4 input triangular mesh with M = 3 layers may be operated via self-configuration algorithms to filter M arbitrary wavelengths from a given input spectrum. The tunable nature of the architecture enables preconfigured filter functions to be swept in the spectral domain continuously over the free spectral range of the device. This removes any strict requirements between the design parameters of the architecture and the center wavelength of a desired filter function. With this architecture, we experimentally demonstrate arbitrary wavelength rejection filters with contrasts as deep as 40 dB. Further, by intentionally selecting the center wavelengths of each filter function to lie along a wavelength grid we demonstrate deep wavelength division demultiplexing (DWDM) with inter-channel crosstalk between -25 dB and -40 dB. Unlike typical DWDM systems, in this architecture the center wavelength of each channel is not fixed at fabrication and instead may be swept or reordered arbitrarily. This device demonstrates advantages over typical methods for DWDM, Raman spectroscopy, and correlation spectroscopy as well as other applications.
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https://arxiv.org/abs/2509.12059
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47433acb545e2ef88c4a5182336d051be7a2d30cb3b07ac106273c372ff515f7
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2026-01-01T00:00:00-05:00
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Time-diffracting 2D wave vortices
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arXiv:2510.10147v2 Announce Type: replace Abstract: Wave vortices constitute a large family of wave entities, closely related to phase singularities and orbital angular momentum (OAM). So far, two main classes of localized wave vortices have been explored: (i) transversely-localized monochromatic vortex beams that carry well-defined longitudinal OAM and propagate/diffract along the longitudinal $z$-axis in space, and (ii) 2D-localized spatiotemporal vortex pulses that carry the more elusive transverse (or tilted) OAM and propagate/diffract along both the $z$-axis and time. Here we introduce another class of wave vortices which are localized in a 2D $(x,y)$ plane, do not propagate in space (apart from uniform radial deformations), and instead propagate/diffract solely along time. These vortices possess well-defined transverse OAM and can naturally appear in 2D wave systems, such as surface polaritons or water waves. We provide a general integral expression for time-diffracting 2D wave vortices, their underlying ray model, and examples of approximate and exact wave solutions. We also analyze the temporal Gouy phase closely related to the rotational evolution in such vortices. Finally, we show that time-diffracting 2D vortices can provide strong spatiotemporal concentration of energy and OAM at sub-wavelength and oscillation-period scales.
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https://arxiv.org/abs/2510.10147
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56c2d1926a73313f2ff74e5cec66c38b6ccbf1d37b072f9af7c9d8ab9c31645c
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2026-01-01T00:00:00-05:00
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Dependence of Microstructure Classification Accuracy on Crystallographic Data Representation
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arXiv:2510.13104v2 Announce Type: replace Abstract: Convolutional neural networks are increasingly being used to analyze and classify material microstructures, motivated by the possibility that they will be able to identify relevant microstructural features more efficiently and impartially than human experts. While up to now convolutional neural networks have mostly been applied to light optimal microscopy and scanning electron microscope micrographs, application to EBSD micrographs will be increasingly common as rational design generates materials with unknown textures and phase compositions. This raises the question of how crystallographic orientation should be represented in such a convolutional neural network, and whether this choice has a significant effect on the network's analysis and classification accuracy. Four representations of orientation information are examined and are used with convolutional neural networks to classify five synthetic microstructures with varying textures and grain geometries. Of these, a spectral embedding of crystallographic orientations in a space that respects the crystallographic symmetries performs by far the best, even when the network is trained on small volumes of data such as could be accessible by practical experiments.
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https://arxiv.org/abs/2510.13104
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10b405b69d19ba83606d4357f61d102c5092318adcdf1e05bfface67cf48d2e5
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2026-01-01T00:00:00-05:00
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Long-lived giant circular Rydberg atoms at room temperature
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arXiv:2510.27471v2 Announce Type: replace Abstract: Stability achieved by large angular momentum is ubiquitous in nature, with examples ranging from classical mechanics, over optics and chemistry, to nuclear physics. In atoms, angular momentum can protect excited electronic orbitals from decay due to selection rules. This manifests spectacularly in highly excited Rydberg states. Low angular momentum Rydberg states are at the heart of recent breakthroughs in quantum computing, simulation and sensing with neutral atoms. For these applications the lifetime of the Rydberg levels sets fundamental limits for gate fidelities, coherence times, or spectroscopic precision. The quest for longer Rydberg state lifetimes has motivated the generation, coherent control and trapping of circular Rydberg atoms, which are characterized by the maximally allowed electron orbital momentum and were key to Nobel prize-winning experiments with single atoms and photons. Here, we report the observation of individually trapped circular Rydberg atoms with lifetimes of more than 10 milliseconds, two orders of magnitude longer-lived than the established low angular momentum orbitals. This is achieved via Purcell suppression of blackbody modes at room temperature. We coherently control individual circular Rydberg levels at so far elusive principal quantum numbers of up to $n=103$, and observe tweezer trapping of the Rydberg atoms on the few hundred millisecond scale. Our results pave the way for quantum information processing and sensing utilizing the combination of extreme lifetimes and giant Rydberg blockade.
