Plasma Physics · Cross-listed from cond-mat.mes-hall
The role of the exchange-Coulomb potential in two-dimensional electron transport
J. L. Figueiredo, J. T. Mendonça and H. Terças
We develop a
quantum kinetic theory of two-dimensional electron gases in which exchange is treated self-consistently at the Hartree-Fock level and enters as a nonlocal, momentum-dependent field in phase space. By starting from the Coulomb
Hamiltonian, we derive a Hartree-Fock-Wigner equation for the electronic Wigner function and obtain a closed fluid model with exchange-corrected pressure, force, and current. For a single layer, we show that exchange renormalizes the
Fermi velocity and can drive a long-wavelength plasmonic instability at low densities. In coupled layers, the same framework predicts acoustic-optical mode coupling, and an instability forming long-lived charge-imbalance patterns that are not predicted by classical Vlasov and Boltzmann models. Finally, we apply the kinetic model to the Coulomb drag problem and show how exchange substantially enhances the drag resistivity in dilute GaAs double wells, quantitatively matching experimental observations.
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Applied Physics · Cross-listed from quant-ph
Solving the inverse parametric problem
Michele Cortinovis, Fabio Lingua and David B. Haviland
We present a method to calculate the frequency components of a pump waveform driving a parametric oscillator, which realizes a desired frequency mixing or scattering between modes. The method is validated by numerical analysis and we study its sensitivity to added Gaussian noise. A series of experiments apply the method and demonstrate its ability to realize complex scattering processes involving many modes at microwave frequencies, including non-reciprocal mode circulation. We also present an approximate method to dynamically control mode scattering, capable of rapidly routing signals between modes in a prescribed manner. These methods are useful tools for encoding and manipulating continuous variable
quantum information with multi-modal Gaussian states.
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Optics
Towards coherent polaritonic circuits operating at room temperature
Addhyaya Sharma, Ezra Bader, Ravindra K. Yadav et al. (+6 more)
Polariton condensation is a potential system state for performing analog computations, given that it exhibits
quantum behavior at macroscopic scales readily probed with low-cost optical methods. Current methods of fabricating devices in polariton microcavities largely involve patterning the devices via e-beam lithography before the cavity is completed, which offers less flexibility in device creation and reduces the maximum possible refractive index contrast. Moreover, the momentum and spatial distributions of the condensate are highly dependent on the host platform, and it has been difficult to preserve the desired behavior when modifying a given cavity. Here we introduce a method that addresses both of these challenges with the creation of polaritonic
circuits of arbitrary forms etched via Focused Ion Beam into an organic microcavity based on Rhodamine 3B Perchlorate within a Small Molecule Ionic Isolation
Lattices complex. We demonstrate room temperature condensation and propagation of polaritons in rectangular and trapezoidal waveguides by analyzing spatial and angle-resolved photoluminescence. We also discuss the blue-shifting and non-zero momentum of the condensate and show that it is strongly confined up to several higher energy levels. As an example, we report the spatial profiles of condensation in custom devices, such as a ring waveguide, a Y-splitter, and a Mach-Zehnder interferometer. This work represents a first step towards the realization of more complex, fully integrated, coherent polaritonic
circuits operating at room temperature.
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All authors Addhyaya Sharma, Ezra Bader, Ravindra K. Yadav, Juan Carlos Obeso Jureidini, Michael Reitz, Daegwang Choi, Rishabh Kaurav, Joel Yuen-Zhou, Vinod M. Menon
Instrumentation and Detectors
A muon scattering tomography system based on high spatial resolution scintillating detector
Zheng Liang, Zebo Tang, Xin Li et al. (+8 more)
Cosmic ray
muon scattering
tomography (MST) is an imaging technique that utilizes
muon scattering in matter to inspect high-Z materials non-destructively, without requiring an artificial radiation source. This method offers significant potential for applications in border security and long-term monitoring of
nuclear materials. In this study, we developed a high-precision plastic-scintillator-based position-sensitive detector with a spatial resolution of 0.09 times the strip pitch. A fully functional, full-scale imaging system was then constructed using four layers of such XY position-sensitive detectors, each with an effective area of 53 cm x 53 cm. This paper details the following key contributions: the Geant4-simulated design and optimization of the imaging system, the fabrication, assembly, and testing of the detectors, and an evaluation of the imaging performance of the completed system.
