Quantum Physics
Deterministic Universal Logical Gates for Finite-Energy GKP Qubits in Trapped Neutral Atoms
Alok Kumar, Aaron N. Raja, Diksha Thapliyal et al. (+2 more)
We present a universal logical gate set for finite-energy Gottesman-Kitaev-Preskill (GKP)
qubits encoded in the harmonic motional states of trapped neutral atoms. Internal electronic states serve as ancilla for implementing state-dependent conditional displacements in phase space, enabling arbitrary single-
qubit phase gates. A Transient Rydberg excitation-mediated atomic dipole-dipole interaction enables a controlled-Z gate without invoking the blockade mechanism. The gates operate under magic-trapping conditions, allowing continuous trapping throughout the gate sequence, thereby preserving the motional encoding without intermediate measurement or feedforward. We assess the experimental feasibility of the proposed protocols using neutral $^{88}\mathrm{Sr}$ atoms and obtain average gate fidelities of $0.986$ for single-
qubit phase gates and $0.985$ for the controlled-Z gate at a finite squeezing parameter of $\Delta=0.25$ (12 dB of squeezing), increasing to $0.997$ and $0.995$ respectively as $\Delta$ reaches $0.1$. These results provide a route toward universal, measurement-free logical control of motional GKP
qubits in neutral-atom architectures.
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All authors Alok Kumar, Aaron N. Raja, Diksha Thapliyal, Ishitwa Kumar Das, Ajay Wasan1
Statistical Mechanics
Effective Hardcore Exclusion Without Exclusion: Two-Species Pair Annihilation Revisited
Su-Chan Park and Foster Thompson
Reaction-
diffusion systems with two species that mutually annihilate through $A+B\to\emptyset$ reactions display a slow decay of the total density $\rho$ which follows an anomalous power law in low dimensions. For hardcore particles in one dimension, this decay follows $\rho \sim t^{-1/4}$ under symmetric
diffusion and $\rho \sim t^{-1/3}$ under asymmetric
diffusion without relative bias between the two species. The $t^{-1/3}$ behavior, in particular, has so far been observed exclusively in systems with hardcore exclusion. Here we construct a model of particles without hardcore exclusion that reproduces this same $t^{-1/3}$ scaling. In our model, both species undergo asymmetric
diffusion with a rate that depends nonlinearly on the local density, a form of transport that, in the absence of the other species, is superdiffusive and falls into the Kardar-Parisi-Zhang universality class. The scaling behavior of $t^{-1/3}$ occurs when at least one of the two species undergoes asymmetric
diffusion induced by microscopic processes involving pairs of particles, while asymmetric processes involving groups of three particles lead to $t^{-1/4}$ scaling associated with symmetric
diffusion. This demonstrates that the pair annihilation density decay exponent is not determined exclusively by the transport properties of the isolated particle species.
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Quantum Physics
Gate-Efficient Implementation of the Query-Optimal Time-Dependent Hamiltonian Simulation
Boyang Chen, Minbo Gao, Zhengfeng Ji et al. (+3 more)
The query-optimal
algorithm of [CGWZ26] for general time-dependent
Hamiltonian simulation uses $$ q = O\left( \alpha T + \frac{\log(1/\varepsilon)}{\log\left(e + \log(1/\varepsilon)/(\alpha T) \right)} \right) $$ queries to $\mathrm{HAM\mbox{-}T}$ within $\varepsilon$ error for a Lipschitz-continuous time-dependent
Hamiltonian $H(t)$ on $[0,T]$ satisfying $\left\lVert H(t)\right\rVert\leq\alpha$. However, its direct
circuit implementation incurs a substantially larger gate overhead. In this note, we give an implementation of the same
algorithm that retains its optimal query complexity and uses $$ O\left[ q \left( a + \log\left(1 + \frac{T(\alpha + \beta T)}{\varepsilon} \right) \right) \right] $$ one- and two-
qubit gates, where $a$ is the number of block-encoding ancilla
qubits and $\beta$ is the Lipschitz constant of $H$. The main ingredient is an exact dyadic factorization of the ordered update product in the underlying one-query transducer.