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https://arxiv.org/abs/2510.27471
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990289fd1d056bfb5d22c0dc9f08f2e24aba7e267589c019873b1cb3f81e939b
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2026-01-01T00:00:00-05:00
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Enhanced cooperativity of J-exciton-polaritons in dielectric BIC metasurfaces
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arXiv:2511.08103v2 Announce Type: replace Abstract: Highly correlated photon sources can be realized through cooperative coupling among quantum systems, giving rise to superradiant collective emission. In solid-state ensembles, however, such collective behaviour is confined to subwavelength dimensions and is strongly suppressed at room temperature by inhomogeneous broadening and rapid dephasing, limiting practical implementations. Here, we show that molecular J-aggregates sustain room temperature superradiant emission and enter a highly collective regime when strongly coupled to delocalized photonic modes of a silicon bound-state-in-the-continuum (BIC) metasurface, extending J-exciton interactions far beyond the subwavelength limit. This enhanced cooperativity produces a Rabi-splitting-dependent increase in emission rate and intensity and drives the system into a highly superbunched photon emission regime with g(2)(0)>13. Stochastic modelling reveals that metasurface-mediated synchronization of ~10^3 J-excitons occurs within coupled superradiant domains spanning up to 8.5 um in diameter, corresponding to a 50-fold increase in inter-aggregate cooperative distance. These results establish common-mode coupling in resonant dielectric metasurfaces as a scalable route for engineering ultrafast, temporally correlated light sources operating at room temperature.
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https://arxiv.org/abs/2511.08103
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de74c5b5db2d4c3e066797f8d252debde7fb70c7a0643f4f8057956ed8d3d481
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2026-01-01T00:00:00-05:00
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Electric-Field-Induced Tautomerism in Metal-Free Benziporphyrins Enables Aromaticity-Controlled Conductance Switching
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arXiv:2511.21727v2 Announce Type: replace Abstract: Metal-free porphyrins can switch between hydrogen-bonded tautomers, potentially enabling reversible control in molecular electronics. However, electric field gating of porphyrin tautomerism, which is critical for device integration, has not been fully realized. We propose metal-free benziporphyrins (MFBPs), in which one pyrrole ring is replaced with a phenol group, as a new platform for tautomer-based molecular electronics. This approach introduces asymmetry, which allows for three distinct tautomers, each possessing a characteristic aromatic or antiaromatic electronic structure. Density functional theory and quantum transport calculations show that: i) experimentally realisable electric fields can selectively stabilize each tautomer, and ii) each tautomer exhibits a characteristic conductance profile. The strong switching capability of MFBPs is demonstrated by ON/OFF ratios exceeding 500 at low bias. Fused MFBPs further expand functionality by providing multiple tautomeric states for multistate molecular registers and enabling wire-like architectures with enhanced conductance. These results establish MFBPs as versatile building blocks for electric-field-responsive molecular devices and open new research opportunities for molecular-scale logic and memory.
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https://arxiv.org/abs/2511.21727
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86244846f101e8242d1eb1324afe5e6bfdd5882d6fa7ecfe170a0374d8e1c81f
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2026-01-01T00:00:00-05:00
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Optical Response in Spintronic Poisson Bolometers
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arXiv:2512.14968v2 Announce Type: replace Abstract: Analog bolometers based on temperature-dependent phase-transition materials such as vanadium oxide (VOx) and barium titanate (BTO) represent the state of the art in uncooled infrared detectors. Recently, the first room-temperature spintronic Poisson bolometer based on magnetic tunnel junctions (MTJs) was proposed and demonstrated as a promising infrared detector. Unlike conventional bolometers, the spintronic Poisson bolometer operates in a probabilistic regime dominated by Poissonian noise, where the response is governed by resistance fluctuations arising from thermally activated magnetization transitions. Spontaneous transitions between two metastable magnetic states occur even in the absence of incident light, and the transition probability increases under illumination. In this work, we experimentally study the statistical properties of the optical response of the spintronic Poisson bolometer under illumination. We demonstrate that transitions in spintronic Poisson bolometers, both in the absence and presence of light, exhibit Poissonian behavior, with transition rates and interarrival times modulated by incident radiation. Under illumination, we observe a 153% increase in the count rate accompanied by a 70% reduction in interarrival time. These results establish spintronic Poisson bolometers as a promising platform for probabilistic, high-speed, and high-sensitivity infrared detection at room temperature.