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All authors Zheng Liang, Zebo Tang, Xin Li, Baiyu Liu, Cheng Li, Jiacheng He, Kun Jiang, Yonggang Wang, Ye Tian, Yishuang Zhang, Zeyu Wang
Chemical Physics · Cross-listed from cond-mat.mtrl-sci
Lithium-ion battery degradation: Introducing the concept of reservoirs to design for lifetime
Mohammed Asheruddin Nazeeruddin, Ruihe Li, Simon E. J. OKane et al. (+2 more)
Designing lithium-ion batteries for long service life remains a challenge, as most
cells are optimized for beginning-of-life metrics such as energy density, often overlooking how design and operating conditions shape degradation. This work introduces a degradation-aware design framework built around finite, interacting reservoirs (lithium, porosity, and electrolyte) that are depleted over time by coupled degradation processes. We extend a physics-based Doyle-Fuller-Newman model to include validated mechanisms such as SEI growth, lithium plating, cracking, and solvent dry-out, and simulate how small design changes impact lifetime. Across more than 1,000 cycles, we find that increasing electrolyte volume by just 1% or porosity by 5% can extend service life by over 30% without significantly affecting
cell energy density. However, lithium excess, while boosting initial capacity, can accelerate failure if not supported by sufficient structural or ionic buffers. Importantly, we show that interaction between reservoirs is crucial to optimal design: multi-reservoir tuning yields either synergistic benefits or compound failures, depending on operating conditions. We also quantify how C-rate and operating temperature influence degradation pathways, emphasizing the need for co-optimized design and usage profiles. By reframing degradation as a problem of managing finite internal reservoirs, this work offers a predictive and mechanistic foundation for designing lithium-ion batteries that balance energy, durability, and application-specific needs.
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All authors Mohammed Asheruddin Nazeeruddin, Ruihe Li, Simon E. J. OKane, Monica Marinescu, Gregory J. Offer
Fluid Dynamics
On bifurcations and traction forces on an obstacle in incompressible flow
Jakub Cach, Karel Tůma, Jan Blechta et al. (+1 more)
A systematic numerical investigation of flow-regime transitions in the two-dimensional incompressible Navier-Stokes flow past a confined circular cylinder is presented. For a fixed
benchmark geometry, we observe a clear empirical correspondence between qualitative changes in steady traction profiles, understood here as the pointwise force density given by the Cauchy stress tensor on the obstacle boundary, and bifurcations in the long-time behavior of the unsteady Navier-Stokes equations. The observed transitions include onset of time-periodic oscillations, the appearance of multiple steady solutions and loss of effective
symmetry. The well-known planar Schäfer-Turek
benchmark is considered for Reynolds numbers up to 500. Several numerical techniques are employed to compute steady solutions, boundary traction profiles, and linear stability spectra such as duality-based approach for traction evaluation, deflation methods for detecting multiple steady states, and both two- and three- dimensional linear stability analyzes. The results suggest that steady boundary traction profiles can serve as a sensitive diagnostic indicator of critical Reynolds numbers at which qualitative changes in flow dynamics occur. This suggests a computationally inexpensive, complementary approach for detecting flow-regime transitions within this
benchmark configuration.
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All authors Jakub Cach, Karel Tůma, Jan Blechta, Sebastian Schwarzacher
Fluid Dynamics
Spatio-temporal analysis of sprays by using Phase Doppler Anemometry data
Erika Rácza, Milan Malý, Jan Jedelský et al. (+1 more)
Spray characterization often relies on empirical formulas, statistical distributions, and derived quantities. Deterministic spray behavior originates from physics-governed mechanisms of atomization, e.g., nozzle geometry, boundary conditions, and hydrodynamic instabilities. Due to the
stochastic nature of the atomization process, which originates from
turbulence, chaotic perturbations, and droplet–droplet interactions, the temporal characteristics of dynamic behavior are seldom investigated. The combination of these processes leads to droplet clustering, which is a spatio-temporal behavior that is the focus of the current paper for an airblast atomizer. The measurement data by Phase Doppler Anemometry include droplet size, velocity, and arrival time. Firstly, the theoretical and experimental interparticle time distributions are compared using a $\chi^2$ hypothesis test, which concluded multimodality. Secondly, k-means clustering is applied to determine droplet clusters, whose number was determined by gap statistics. The above analysis was performed using an extensive database of various measurement positions, atomizing pressures,
liquid preheating temperatures, and
liquid types. It was found that cluster formation affects approximately 30% of the droplets in a single data set. In conclusion, the unsteadiness in the central region is caused by clustering, while it is caused by mixing and droplet entrainment in the spray periphery. The centroids and the number of cluster values depend on the atomizing pressure and the spray position, and are independent of the
liquid temperature. The dynamical behavior of the clusters is compared by their droplet size and velocity distributions, showing no significant difference, suggesting that unsteady spray modeling is necessary if temporal characteristics are critical.
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All authors Erika Rácza, Milan Malý, Jan Jedelský, Viktor Józsa
Computational Physics
UGKS and UGKWP Methods for Multiscale Simulation of Electrostatic Plasma in Quasineutral and Hydrodynamic Limits
Zhigang Pu and Kun Xu
This study extends the Unified Gas-Kinetic Scheme (UGKS) and the Unified Gas-Kinetic Wave-Particle (UGKWP) method for electrostatic
plasma modeling, ensuring the correct asymptotic limits with respect to both the Debye length and the mean free path. By coupling collision and transport processes within the numerical flux, the proposed approach effectively removes the hydrodynamic-limit constraint associated with the mean free path. In addition, a reformulated Poisson equation, coupled with the macroscopic moment equations, is introduced to overcome the inefficiency of the standard Poisson formulation in the quasineutral regime. The accuracy and asymptotic consistency of the proposed schemes are verified through several
benchmark tests, including linear and nonlinear Landau damping and the bump-on-tail instability. The results demonstrate that the methods robustly capture
plasma dynamics across hydrodynamic and quasineutral regimes, without resolution constraints imposed by either the Debye length or the mean free path.