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All authors Boyang Chen, Minbo Gao, Zhengfeng Ji, Tongyang Li, Xinzhao Wang, Shuo Zhou
Mesoscale and Nanoscale Physics
Predictive wavelength tailoring of uniform GaSb-based quantum dots for emission at 1.55 um
Markus Peil, Maja Wasiluk, Ziemowit Olinkiewicz et al. (+11 more)
A detailed study of emission wavelength tailoring of GaSb-based QDs formed by InGaSb-filling of droplet-etched nanoholes in AlGaSb is presented. The study shows that the emission wavelength can be modified from 1.48 um to the center of the telecom C-band at 1.55 mm by independently varying the QD composition and size. More specifically, the optical transition energy shifts linearly as a function of In-content of the QD material at a rate of -4.4 meV/In-percentage, and with the number of monolayers (ML) of material used for filling the nanoholes, at -2.0 meV/ML. These experimentally observed energy shifts are well predicted by simulations yielding rates of -4.3 meV/In-percentage and -2.1 meV/ML, respectively. For the simulation, a uniform In composition, low intermixing, and microscopically measured QD geometry is considered. Additionally, excellent ensemble QD uniformity, with unprecedented inhomogeneous broadening well-below 7 meV across all samples is demonstrated. Finally, photoluminescence of single-QDs reveals narrow excitonic emission lines of 13.8+/-6.7 ueV and low fine-structure splitting values reaching <10 ueV. These results identify GaSb-based LDE QDs as a tunable telecom platform for scaling
quantum-photonic applications over long-haul optical fiber networks.
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All authors Markus Peil, Maja Wasiluk, Ziemowit Olinkiewicz, Tymon Przychodni, Robert Matysiak, Teemu Taskinen, Joona Salonen, Abhiroop Chellu, Metin Patli, Joonas Hilska, Anna Musiał, Michał Gawełczyk, Mircea Guina, Teemu Hakkarainen
Applied Physics
A model-inversion control strategy to attain desired equilibrium points when synthesizing nonlinear resonators
Maxime Morell, Emanuele De Bono, Emmanuel Gourdon et al. (+3 more)
The initial conditions of a deterministic nonlinear system affects the attained asymptotic solutions. This is a problem when the nonlinear behaviour is achieved by active control synthesis, and the initial conditions are not accessible for pre-constraining. Meanwhile, the generalized impedance control is recently gaining increasing
attention in acoustics, and has been enlarged to achieve nonlinear mechanical responses of Electroacoustic Resonators at low excitation levels. Nevertheless, as the initial conditions of Electroacoustic Resonators are hardly accessible, the
equilibrium points actually showcased by the synthetic nonlinear dynamics are not advantageous for noise attenuation in cavities excited by realistic noise sources. In this paper, we propose a control strategy being able to attain the desired
equilibrium points, due to the definition of an exosystem characterized by a desired nonlinear impedance and a synthetic external excitation. The exosystem dynamics is integrated in real time and its response is enforced in the actual system (in our case, the Electroacoustic Resonator), by a model-inversion feedforward strategy. The proposed
algorithm is implemented in the Electroacoustic Resonator, and is validated both numerically and experimentally. In particular, the experimental testing is conducted both in a quasi-open acoustic environment, and in enclosed cavities for acoustic mode attenuation.
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All authors Maxime Morell, Emanuele De Bono, Emmanuel Gourdon, Manuel Collet, Alireza Ture Savadkoohi, Claude-Henri Lamarque
Statistical Mechanics
Time-delayed feedback turns Arrhenius escape logarithmic
Roy Podgaetsky, Vishwajeet Kumar, Arnab Pal et al. (+1 more)
Thermal escape is governed by the Arrhenius law, where the mean escape time scales exponentially with the barrier height. We show that the non-Markovianity induced by time-delayed feedback in the confining force removes this exponential scaling. Beyond a threshold set by the
curvature of the minimum, the delay destabilizes the well, and the thermal noise seeds an instability that is subsequently amplified deterministically to the boundary leading to slingshot escape trajectories. The escape time becomes logarithmic in the barrier, its fluctuations follow a Gumbel law, and an optimal delay enables escape faster than free
diffusion. Our results propose time delay as a tunable and experimentally feasible control parameter for accelerating activated processes.