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https://arxiv.org/abs/2512.14968
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d45da5c78a3fc62e640c50930942677797cd017c34dea5fa9a98873e4997007b
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2026-01-01T00:00:00-05:00
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Magneto-optical Skyrmion for manipulation of arbitrary light polarization
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arXiv:2512.21006v2 Announce Type: replace Abstract: Dynamic manipulation of arbitrary light polarization is of fundamental importance for versatile optical functionalities, yet realizing such full-Poincar\'e-sphere control within compact nanophotonic architectures remains a formidable challenge. Here, we theoretically propose and numerically demonstrate a magneto-optical skyrmion platform enabling full polarization control of cavity eigenmodes. We reveal the correspondence between the near-field wavefunctions of degenerate dipoles and far-field polarization. By applying multidirectional magnetic fields to magneto-optical photonic crystals, we achieve any complex superposition of orthogonal eigenmodes, thereby realizing arbitrary far-field polarization. This mapping manifests as a skyrmion with a topological charge of 2, guaranteeing coverage of the entire Poincar\'e sphere. Our theoretical model shows excellent agreement with full-wave simulations. Furthermore, we realize bound states in the continuum (BICs) with dynamically tunable polarization textures and demonstrate high-performance polarization-selective emission and transmission. This work establishes a topological paradigm for precise polarization shaping, offering new avenues for advanced optical communication and sensing.
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https://arxiv.org/abs/2512.21006
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619a3300aa33675dc258b75c5ac9919407e34a30949aad6d1bf80fa6e4591a2f
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2026-01-01T00:00:00-05:00
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Electrode Geometry Optimization in Vortex-Type Seawater Magnetohydrodynamic Generators
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arXiv:2512.22446v2 Announce Type: replace Abstract: Magnetohydrodynamics (MHD) generators present a promising pathway for clean energy conversion by directly transforming conductive fluids' kinetic energy into electricity. This study investigates the impact of electrode geometry modifications on the performance of a vortex-type seawater MHD generator. Three electrode designs, partial, whole-area, and spiral, are analyzed through combined analytical and numerical simulations using COMSOL Multiphysics. The study focuses on internal resistance reduction, current density distribution, and overall power output. The results indicate that electrode area and spacing are critical determinants of performance. The whole-area electrode achieves the highest output, with a 155 percent increase in power compared to the baseline partial electrode. The spiral electrode demonstrates reduced internal resistance and improved current flow but exhibits lower open-circuit voltage due to reduced electrode spacing. The simulations show strong agreement with theoretical models, with deviations of less than 4 percent in open-circuit voltage predictions. These findings highlight the importance of geometric optimization for advancing seawater-based MHD generators as sustainable and efficient energy conversion systems.
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https://arxiv.org/abs/2512.22446
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0d7a9dc7b3f2b9ed7cece052902c81282da2c8742316f7a6c9b990cdfe008df3
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2026-01-01T00:00:00-05:00
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Theoretical calculations of isotope shifts in highly charged Ni$^{12+}$ ion
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arXiv:2512.22850v2 Announce Type: replace Abstract: We present relativistic many-body perturbation theory plus configuration interaction (MBPT+CI) calculations of the lowest four excited states of Ni$^{12+}$, a promising candidate for highly charged ion (HCI) optical clocks. By combining the convergence behavior from multiple calculation models, we perform a detailed analysis of the electron-correlation effects and both the excitation energies and their uncertainties are obtained. Our computed energies for the first two excited states deviate from experimental values by less than $10~\mathrm{cm^{-1}}$, with relative uncertainties estimated below $0.2\%$. Building on the same computational procedure, we calculate the mass shift and field shift constants for the lowest four excited states of Ni$^{12+}$, and the resulting isotope shifts exhibit valence-correlation-induced relative uncertainties below the $1\%$ level. These results provide essential atomic-structure input for high-precision isotope shift spectroscopy in Ni$^{12+}$.