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Physics and Society
Network localization governs social contagion dynamics with macro-level reinforcement
Leyang Xue, Kai-Cheng Yang, Peng-Bi Cui et al. (+1 more)
The spread of ideas, behaviors, and technologies generally depends on feedback mechanisms operating across multiple scales. Previous studies have extensively examined pairwise transmission and local reinforcement. However, the role of macro-level social influence – where widespread adoption enhances further adoption – remains understudied. Here, we focus on a contagion process that incorporates both pairwise interactions and macro-level reinforcement. We show that the contagion undergoes a shift from continuous to mixed-order transition as macro-level influence exceeds a reinforcement threshold. Simulations on various real-world networks indicate that network localization governs the contagion outcomes by determining the critical point and the reinforcement threshold. Building on this insight, we develop a structural metric linking network localization to contagion dynamics, revealing a key trade-off: networks that facilitate weak contagion tend to experience slower
diffusion and lower adoption rates, while networks that suppress weak contagions enable faster and more widespread adoption. These findings challenge the conventional belief that stronger local connectivity uniformly promotes contagion.
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All authors Leyang Xue, Kai-Cheng Yang, Peng-Bi Cui, Zengru Di
Optics
Orientation-dependent high harmonic generation in ZnO
Tzveta Apostolova, Balint Kiss, Deborata Rajak et al. (+6 more)
We theoretically and experimentally investigate orientation-dependent high-harmonic generation (HHG) in zinc
oxide subjected to intense femtosecond mid-infrared (MIR)
laser pulses. In agreement with past measurements from literature, we observe non-perturbative harmonic spectra with harmonics extending beyond the material band gap. The spectra depend sensitively on the orientation of the
crystal with respect to the
laser polarization direction. To
benchmark the measurements, we performed detailed theoretical calculation of the orientation-dependent harmonic yields. The theory predicts a three-fold angular modulation of the intensity of odd-order harmonics in the (0001)-plane, which can be deduced from the
symmetry of the hexagonal
lattice alone, in contrast a four-fold
symmetry is observed in the experiment. The theory points out the essential role of the anisotropy of the multiple band structure affecting the dynamics of electron-hole pair excitation and solid-state HHG.
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All authors Tzveta Apostolova, Balint Kiss, Deborata Rajak, Katalin Pirisi, Rajaram Shrestha, Levente Abrok, Boyan Obreshkov, Jean Claude Kieffer, Dimitar Velkov
Plasma Physics
First implementation of AXUV-based analysis and macro-instability diagnostics on WHAM
K. Shih, D. Endrizzi, D.A. Sutherland et al. (+13 more)
Absolute extreme ultraviolet (AXUV) diode arrays are widely used in fusion experiments for time-resolved measurements of
plasma radiation. We report the first implementation of an AXUV-based analysis framework on the Wisconsin High-Temperature Superconducting (HTS) Axisymmetric Mirror (WHAM). A single, precisely calibrated 20-channel AXUV assembly measures line-integrated
plasma emission with $ 100~\mathrm{kHz}$ temporal resolution and $\sim1~\mathrm{cm}$ spatial accuracy across the mid-plane. The data were processed to obtain
plasma's statistical moments, yielding time-resolved measurement of the centroid displacement $\Phi(t)$ and effective radius $R(t)$. From the joint covariance of these quantities, we define a macroscopic instability parameter $\chi(t)$, that quantifies large-scale
plasma motion and profile
evolution directly from AXUV observables. The parameter $\chi$ serves as a compact indicator of global macroscopic instability, decreasing with increasing end-plate bias and exhibiting strong anti-correlation with diamagnetic flux during confinement transitions. These results demonstrate that a single AXUV array can provide quantitative, real-time assessment of macroscopic
plasma instabilities, constituting the first demonstration of such capability in a
magnetic mirror
plasma. Future extensions to multiple arrays will further enhance spatial coverage and enable full-mode tracking in axisymmetric mirror configurations and related fusion devices.