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All authors Roy Podgaetsky, Vishwajeet Kumar, Arnab Pal, Ohad Shpielberg
Quantum Physics
Efficient measurement schemes for the Monte Carlo projective quantum eigensolver
Divye Baid and Maria-Andreea Filip
The Monte Carlo Projective
Quantum Eigensolver (MC-PQE) was recently introduced as an alternative to hybrid
algorithms like the variational
quantum eigensolver (VQE). By using a
quantum Monte Carlo-inspired scheme for energy estimation, MC\nobreakdash-PQE was found to decrease the required measurement cost relative to comparable conventional approaches. However, in the context of VQE, numerous techniques have been developed to reduce the measurement overhead by joint measurement of multiple observables. In this work, we extend these approaches to the asymmetric expectation values required in MC-PQE and assess the performance of different techniques for various molecular systems of up to 12
qubits. We find full commuting Pauli term grouping combined with tailored measurement allocation techniques leads to a 5-10$\times$ reduction in standard error for the same total number of
quantum measurements. Conventional
Hamiltonian grouped measurement outperforms tractable classical shadows
tomography based techniques for the considered systems.
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Atmospheric and Oceanic Physics
Universal ordinary differential equations and the parameterization of warm-rain processes
Axel Seifert
The parameterization of warm-rain formation is a long-standing problem in cloud microphysics because the
evolution of bulk cloud variables cannot be derived uniquely from the kinetic collection equation (KCE). Universal ordinary differential equations (UODEs)provide a scientific machine learning framework that combines neural networks with ordinary differential equations and can learn dynamical operators directly from time series. Here, the UODE framework is applied to warm-rain formation by training on trajectories generated with a super-droplet model that approximates the KCE. In contrast to most previous machine-learning approaches, only the prognostic state variables are used for training, without requiring autoconversion or
accretion rates as targets. The learned closure accurately reproduces the KCE trajectories within the training domain and, although not explicitly constrained to do so, yields autoconversion and
accretion rates that closely resemble those diagnosed from the KCE. Analyzing the learned operator provides new insight into the structure of the widely used Seifert and Beheng (2001) warm-rain parameterization. In particular, it suggests that the empirical suppression of
accretion primarily compensates for an overestimation of autoconversion at small rain fractions. Motivated by these findings, a refined analytical formulation is proposed that improves agreement with the KCE while retaining the simplicity of the original parameterization. The results demonstrate that UODEs can serve not only as accurate surrogate models but also as a tool for understanding and improving analytical parameterizations of cloud microphysical processes.
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High Energy Physics (Phenomenology)
Hadron interactions in the U-70 energy range: results and problems
V. A. Petrov and N. P. Tkachenko
From late 1967 until the early 1970s, the Soviet
proton synchrotron (better known as the Serpukhov accelerator or U-70), with a nominal laboratory energy of up to 76 GeV, was the world leader. During these few years, several results of fundamental significance were obtained (partially in collaboration with physicists from CERN, France, and other countries). Let us briefly outline the main provisions of the paradigm that reigned at that time in the field of strong interaction theory.
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Mathematical Physics · Cross-listed from math.AP
Endpoint Mapping Properties of Wave Operators for Two-Dimensional Schrödinger Operators
Han Cheng, Changxing Miao and Xiaohua Yao
We establish sharp endpoint mapping properties for the wave operators $W_\pm(H,-\Delta)$ of two-dimensional Schrödinger operators $H=-\Delta+V$ with real-valued decaying potentials $V$. Together with the known non-endpoint $L^p$ theory, our results give a complete classification of the $L^p$ mapping properties of the two-dimensional wave operators, and reveal an unexpected reversal of the usual threshold paradigm at the endpoints $p=1$ and $p=\infty$. When zero is a regular point of $H$, the wave operators fail to be bounded on $L^1(\mathbb{R}^2)$ and on $L^\infty(\mathbb{R}^2)$, but they satisfy the atural substitute estimates of Calderón–Zygmund type: $$ L^1(\mathbb{R}^2)\longrightarrow L^{1,\infty}(\mathbb{R}^2),\ \ \ \mathcal{H}^1(\mathbb{R}^2)\longrightarrow L^1(\mathbb{R}^2),\ \ \ L^\infty(\mathbb{R}^2)\longrightarrow \mathrm{BMO}(\mathbb{R}^2). $$ When zero is instead a threshold singularity of the first kind—an s-wave resonance with no other threshold obstruction, the wave operators are bounded on both endpoint spaces $L^1(\mathbb{R}^2)$ and $L^\infty(\mathbb{R}^2)$. Thus, in dimension two, an s-wave resonance improves the endpoint behavior of the wave operators, in sharp contrast with dimensions $n\ge3$, where the only regular case is the favorable one. We also determine the endpoint behavior in the remaining zero-energy spectral configurations of $H$. A p-wave resonance obstructs both the $L^1$- and the $L^\infty$-boundedness of the wave operators, while in the zero-
eigenvalue case we obtain necessary and sufficient conditions for endpoint boundedness, expressed in terms of the presence of s- and p-wave resonances and of explicit second-order harmonic moment cancellations satisfied by the zero-energy eigenfunctions.