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https://arxiv.org/abs/2512.22850
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adf99ee3ca02ce95e59e72af783dcbf63f60a80d6cc3f1dd869bb0c6d698747c
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2026-01-01T00:00:00-05:00
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Thermodynamically Consistent Vibrational-Electron Heating: Generalized Model for Multi-Quantum Transitions
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arXiv:2512.23072v2 Announce Type: replace Abstract: Accurate prediction of electron temperature ($T_{\rm e}$) is critical for non-equilibrium plasma applications ranging from hypersonic flight to plasma-assisted combustion. We recently proposed a thermodynamically consistent model for vibrational-electron heating [Phys. Fluids 37, 096141 (2025)] that enforces the convergence of $T_{\rm e}$ to the vibrational temperature ($T_{\rm v}$) at equilibrium. However, the original derivation was restricted to single-quantum transitions, limiting its validity to low-temperature regimes ($T_{\rm e} \lesssim 1.5$ eV). In this Letter, we generalize the model to include multi-quantum overtone transitions, extending its applicability to high-energy regimes. We demonstrate that previous models neglecting hot-band transitions incur a systematic heating error of $\exp(-\theta_{\rm v}/T_{\rm v})$, where $\theta_{\rm v}$ is the characteristic vibrational temperature. This error exceeds 40\% when $T_{\rm v}$ is greater than $\theta_{\rm v}$, effectively preventing thermal relaxation. To correct this, we derive a formulation where the total heating rate is a summation of channel-specific cooling rates $Q_{\rm e-v}^{(m)}$, each associated with a quantum jump $m$, scaled by a thermodynamic factor $\exp(m\theta_{\rm v}/T_{\rm e}-m\theta_{\rm v}/T_{\rm v})$. This generalized model preserves thermodynamic consistency by ensuring zero net energy transfer at equilibrium.
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https://arxiv.org/abs/2512.23072
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1ea8bbb4fd2f001ea83bfec9c8d436e6a2e9d40f6a7569cc55d81491bea66d40
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2026-01-01T00:00:00-05:00
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A simple generalization of the energy gap law for nonradiative processes
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arXiv:2110.09464v2 Announce Type: replace-cross Abstract: For more than 50 years, an elegant energy gap (EG) law developed by Englman and Jortner [Mol. Phys. {\bf 18}, 145 (1970)] has served as a key theory to understand and model nearly exponential dependence of nonradiative transition rates on the difference of energy between the initial and final states. This work revisits the theory, clarifies key assumptions involved in the rate expression, and provides a generalization for the cases where the effects of temperature dependence and low frequency modes cannot be ignored. For a specific example where the low frequency vibrational and/or solvation responses can be modeled as an Ohmic spectral density, a simple generalization of the EG law is provided. Test calculations demonstrate that this generalized EG law brings significant improvement over the original EG law. Both the original and generalized EG laws are also compared with stationary phase approximations developed for electron transfer theory, which suggests the possibility of a simple interpolation formula valid for any value of EG.
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https://arxiv.org/abs/2110.09464
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Academic Papers
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c0892c819254e0eaec3639f1f91d6fd2ae49b382a2667324cda5fde952dd7f0e
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2026-01-01T00:00:00-05:00
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Partially polaron-transformed quantum master equation for exciton and charge transport dynamics
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arXiv:2203.02812v3 Announce Type: replace-cross Abstract: Polaron-transformed quantum master equation (PQME) offers a unified framework to describe the dynamics of quantum systems in both limits of weak and strong couplings to environmental degrees of freedom. Thus, PQME serves as an efficient method to describe charge and exciton transfer/transport dynamics for a broad range of parameters in condensed or complex environments. However, in some cases, the polaron transformation (PT) being employed in the formulation invokes an over-relaxation of slow modes and results in premature suppression of important coherence terms. A formal framework to address this issue is developed in the present work by employing a partial PT that has smaller weights for low frequency bath modes. It is shown here that a closed form expression of a 2nd order time-local PQME including all the inhomogeneous terms can be derived for a general form of partial PT, although more complicated than that for the full PT. All the expressions needed for numerical calculation are derived in detail. Applications to a model of two-level system coupled to a bath of harmonic oscillators, with test calculations focused on those due to homogeneous relaxation terms, demonstrate the feasibility and the utility of the present approach.