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All authors K. Shih, D. Endrizzi, D.A. Sutherland, J. Anderson, D. Bindl, E.L. Claveau, C. Everson, J. Eickman, S.J. Frank, E. Marriott, E. Penne, J. Pizzo, T. Qian, J. Viola, C.B. Forest, D. Yakovlev
Physics and Society
Energy and GHG saving potentials of sufficiency measures – a synthesis for Germany
Carina Zell-Ziegler, Célia Burghardt, Kaya Dünzen et al. (+5 more)
The sixth assessment report of the Intergovernmental Panel on
Climate Change (IPCC) emphasises the potential of demand-side measures, such as sufficiency, for mitigating
climate change. Although quantified potentials of various sufficiency measures exist, policy advisors and energy modellers criticise the lack of findability and comparability of the relevant data. Due to the high level of heterogeneity in units, reference points and calculation methods, the data cannot be used to summarise sufficiency potentials at a national level. Consequently, this paper aims to identify, structure, harmonise and synthesise existing data in order to determine the greatest saving potentials per sector and highlight data gaps. Based on a systematic literature review, we have created a curated open-source database containing over 300 quantified energy and greenhouse gas (GHG) saving potentials for Germany, which could be used as a blueprint for other such data collections. Most quantifications were available for the building sector, particularly for appliances. The highest total energy and GHG emission savings in Germany were identified in measures that reduce per capita living space, with saving potentials of -150 Terawatt-hours per year (TWh/a) and -118 Million Tons of Carbon Dioxide Equivalents per year (Mt CO2eq./a; this measure also includes lower heating temperatures). This synthesis can help modellers to better account for sufficiency potentials in scenarios, and help policymakers to understand the saving potentials of sufficiency. We encourage researchers to quantify more energy and GHG saving potentials in order to fill the identified gaps and to use the proposed synthesis structure.
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All authors Carina Zell-Ziegler, Célia Burghardt, Kaya Dünzen, David Schöpf, Jenny Kurwan, Benjamin Best, Mirko Schäfer, Frauke Wiese
Fluid Dynamics
The study of coherent Rayleigh-Brillouin scattering in multiple flow regimes using unified gas-kinetic scheme
Xiaozhe Xi, Junzhe Cao and Kun Xu
Coherent Rayleigh-Brillouin scattering (CRBS) holds great promise for the characterization of gas properties and the investigation of gas kinetic processes. The CRBS spectrum exhibits a strong dependence on the Knudsen number (Kn), revealing its inherently multiscale nature. In the unified gas-kinetic scheme (UGKS), collisions are intrinsically coupled with free transport during flux construction, endowing the method with distinct multiscale capabilities. Specifically, the UGKS reduces to a Boltzmann solver when the relaxation time is greater than or equal to the time step, and to the gas-kinetic scheme (GKS)-a Navier-Stokes solver-when the relaxation time is much smaller than the time step, thereby accommodating flow regimes without constraints on the molecular mean free path or collision time. In this study, the UGKS is extended to simulate CRBS phenomena, with the governing equation formulated based on the BGK-Shakhov model. Detailed derivations are provided. To account for the additional perturbation source term, a second-order accurate numerical
algorithm is developed using the Strang splitting method within the UGKS framework. The proposed model is validated against argon CRBS experiments, demonstrating excellent agreement. Building on this validated framework, the impact of incident signal intensity on CRBS spectra across a range of Knudsen numbers is systematically examined, accompanied by an in-depth analysis of the underlying physical mechanisms. This work broadens the applicability of CFD-based CRBS simulations and provides a reliable numerical foundation for exploring high-intensity, multiscale gas-kinetic phenomena in future research.
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Chemical Physics · Cross-listed from cond-mat.soft
Extended defects in hard disk system and melting criteria
M.V. Kondrin, Y.B. Lebed and V.V. Brazhkin
The hard sphere model is widely used in description of fluids and solid media as a zero approximation to real systems. Despite the uniqueness of the model, few analytical results are known for it, both for the 2D and 3D cases. In present research we have investigated melting of the hard disk system by considering accumulation of extended defects of a certain type in the crystaline phase, and jamming of the disk packing. It results in formulation of melting criteria with lower and upper bounds on volume ratio at melting transition: $25/21 \le V/V_0 \le 5/4$. It was found that, in full agreement with the Berezinskii-Kosterlitz-Thouless-Halperin-Nelson-Young theory, the 2D
crystal melts into anisotropic
liquid. The second transition, which is the transition between anisotropic and isotropic
liquid has volume ratio $5/4 \le V/V_0 \le 13/9$.
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Biological Physics
Reconstruction of the Bacterial Flagellar Motor's Energy Landscape, Viscous Load, and Torque Generation Across Diffusion Regimes
N. J. Lopez-Alamilla, A. L. Nord, F. Pedaci et al. (+2 more)
The bacterial flagellar motor (BFM) converts transmembrane ion flux into directed mechanical rotation, driving bacterial motility. Despite extensive study, the frictional forces and energetics governing its torque generation remain poorly understood. Here, we combine single-molecule rotation measurements with
stochastic thermodynamics to quantitatively estimate its effective torque, viscous drag and activation energy barriers. We present three complementary methods based on solutions to the Smoluchowski equation for overdamped
diffusion in a tilted periodic potential, which use as input the steady-state angular velocity and rotational
diffusion data from individual E. coli motors spanning different dynamical regimes. Crucially, these three methods require neither active external torque control, nor prior knowledge of the system's viscous drag or the motor's torque output. The first method assumes as input a model-dependent sinusoidal potential (single
Fourier mode), albeit with unknown periodicity, yielding closed-form results in the low- and high-tilt limits, whereas the last two methods use a full
Fourier-based reconstruction to output the now model-independent potential landscape. These approaches yield consistent estimates of the potential periodicity ($\approx$ 26-fold
symmetry), energy barrier height ($\approx 2\!-\!4 k_{\rm B}T$), and internal friction coefficient ($\approx 0.1$ pN nm s rad$^{-2}$). Our results reveal that the BFM's torque-velocity relationship deviates significantly from the linear approximation near the critical tilt, where angular
diffusion is maximized. More broadly, our framework provides a coherent strategy for reconstructing nanoscale energy landscapes from single-molecule data and is generalizable to other stepping molecular motors operating in cyclic conditions.