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Materials Science
Layer Axial Phonons and Dipolar Thermal Response in Centrosymmetric Thin Films
Madhubanti Mukherjee, Kapil Gope and Barun Ghosh
In nonmagnetic centrosymmetric materials, $\mathcal{PT}$
symmetry enforces vanishing total
phonon angular momentum (
phonon AM) at every wave vector, making them appear unsuitable as hosts of axial
phonons. Here, using first-principles calculations for BaAgAs and representative van der Waal's layered materials, we show that centrosymmetric slabs can still host large hidden layer-resolved
phonon AM with both
chiral and cycloidal modes. This hidden
phonon AM texture produces layer resolved
phonon thermal Edelstein-like responses and a real-space
phonon AM dipole response, both tunable by strain. Our results establish centrosymmetric layered materials as an exciting platform for hidden axial
phonon and multipolar
phonon thermal response.
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Cosmology and Nongalactic Astrophysics
Not all those missing are lost: leveraging galaxy clustering in incomplete catalogs to unleash dark sirens cosmology
Riccardo Barbieri, Marios Kalomenopoulos, Matteo Tagliazucchi et al. (+2 more)
Gravitational waves offer a unique opportunity to solve the Hubble tension. In order to do so, we have to extract as much information as possible from cross correlating gravitational wave events (used as "dark sirens") with incomplete
galaxy catalogs. Traditional methods assume a uniform in comoving volume distribution for
galaxies missing from the catalogs, which neglects the fact that
galaxies tend to cluster, leading to less precise and possibly biased posteriors. In this paper, we introduce a new method for accounting for
galaxy clustering when dealing with an incomplete
galaxy catalog, by adding back
galaxies to the incomplete catalog and distributing them in pixels according to the correlation function $\xi(r)$. We find that our method drastically improves on traditional ones when the
galaxy catalog is only $1\%-10\%$ complete, leading to posteriors that are between 2 and 4 times as precise, depending on the completeness fraction, without introducing any biases. Our method produces results comparable to traditional methods at extremely low catalog completeness fractions (<0.5%) or for very high uncertainties in the recovered luminosity distance and sky localization of the gravitational wave events.
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All authors Riccardo Barbieri, Marios Kalomenopoulos, Matteo Tagliazucchi, Jonathan Gair, Sadegh Khochfar
Superconductivity
Quadratic pair-breaking absorption edge from Anderson localization in a superconducting wire
Bahruz Suleymanli and B. Tanatar
We show that Anderson localization fundamentally reshapes dissipative superconducting electrodynamics, replacing the linear Mattis–Bardeen pair-breaking onset with a parametrically weaker quadratic Mott edge while leaving the quasiparticle spectrum unchanged. We derive this behavior for a weakly disordered single-channel wire with a spatially uniform $s$-wave pair potential using a Nambu-space extension of the Berezinskii diagram technique that resums elastic
impurity scattering to all orders. Conservation of the Bogoliubov branch collapses the Nambu diagram hierarchy onto an exactly solvable localization problem. The localization length remains equal to its normal-state value, whereas the localization time diverges at the gap edge. The new absorption edge results from the product of the superconducting pair-creation coherence factor and the Mott-suppressed current
matrix elements between localized orbitals, which generates the characteristic double logarithm. Localization also reduces the Hebel–Slichter coherence peak. The resulting theory provides an all-orders
benchmark for microwave and
spin-relaxation experiments on localized superconducting nanowires.