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https://arxiv.org/abs/2203.02812
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Academic Papers
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57dd672c0ac7b1bf892929e7ed4ddc082e602def6adaff6490d6b6595e948238
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2026-01-01T00:00:00-05:00
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Simple and general unitarity conserving numerical real time propagators of time dependent Schr\"odinger equation based on Magnus expansion
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arXiv:2312.01115v2 Announce Type: replace-cross Abstract: Magnus expansion (ME) provides a general way to expand the real-time propagator of a time-dependent Hamiltonian within the exponential such that the unitarity is satisfied at any order. We use this property and explicit integration of Lagrange interpolation formulas for the time-dependent Hamiltonian within each time interval and derive approximations that preserve unitarity for the differential time evolution operators of general time-dependent Hamiltonians. The resulting second-order approximation is the same as using the average of Hamiltonians for two end points of time. We identify three fourth-order approximations involving commutators of Hamiltonians at different times and also derive a sixth-order expression. A test of these approximations along with other available expressions for a two-state time-dependent Hamiltonian with sinusoidal time dependences provides information on the relative performance of these approximations and suggests that the derived expressions can serve as useful numerical tools for time evolution in time-resolved spectroscopy, quantum control, quantum sensing, real-time ab initio quantum dynamics, and open system quantum dynamics.
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https://arxiv.org/abs/2312.01115
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Academic Papers
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345e8aea4c9e6211f0c3ee4438d21b71d057f728fcd91c2168be5ee01817ee2c
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2026-01-01T00:00:00-05:00
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Fermi's golden rule rate expression for transitions due to nonadiabatic derivative couplings in the adiabatic basis
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arXiv:2405.02697v3 Announce Type: replace-cross Abstract: Starting from a general molecular Hamiltonian expressed in the basis of adiabatic electronic and nuclear position states, where a compact and complete expression for nonadiabatic derivative coupling (NDC) Hamiltonian term is obtained, we provide a general analysis of the Fermi's golden rule (FGR) rate expression for nonadiabatic transitions between adiabatic states. We then consider a quasi-adiabatic approximation that uses crude adiabatic states evaluated at the minimum potential energy configuration of the initial adiabatic state as the basis for the zeroth order adiabatic and NDC coupling terms of the Hamiltonian. Although application of this approximation is rather limited, it allows deriving a general FGR rate expression without further approximation and still accounts for non-Condon effect arising from momentum operators of NDC terms and its coupling with vibronic displacements. For a generic and widely used model where all nuclear degrees of freedom and environmental effects are represented as linearly coupled harmonic oscillators, we derive a closed form FGR rate expression that requires only Fourier transform. The resulting rate expression includes quadratic contributions of NDC terms and their couplings to Franck-Condon modes, which require evaluation of two additional bath spectral densities in addition to conventional one that appears in a typical FGR rate theory based on the Condon approximation. Model calculations for the case where nuclear vibrations consist of both a sharp high frequency mode and an Ohmic bath spectral density illustrate new features and implications of the rate expression. We then apply our theoretical expression to the nonradiative decay from the first excited singlet state of azulene, which illustrates the utility and implications of our theoretical results.
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https://arxiv.org/abs/2405.02697
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Academic Papers
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90f366de242707ec1dc029ed4c1bf0e3fc44c8575035b0ce105fccf4883564ad
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2026-01-01T00:00:00-05:00
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Investigation of resistive switching in Au/MoS2/Au using Reactive Molecular Dynamics and ab-initio quantum transport calculations
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arXiv:2407.11437v2 Announce Type: replace-cross Abstract: In this work, we investigate the underlying physical mechanism for electric-field induced resistive switching in Au/MoS2/Au based memristive devices by combining reactive Molecular Dynamics (MD) and ab-initio quantum transport calculations. Using MD with Au/Mo/S ReaxFF potential, we observe the formation of realistic conductive filament consisting of gold atoms through monolayer MoS2 layer when sufficient electric field is applied. We furthermore instigate the rupture of the gold atom filament when a sufficiently large electric field is applied in the opposite direction. To calculate the conductance of the obtained structures and identify the High Resistance (HR) and Low Resistance (LR) states, we employ the ab-initio electron transport calculations by importing the atomic structures from MD calculations. For single-defect MoS2 memristors, the obtained LRS, HRS current densities are in order of 10^7 A/cm^2 which agrees reasonably well with the reported experiments.