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All authors N. J. Lopez-Alamilla, A. L. Nord, F. Pedaci, J. Palmeri, N.-O. Walliser
Optics
Integrated on-chip quantum light sources on a van der Waals platform
Pietro Metuh, Paweł Wyborski, Athanasios Paralikis et al. (+4 more)
Scalable photonic
quantum information technologies require a platform combining
quantum light sources, waveguides, and detectors on a single chip. Here, we introduce a van der Waals platform comprising strain-engineered
bilayer WSe$_2$
quantum emitters, integrated on multimode WS$_2$ waveguides with grating couplers, enabling efficient on-chip
quantum light sources. The emitters exhibit bright, highly polarised emission that couples efficiently into WS$_2$ waveguides. Under discrete-state excitation, we observe high-purity, waveguide-coupled single-
photon emission, measured using both single-port and cross-correlated, multi-port
photon streams, yielding $g^{(2)}(0) = 0.003^{+0.030}_{-0.003}$ and $g^{(2)}(0) = 0.076\pm0.023$, respectively. For a single output, the out-coupled single-
photon count rate at the first lens reaches approximately 357 kHz under continuous-wave discrete-state excitation, corresponding to an estimated minimum waveguide-coupled rate of 1.68 MHz. These results demonstrate an efficient, integrated single-
photon source and establish a pathway toward scalable photonic
quantum information processing centred around nanoengineered van der Waals materials.
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All authors Pietro Metuh, Paweł Wyborski, Athanasios Paralikis, Frederik Schröder, Nicolas Stenger, Niels Gregersen, Battulga Munkhbat
Instrumentation and Detectors
Pixel response characterization of the ARCADIA Fully Depleted MAPS
C. Pantouvakis, M. Rignanese, T. Zenger et al. (+24 more)
Monolithic Active Pixel Sensors (MAPS) achieved widespread use in several scientific applications, thanks to their properties, such as low material budget and high granularity. The ARCADIA INFN project developed a Fully-Depleted MAPS (FD-MAPS), using a modified LFoundry 110 nm CIS process. This work presents the first laboratory characterization of the ARCADIA MD3 prototype. Measurements include threshold uniformity studies using both test-pulse injection and a $^{55}$Fe source, as well as threshold and noise calibration achieved thanks to monochromatic X-ray sources. Ultimately, charge-collection efficiency is evaluated using an infrared
laser setup.
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All authors C. Pantouvakis, M. Rignanese, T. Zenger, S. Ciarlantini, A. Zingaretti, P. Azzi, C. Bonini, D. Chiappara, S. Mattiazzo, D. Pantano, J. Wyss, A. Apresyan, N. Bacchetta, L. Bolla, A. Hayrapetyan, C. Pena, N. Salvador, S. Xie, I. Zoi, D. Falchieri, S. Garbolino, L. Pancheri, A. Paternò, A. Rivetti, M. Rolo, R. Santoro, P. Giubilato
Atomic Physics
Bound-electron self-energy calculations in Feynman and Coulomb gauges: detailed analysis
M. A. Reiter, E. O. Lazarev, D. A. Glazov et al. (+2 more)
The energy correction associated with the self-energy diagram is the leading (in magnitude) and fundamental (in significance) contribution to the Lamb shift in highly charged ions. Conventional approaches to this correction rely on partial-wave expansions, which is a stumbling block limiting accuracy. To elucidate the issue, we perform a comprehensive comparative analysis of partial-wave-expansion convergence between two gauges: Feynman and Coulomb. Some tricks for improving the convergence are discussed as well.
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All authors M. A. Reiter, E. O. Lazarev, D. A. Glazov, A. V. Malyshev, A. V. Volotka
Biological Physics
Is the Goldman-Hodgkin-Katz equation universally true?