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High Energy Astrophysical Phenomena
TeV Gamma Rays and Neutrinos from Winds Driven by Radiatively Inefficient Accretion Flows of Low-Luminosity Active Galactic Nuclei
Nobuyuki Sakai, John F. Beacom and Kohta Murase
Recently, the Large High Altitude Air Shower Observatory (LHAASO) reported the first TeV gamma-ray detection from a low-luminosity active
galactic nucleus (LLAGN) lacking a strong jet. This source, NGC 4278, is one of the nearest LLAGNs that can be studied in detail as a template for more distant objects. Most previous studies have focused on the month-scale-variable gamma-ray activities, seeking to explain them with weak jets. We focus instead on NGC 4278's quiet-period emission, proposing a different mechanism based on a wind launched from a radiatively inefficient
accretion flow (RIAF). In particular, we model particle acceleration at a wind-driven shock and calculate the resulting multimessenger emission. To match the TeV gamma-ray fluxes reported by LHAASO in the quiet period, our model requires a wind power of $\lesssim2\times10^{43}~\mathrm{erg~s^{-1}}$ with a spectral index of injected
cosmic rays of 2.0. We show that this is achievable through Bondi
accretion of the ionized gas observed on the 100-pc scale, for a shallow
accretion profile. We discuss the testability of our wind-driven shock scenario with multimessenger observations. As another important application, we extend our model to Sgr A*, the nearest LLAGN, and show that its TeV gamma-ray emission is reproduced with reasonable parameters. Our results suggest that RIAF-driven winds may be a generic emission mechanism in LLAGNs, making this class a potentially important population of both gamma-ray emitters and
cosmic-ray accelerators.
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Instrumentation and Methods for Astrophysics
Learning Radio Astronomical Representations with LeJEPA and Very Small Models
Erica Lastufka, Mariia Drozdova, Vitaliy Kinakh et al. (+4 more)
Representations learned by
vision foundation models pretrained on natural images have been shown to be useful for out-of-domain astronomical images. Performance on scientific downstream tasks increases with model size, which both carries higher inference costs and limits scalability, even when considering parameter-efficient adaptation. An alternative is to learn representations directly from astronomical observations rather than natural images, through self-supervised pretraining. We evaluate LeJEPA's ability to learn robust representations using very small
vision models ($\sim$6M parameters) pretrained on
Radio Galaxy Zoo images, comparing with established self-supervised frameworks. We test whether LeJEPA's latent-space regularization leads to better
radio galaxy morphology classification. Across three evaluation
datasets, LeJEPA achieves performance comparable to a substantially larger foundation model while producing more consistent representations across training and evaluation
datasets. These results suggest that the choice of representation learning objective is critical for enabling small domain-specific models to achieve performance competitive with representations transferred from large foundation models in scientific imaging.
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All authors Erica Lastufka, Mariia Drozdova, Vitaliy Kinakh, Taras Holotyak, Miroslava Dessuages-Zavadsky, Daniel Schaerer, Svyatoslav Voloshynovskiy
Materials Science
Freezing of a deformable water-saturated porous medium. Part I: THM formulation, OpenGeoSys-6 implementation and benchmarking
Tymofiy Gerasimov, Christian B. Silbermann, Dmitri Naumov et al. (+3 more)
In this contribution, Part I, we present a coupled thermo-hydro-mechanical formulation for modeling and analyzing water-to-ice phase change in a deformable fully-saturated porous medium. It is implemented in the multi-physics computational platform OpenGeoSys-6. We compute a series of carefully designed
benchmark problems which critically examine the corresponding formulation components and the overall implementation. Several ingredients that have a qualitative and quantitative impact on the numerical results are identified, particularly dissected and commented on. Simulations also account for soil deformation induced by freezing (as a result of 9% volumetric expansion caused by water-to-ice phase transition). The forthcoming Part II will complete the code verification and validation campaign by considering a real full-scale three-dimensional case study of shallow subsurface ice storage. More specifically, we simulate the ice growth process in a fully saturated soil specimen surrounding a group of borehole heat exchangers (BHEs) that contain subzero temperature coolant fluid. A snapshot of the numerical results of this task is already depicted here in Part I as a teaser.