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https://arxiv.org/abs/2407.11437
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Academic Papers
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0c25e2977262ea12b8f902fed0216d6d3d3f0b00eb718fda57c2a83f26a7bfa8
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2026-01-01T00:00:00-05:00
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Eigenstate thermalization to non-monotonic distributions in strongly-interacting chaotic lattice gases
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arXiv:2501.08967v4 Announce Type: replace-cross Abstract: We find non-monotonic equilibrium energy distributions, qualitatively different from the Fermi-Dirac and Bose-Einstein forms, in strongly-interacting many-body chaotic systems. The effect emerges in systems with finite energy spectra, supporting both positive and negative temperatures, in the regime of quantum ergodicity. The results are supported by exact diagonalization calculations for chaotic Fermi-Hubbard and Bose-Hubbard models, when they have Wigner-Dyson statistics of energy spectra and demonstrate eigenstate thermalization. The proposed effects may be observed in experiments with cold atoms in optical lattices.
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https://arxiv.org/abs/2501.08967
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Academic Papers
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482665c7a46476ef382c73a08045696aade67f0d3ceae797d8838404faa4fb67
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2026-01-01T00:00:00-05:00
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Hierarchical Loop Stabilization in Periodically Driven Elastic Networks
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arXiv:2503.19681v2 Announce Type: replace-cross Abstract: Network remodeling, or adaptation, in the presence of periodically driven forcings has hereto remained largely unexplored, despite the fact that a broad class of biological transport networks, e.g. animal vasculature, depends on periodic driving (pulsatility of the heart) to maintain flow. Short-term pulsatile dynamics of compliant vessels affects the long-term structures of adapting networks; however, what the correct adaptation rule is for pulsatile flows still remains an open question. Here we propose a new adaptation rule for periodically driven complex elastic networks that accounts for the effect of short-term pulsatile dynamics on the remodeling signal at long time-scales. Using this rule to adapt hierarchical elastic networks with multiple levels of looping, we show that very different network architectures are possible at steady-state depending on the driving frequency of the pulsatile source and the geometric asymmetry of the paths between the externally driven nodes of the network. Specifically resonant frequencies are shown to prioritize the stabilization of fully looped structures or higher level loops proximal to the source, whereas anti-resonant frequencies predominantly stabilize loop-less structures or lower-level loops distal to the source. Thus, this model offers a mechanism that can explain the stabilization of phenotypically diverse loopy network architectures in response to source pulsatility under physiologically relevant conditions and in the absence of other known loop stabilization mechanisms, such as random fluctuations in the load or perfusion homogenization.
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https://arxiv.org/abs/2503.19681
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Academic Papers
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d764ce8222c1e5b968148eddb8ac56677d653b7bc20141884fa13d8eee8956bc
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2026-01-01T00:00:00-05:00
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An electron-hadron collider at the high-luminosity LHC
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arXiv:2503.20475v3 Announce Type: replace-cross Abstract: We discuss a concept of a lower-energy version of the Large Hadron-electron Collider (LHeC), delivering electron-hadron collisions concurrently to the hadron-hadron collisions at the high-luminosity LHC at CERN. Assuming the use of a 20 GeV electron Energy Recovery Linac (ERL), we report the results on the optimised beam dynamics, accelerator technologies, and detector constraints required for such a "phase-one" LHeC. Finally, we also discuss the ERL configurations and the possibility of delivering electron-hadron collisions during the planned {Run5} of the LHC, which opens excellent research capabilities - the unique scientific potential of the proposed facility is outlined.
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https://arxiv.org/abs/2503.20475
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Academic Papers
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f32a8758a98a90fb175182f791bbb94a7191d355b8e52153617c35af6dbecfc3
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2026-01-01T00:00:00-05:00
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Interplay of Coil-Globule Transitions and Aggregation in Homopolymer Aqueous Solutions: Simulation and Topological Insights
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arXiv:2504.19147v2 Announce Type: replace-cross Abstract: We investigate the structural and topological properties of hydrophobic homopolymer chains in aqueous solutions using molecular dynamics simulations and circuit topology (CT) analysis. By combining geometric observables, such as radius of gyration and degree of aggregation, with CT data, we capture the relationship between coil-globule and aggregation transitions, resolving the system's structural changes with temperature. Our results reveal a temperature-driven collective transition from isolated coiled chains to globular aggregates. At a characteristic transition temperature $T_c$, each chain in multichain systems undergoes a rapid coil-globule collapse, coinciding with aggregation, in contrast to the gradual collapse observed in single-chain systems at infinite dilution. This collective transition is reflected in geometric descriptors and a reorganization of CT motifs, shifting from intrachain-dominated motifs at low temperatures to a diverse ensemble of multichain motifs at higher temperatures. CT motif enumeration provides contact statistics while offering a topologically detailed view of polymer organization. These findings highlight CT's utility as a structural descriptor for polymer systems and suggest applications to biopolymer aggregation and folding.