Yoav Green
No. Eighty years ago, the two seminal works by Goldman [J. Gen. Phys. 27, 37 (1943)] and by Hodgkin-Katz [J. of Physio 108, 37 (1949)] derived the foundational framework for interpreting electro-physiological measurements in what is commonly termed the Goldman-Hodgkin-Katz (GHK) theory for the membrane potential. Both seminal papers postulate a constant/uniform electric field within the ion channel. Using a uniform electric field allows for a simple, straightforward calculation of the ionic fluxes and the transmembrane potential, which yields the famous GHK potential. The use of this framework is so widely accepted that one can find a plethora of works that no longer cite the original works and GHK has perhaps become the universal and indisputable descriptor of the underlying physics and biology. In recent works [Phys. Rev. Lett. 134, 228401 (2025) and Phys. Rev. E 111, 064408 (2025)], we revisited GHK and its assumption of a uniform field. Non-approximated numerical simulations showed that the electric field is not always uniform. To understand this discrepancy, it is important to understand that the governing equations can be solved using two different approaches: the GHK approach of assuming a constant electric field or postulating that the system is electroneutral. Each approach yields drastically different non-commutative results. The purpose of this report is to provide a non-mathematical summary of the results and to inform the broader community that GHK is not as universal as previously thought. We will discuss these two newer works, with some emphasis on how they can potentially revolutionize the interpretation of electro-physiological measurements. Importantly, we show that this new framework, which utilizes the mathematical tools developed by the electrodialysis community, also serves as a bridge linking the electrophysiology community and the electrodialysis community.
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Plasma Physics
MHD Simulation Study on Impurity Assimilation Efficiency and Disruption Dynamics during Shattered Pellet Injection
Jinqiang Mao, Ping Zhu and Shiyong Zeng
Shattered Pellet Injection (SPI) has become a critical technique for mitigating
plasma disruptions in fusion devices, yet optimizing its efficiency demands a proper understanding of the interaction between
impurity dynamics and MHD response. We perform 3D nonlinear MHD simulations of SPI-induced disruption in a J-TEXT-like tokamak using the NIMROD code, systematically examining key parameters: fragment velocity and fineness, injection quantity,
impurity composition, injection location and multiple injectors, resistivity, and parallel thermal conductivity. We find that slower fragment velocity enhances
impurity assimilation and amplifies MHD activity. Finer fragments significantly increase
impurity ablation and cooling efficiency. Mixed deuterium-neon pellets effectively elevate electron density without compromising radiative cooling efficiency.
Plasma poloidal rotation affects ablation and cooling efficiency, whereas toroidally uniform multi-pellet injection enhances
impurity ablation by nearly a factor equal to the number of pellets and lowers radiation asymmetry. Higher
plasma parallel thermal conductivity results in higher radiation cooling efficiency in parallel directions, enhances
impurity transport, and reduces toroidal peaking factor (TPF) of radiation. Variations in resistivity significantly influence Ohmic heating,
impurity deposition and current dynamics after TQ, with higher resistivity leading to stronger
magnetic perturbations and more pronounced current spikes. These findings provide physical bases for optimizing SPI schemes in future tokamak devices.
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Instrumentation and Detectors
Calibration Methods of Silicon Photomultiplier for JUNO-TAO Central Detector
Jiayang Xu, Yichen Li, Zhan Liang et al. (+2 more)
The Taishan Antineutrino Observatory (TAO or JUNO-TAO) is a satellite observatory for the Jiangmen Underground
Neutrino Observatory (JUNO), located 44 meters away from the No.1 reactor of the Taishan
Nuclear Power Plant. TAO can measure the reactor antineutrino energy spectrum with excellent energy resolution (better than 2% at 1 MeV) using state-of-the-art Silicon Photomultipliers (SiPMs) operated at low temperature. To achieve this goal, the SiPMs (together with their readout electronics) must be well calibrated. This paper presents the channel-level calibration methods for the dark count rate (DCR), relative
photon detection efficiency (PDE), time offset, gain, and internal optical crosstalk (IOCT) of the SiPMs based on charge and time information of the collected events. For the tile-level calibration of the external optical crosstalk (EOCT), in terms of its rate and emission angle distribution, a novel method is proposed by switching on and off different groups of SiPMs with an LED placed in the detector. Using one million simulated events, the expected calibration biases are evaluated for all the aforementioned parameters: relative PDE (~3%), IOCT (1.4%), DCR (0.4%), EOCT Rate (<0.1%), gain (<0.1%), time offset (<0.2 ns). The emission angle distribution of the EOCT
photons could be measured with a bias of less than 4% in the main angular range. With the this calibration accuracy, the overall impacts of SiPM parameter uncertainties and calibration biases on vertex precision and energy resolution are limited, with relative degradation below 2% and 3%, respectively. It verifies the validity of the calibration method for the JUNO-TAO detector.
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All authors Jiayang Xu, Yichen Li, Zhan Liang, Guofu Cao, Zelin Chen
Chemical Physics
Ab initio insights into plasmonic and strong-field contributions to H$_2$ dissociation on silver nanoshells
Natalia E. Koval, J. Iñaki Juaristi and Maite Alducin
Modeling plasmonic catalysis by applying femtosecond
laser pulses of high intensity ($10^{13}-10^{15}$ W cm$^{-2}$), although justified by the time-dependent density functional theory (TDDFT) time-scale limitations, can lead to a dissociation mechanism that is completely unrelated to the plasmon excitation created under low-intensity continuous light in experiments (on the order of 1 W cm$^{-2}$). In this study, we examine the dissociation of H$_2$ on a large octahedral Ag nanoshell under varying field intensity, frequency, and duration, and we explore the possibility of identifying optimal modeling conditions accessible with current TDDFT simulations. We show that using this large nanoshell that consists in the outer layer of the Ag$_{231}$ cluster, it is still possible to disentangle the role of the plasmon from strong-field effects at applied field intensities as high as $(2-8) \times 10^{13}$ W cm$^{-2}$. In particular, although strong-field effects are always present at these intensities, we find that the excited plasmon dominates the dissociation process at the lowest applied intensity of $2 \times 10^{13}$ W cm$^{-2}$. Furthermore, at the highest intensity, at which strong-field effects become dominant, the plasmon contributes to accelerating the dissociation of the molecule. Overall, our simulations pave the way to bridge the intensity gap between TDDFT modeling and experiments in plasmonic catalysis.