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All authors Tymofiy Gerasimov, Christian B. Silbermann, Dmitri Naumov, Olaf Kolditz, Haibing Shao, Thomas Nagel
Atmospheric and Oceanic Physics
Ice-thickness based scaling of wave attenuation in sea ice: Application and assessment of wave spectra
W. Erick Rogers, Jie Yu, Jean Rabault et al. (+2 more)
This study discusses recent advances in modeling waves in sea ice in the U.S. Navy's regional modeling system. It is applied in the marginal seas of the eastern Arctic Ocean, including the Barents Sea, Kara Sea, parts of the Greenland Sea, Norwegian Sea, and waters north of Svalbard. The focus is to assess the skills of two formulations of wave attenuation by sea ice used operationally in WAVEWATCH III. Both are derived from large field
datasets, one from the Arctic and the other from the Antarctic. The new model (IC4M9) describes wave attenuation depending on the ice thickness in association with the dependence on wave frequency, while the earlier default scheme (IC4M6) omits the dependence on ice thickness. The modeling results are evaluated against the satellite wave observations from SWIM/CFOSAT and the buoy measurements from the Svalbard Marginal Ice Zone 2024 Campaign (SvalMIZ-24). The comparisons with SWIM data validate the wave model skill in regions of open water or with light ice coverage. When evaluated against the SvalMIZ-24 data, the statistical performance of IC4M9 is substantially better than that of IC4M6, showing the influence of ice thickness on waves in the MIZ. Moreover, diagnosing systematic errors in the predictions by IC4M9, we find that the ice thickness field provided by the sea ice model CICE to the wave model is biased high in the MIZ, thus penalizing the performance of IC4M9 while not affecting the model IC4M6, which depends on frequency only.
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All authors W. Erick Rogers, Jie Yu, Jean Rabault, Ana Carrasco, Malte Müller
Superconductivity
Machine learning reveals common features of unconventional superconductors with high transition temperatures
Haosheng Xu, Dongheng Qian, Yijun Yu et al. (+1 more)
Superconductors with high critical temperatures that emerges beyond the
phonon-mediated regime are usually considered unconventional in nature, yet unlike conventional
superconductors, no broadly applicable predictive theory currently guides their discovery. Here, we use interpretable machine learning to uncover a common materials-space signature of high-$T_{\mathrm{c}}$ unconventional
superconductors and develop a data-driven strategy for materials discovery. We construct a unified feature representation for each material by integrating compositional statistics, structural information, and latent representations from trained property-prediction models, followed by structure-aware filtering of an experimentally established superconducting
dataset. Without using transition-temperature information, unsupervised analysis shows that cuprate and iron-based
superconductors occupy a common region of materials space, characterized primarily by large electronegativity deviation and intermediate mean valence-electron number. A supervised $T_{\text{c}}$ model independently identifies the same descriptors as dominant features, providing complementary evidence for their relevance. Using this empirical materials-space prior together with the $T_{\text{c}}$ model, we prioritize candidate materials, recover recently discovered nickelate
superconductors, and identify chemically distinct candidates for future investigation.
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All authors Haosheng Xu, Dongheng Qian, Yijun Yu, Jing Wang
Nuclear Theory
NS-UNO: Neutron Star EoS Inference from an Unconstrained Number of Observations
Valéria Carvalho, Márcio Ferreira, Michał Bejger et al. (+1 more)
Future multimessenger observations of
neutron stars (NS) are expected to substantially increase both the number and precision of astrophysical constraints on the equation of state (EoS) of dense matter. This motivates inference frameworks capable of accommodating a variable, non fixed number of observations while preserving the posterior information associated with each measurement. In this work, we introduce NS-UNO, a Neural Posterior Estimation framework for NS EoS inference designed to accommodate an Unconstrained Number of Observations (UNO). NS-UNO combines a hierarchical DeepSets model with a conditional normalising flow, enabling a single trained model to perform inference from mass-radius observation sets of varying size, with each observation represented by a set of posterior samples. We demonstrate accurate and well calibrated posterior reconstructions using a model trained jointly on piecewise polytropic and non-parametric Gaussian process EoS ensembles. The reconstruction improves as observations probe a broader range of NS masses, while remaining robust to variations in the number and precision of the observations. The model also generalises to EoSs outside the families used during training. Finally, we qualitatively demonstrate the framework on current multimessenger constraints from NICER and GW170817. NS-UNO provides a flexible and scalable approach to NS EoS inference, naturally suited to the increasingly diverse observational
datasets expected from next generation multimessenger astronomy.