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https://arxiv.org/abs/2504.19147
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Academic Papers
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32d3e09a685ee4251ec0cfa42c601d96cbf1a60a7b0879dcbab7f647b81f759c
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2026-01-01T00:00:00-05:00
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Deep-learning atomistic semi-empirical pseudopotential model for nanomaterials
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arXiv:2505.09846v2 Announce Type: replace-cross Abstract: The semi-empirical pseudopotential method (SEPM) has been widely applied to provide computational insights into the electronic structure, photophysics, and charge carrier dynamics of nanoscale materials. We present "DeepPseudopot", a machine-learned atomistic pseudopotential model that extends the SEPM framework by combining a flexible neural network representation of the local pseudopotential with parameterized non-local and spin-orbit coupling terms. Trained on bulk quasiparticle band structures and deformation potentials from GW calculations, the model captures many-body and relativistic effects with very high accuracy across diverse semiconducting materials, as illustrated for silicon and group III-V semiconductors. DeepPseudopot's accuracy, efficiency, and transferability make it well-suited for data-driven in silico design and discovery of novel optoelectronic nanomaterials.
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https://arxiv.org/abs/2505.09846
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Academic Papers
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501f01bd5a2021809fc3e805d7b189daf57d3fb02e2d1e421a9527b965c3340d
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2026-01-01T00:00:00-05:00
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Local-available quantum correlation swapping in one-parameter X states
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arXiv:2507.23142v2 Announce Type: replace-cross Abstract: Although introduced for entanglement, quantum repeaters and swapping protocols have been analyzed for other quantum correlations (QC), such as quantum discord. In 2015, Mundarain and Ladr\'on de Guevara [Quantum Inf. Process. 14, 4493 (2015)] introduced local-available quantum correlations (LAQC), which are a promising yet understudied quantum correlation. Recently, Bellorin et al. [Int. J. Mod. Phys. B 36, 22500990 (2022), Int. J. Mod. Phys. B 36, 2250154 (2022)] obtained exact analytical results for the LAQC quantifier of general 2-qubit X states. Building up from those results, we analyzed the LAQC swapping for 2-qubit X states. As expected, we find that if the initial states are non-classical and the one used for the projective measurement is entangled, the final state will generally have non-zero LAQC. Using the properties of this quantum correlation, we establish the conditions for a QCS scheme that leads to a final state with a non-zero LAQC measure. We illustrate these results by analyzing five families of one-parameter 2-qubit X states, including families where the projective measure leads to a separable state, but whose LAQC measure is non-zero. This feature opens the possibility for this quantum correlation to be considered a genuine resource in quantum information technology.
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https://arxiv.org/abs/2507.23142
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Academic Papers
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16267690e5e4b8efb6b1b1b36dd3f8e4e1a73a2748a0d1408fe0b2c2a7581953
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2026-01-01T00:00:00-05:00
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Multivalent linkers mediated ultra-sensitive bio-detection
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arXiv:2508.00346v3 Announce Type: replace-cross Abstract: In biosensing and diagnostic applications, a key objective is to design detection systems capable of identifying targets at very low concentrations, i.e., achieving high sensitivity. Here, we propose a linker-mediated detection scheme in which the presence of multivalent target molecules (linkers) facilitates the adsorption of ligand-coated guest nanoparticles onto a receptor-coated host substrate. Through a combination of computer simulations and mean-field theory, we demonstrate that, at fixed overall binding strength, increasing the valency of linkers exponentially lowers the concentration threshold for detection. This counterintuitive behavior arises from the combinatorial entropy associated with multivalent binding configurations, which tremendously amplifies the adsorption sensitivity and enables the identification of targets at extremely low concentrations. Our findings highlight multivalency engineering of linkers as a powerful strategy to substantially enhance the sensitivity of biodetection systems.
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https://arxiv.org/abs/2508.00346
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Academic Papers
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