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Plasma Physics · Cross-listed from astro-ph.HE
Magnetised turbulent plasmas as high-energy particle accelerators
M. Lemoine
This proceedings paper reports on the theoretical modelling of particle acceleration in magnetised turbulent
plasmas. It briefly reviews some recent findings obtained from fully kinetic numerical simulations of large-amplitude, semi to fully relativistic
turbulence. The paper then argues that these findings can be understood within the framework of a “generalised
Fermi” picture of
stochastic acceleration, which it summarises. The dominant contributions to acceleration appear to arise from particle interactions with sharp, dynamic bends of the
magnetic field lines and regions of velocity compression. Interestingly, the acceleration rate is spatially inhomogeneous and its probability distribution follows a broken power law extending up to large values. This makes relativistic, large-amplitude
turbulence an extreme particle accelerator. Some implications for particle transport and the shape of the particle energy spectrum in the presence of radiative losses and over long timescales are also discussed.
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Biological Physics
Modeling Plant Action Potentials under Photoperiod Stress via Hodgkin-Huxley Dynamics
Imen Bekkari, Maurizio Magarini and Hamdan Awan
Plants exhibit dynamic bioelectric properties that facilitate information transfer across tissues. This study investigates action potentials (APs) in Nicotiana tabacum recorded within a custom-designed growth chamber using a biosignal amplifier and environmental sensors. Consistent light- and dark-induced APs were observed during photoperiod transitions under controlled 12-hour artificial illumination cycles. To understand these bioelectric responses, a mathematical model based on the Hodgkin-Huxley framework is used. Electrophysiological measurements from Solanum lycopersicum revealed that under natural light conditions, only light-induced APs are observed, while light- and dark-induced APs coupled dynamics is exclusively elicited during rapid transitions in artificial photoperiods. These distinct phenomena are characterized as Prolonged Oscillatory Climatic Engagement (POCE) and Nimble Environmental Transition Oscillation (NETO), respectively. The model successfully reproduces the key features in both frameworks while maintaining computational efficiency through voltage-independent rate parameters.
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Data Analysis and Statistics · Cross-listed from hep-ex
ColliderML: The First Release of an OpenDataDetector High-Luminosity Physics Benchmark Dataset
Doğa Elitez, Paul Gessinger, Daniel Murnane et al. (+5 more)
We introduce ColliderML - a large, open, experiment-agnostic
dataset of fully simulated and digitised
proton-
proton collisions in High-Luminosity Large
Hadron Collider conditions ($\sqrt{s}=14$ TeV, mean pile-up $\mu = 200$). ColliderML provides one million events across ten Standard Model and Beyond Standard Model processes, plus extensive single-particle samples, all produced with modern next-to-leading order
matrix element calculation and showering, realistic per-event pile-up overlay, a validated OpenDataDetector geometry, and standard reconstructions. The release fills a major gap for machine learning (ML) research on detector-level data, provided on the ML-friendly Hugging Face platform. We present physics coverage and the generation, simulation, digitisation and reconstruction pipeline, describe format and access, and initial
collider physics
benchmarks.
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All authors Doğa Elitez, Paul Gessinger, Daniel Murnane, Marcus Selchou Raaholt, Andreas Salzburger, Stine Kofoed Skov, Andreas Stefl, Anna Zaborowska
Atmospheric and Oceanic Physics
Huayu: Advanced Real-Time Precipitation Estimation from Geostationary Satellite
Zijiang Song, Ting Liu, Lina Yuan et al. (+6 more)
As
climate change drives increased frequency and intensity of extreme precipitation and flooding worldwide, posing escalating threats to public safety and economic assets, accurate and real-time satellite-based precipitation estimation is essential for operational large-scale hydrometeorological analysis and disaster monitoring. NASA's Integrated Multi-satellitE
Retrievals for GPM (IMERG Final Run) combines information from "all" satellite microwave observations with gauge correction and climatological adjustment to produce precipitation estimates at 0.1{\deg} spatial and 30-min temporal resolution. However, its latency of approximately 3.5 months restricts its utility for real-time applications, despite outperforming mainstream satellite precipitation
datasets in representing rainfall patterns and variability. We present Huayu, a novel machine learning-based real-time satellite precipitation
retrieval system that relies solely on infrared observations from the FengYun-4B geostationary satellite to provide a more accurate precipitation estimate at a finer spatiotemporal resolution (15 min, 0.05{\deg}) over a 120{\deg} by 120{\deg} domain. Performance evaluations demonstrate that Huayu achieves strong consistency with rain gauge observations, yielding a critical success index (CSI) of 0.693 - representing a 3.43% improvement over IMERG Final Run (CSI: 0.670). Experimental results confirm that infrared satellite observations can deliver more accurate precipitation estimates than conventional multi-source
algorithms.
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All authors Zijiang Song, Ting Liu, Lina Yuan, Yuying Li, Ao Xu, Xigang Sun, Ye Li, Feng Lu, Min Liu
Biological Physics
Quantum Dynamics of a Nanorotor Driven by a Magnetic Field
V. N. Binhi
A molecular rotor mechanism is proposed to explain weak
magnetic field effects in biology. Despite being nanoscale (1 nm), this rotor exhibits
quantum superposition and interference. Analytical modeling shows its
quantum dynamics are highly sensitive to weak, but not strong,
magnetic fields. Due to its enhanced moment of inertia, the rotor maintains
quantum coherence relatively long, even in a noisy cellular environment. Operating at the mesoscopic boundary between
quantum and classical behavior, such a rotor embedded in cyclical biological processes could exert significant and observable biological influence.
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Fluid Dynamics
Forcing regimes in the two-dimensional Navier-Stokes equations
Ritwik Mukherjee, John D. Gibbon and Dario Vincenzi
In the standard theoretical setting of body-forced
turbulence, the forcing that sustains the flow is concentrated in a narrow range of length scales. However, in experiments of fractal-grid
turbulence and in numerical simulations inspired by the renormalization group approach, more general forcing functions have been considered. These studies have shown that the phenomenology of
turbulence is sensitive to the regularity of the forcing, which raises the wider question of the sensitivity of all Navier–Stokes mathematical estimates to the regularity of body forces. To answer this question, it is necessary to convert the traditional estimates based on the Grashof number, a dimensionless measure of the magnitude of the forcing, to a form dependent on the Reynolds number, the usual dimensionless number in experimental measurements and statistical theories of
turbulence. To investigate these issues we consider the two-dimensional case and employ the full range of forcing regularity allowed by the theory of weak solutions to extend available estimates not only for the energy and enstrophy dissipation rates, but also for the dimension of the global attractor. What emerges is the existence of three distinct regimes as a function of the regularity of the forcing.
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Plasma Physics · Cross-listed from astro-ph.EP
Characterising injection signatures in Jupiter's ultraviolet aurora using Juno observations
Linus Head, Denis Grodent, Bertrand Bonfond et al. (+12 more)
Discrete features in Jupiter's ultraviolet aurora have been interpreted as signatures of
plasma injections in the middle magnetosphere. There exists some ambiguity whether magnetodisc scattering or high-latitude Alfvenic acceleration best describes the observed properties of these injection signatures, and also to what extent arcs in the outer emission are related to injections. Many injection signatures are the result of the
evolution of dawn storms; there is, however, limited evidence that non-dawn-storm injection signatures are sometimes present in the aurora. We use automatic detection of these discrete features, alongside data from Juno-UVS and in-situ measurements by other Juno instruments, to show that scattering likely accounts for most of the electron precipitation associated with injection signatures. Additionally, there is evidence that injection signatures can be classified into two types: dawn-storm and non-dawn-storm. Arc-like features in the outer emission show very similar properties to traditional blob-like injection signatures and may consist of sequences of injection signatures that have broadened into an arc via energy-dependent electron drift.
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All authors Linus Head, Denis Grodent, Bertrand Bonfond, Alessandro Moirano, Guillaume Sicorello, Julie Vinesse, Alyssa Mouton, Maïté Dumont, Thomas Greathouse, Vincent Hue, Ali Sulaiman, Barry Mauk, Zhonghua Yao, Ruilong Guo, Jinyan Zhao
Plasma Physics · Cross-listed from astro-ph.SR
Discussion on the vanishment of solar atmospheric structures during magnetic reconnection
Jun Zhang, Tao Ding and Yulei Wang
In
solar atmosphere,
magnetic reconnection alters the topological connectivity, and
magnetic energy is released. However, the length change of the reconnecting structures has rarely been reported. To identify the
evolution of the topological structures, we search for reconnection events which should satisfy 3 criteria. (1) Each event displays an explicit X-type configuration, and the configuration consists of two sets of independent atmospheric structures, (2) the reconnection process is clearly observed, and (3) the topological connectivity of the structures can be tracked from at least 5 minutes prior to the occurrence of
magnetic reconnection to 5 minutes after the reconnection. In this work, 3 events are selected and studied. During the reconnection moment, the total length of the two topological structures in each event shortens suddenly, and the decrements for events 1–3 are 47 Mm, 3.7 Mm, and 8.2 Mm, respectively, implying that partial structures vanish observationally during
magnetic reconnection process. Several possibilities about the vanishment, e.g. the shrinkage of the reconnecting structures due to
magnetic tension, the bizarre change in the third dimension, and
magnetic field annihilation, have been discussed.
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