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All authors Valéria Carvalho, Márcio Ferreira, Michał Bejger, Constança Providência
Soft Condensed Matter
A closed-form theory of charge-regulated electrostatic interactions between anisotropically charged spheres
Anže Božič
Proteins and many other colloids carry ionizable surface groups that are both spatially inhomogeneous (patchy) and pH-responsive (charge-regulating). In the description of the electrostatic interactions between such particles, these two aspects are often treated separately, especially from a theoretical perspective. We present a unified, closed-form theory that unites charge regulation and patchiness within the linearized Poisson–Boltzmann approximation. For spherical particles with anisotropic distributions of titratable sites, we derive both the leading-order mean-field interaction energy as well as the Kirkwood–Shumaker fluctuation interaction. The theory exposes a qualitatively new effect between two electroneutral anisotropic particles: proximity-induced charge regulation generates a net monopole, and splits orientational branches that are {mirror-symmetric} in any linear fixed-charge model. The accompanying correction to the interaction energy has no fixed sign—it weakens like-charge repulsion but can deepen an existing attraction or create one where fixed charge predicts none. We
benchmark three components of the theory against published results, as no existing simulation probes their combination, which would capture the central prediction of the theory. Lastly, we apply the theory to two
proteins—lysozyme and $\alpha$-chymotrypsinogen A—and show that it not only reproduces the general trends of the measured second virial coefficients but also predicts how charge regulation expands the range of pH and screening strength where the
protein–
protein interaction is attractive.
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Computational Physics
OpenMUSTANC (MUltiple Scattering Theory At Nanoplasmonic Cavities): A MATLAB toolbox for the simulation of Plasmonic Sphere Aggregates
Xin Zheng, Christos Mystilidis, Christos Tserkezis et al. (+2 more)
Mesoscopic physical models, including the Hydrodynamic Drude Model (HDM), the Generalized Nonlocal Optical Response (GNOR) Model, and the Surface Response Model (SRM), have been proposed to investigate nonlocal effects in nanometric structures. The combination of classical electromagnetism with these mesoscopic material models calls for new computational electromagnetic (CEM)
algorithms, or update of conventional ones, in what is termed computational mesoscopic electromagnetics (CMEM). In this work, we present a MATLAB toolbox for the simulation of multiple spherical interfaces with arbitrary relative positions, with the incorporation of the aforementioned mesoscopic models. The method exploits vector spherical wave functions to properly express electric and
magnetic fields, an S
matrix formulation for the efficient treatment of incident and scattered fields at spherical interfaces, and a translation
matrix to deal with propagating waves with different expansion centers. Excitation sources can be chosen among arbitrarily polarized plane waves, dipoles and electron beams. For the post-processing part, the calculation of cross sections and far/near-field mapping; fluorescence enhancement, Purcell factor and
quantum yield; and cathodoluminescence and electron energy-loss probability is implemented. The toolbox is built in a modular manner, and each part (routine) has its own important functionality. This paper provides a full explanation of the proposed highly efficient and general toolbox, and a detailed guideline for researchers in the nanoplasmonics community.
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All authors Xin Zheng, Christos Mystilidis, Christos Tserkezis, Guy A. E. Vandenbosch, Xuezhi Zheng
High Energy Astrophysical Phenomena
Cascades from ultra-high-energy neutrinos
Gaetano Di Marco, Rhorry Gauld, Rafael Alves Batista et al. (+2 more)
Neutrinos produced at the highest energies can interact with
cosmic neutrino and radiation backgrounds during their propagation to Earth. The many available $\nu\nu$, $\nu\bar{\nu}$, and $\nu\gamma$ channels can lead to their absorption or energy redistribution, whilst the leptonic and hadronic final states may feed secondary fluxes of
neutrinos,
protons, and electromagnetic particles through the decay or hadronisation of the heavy
leptons,
bosons, and
quarks produced. We present a framework to characterise these propagation effects in detail, \texttt{$\nu$propa}, an extension of the CRPropa Monte Carlo code that interfaces with event generators and to dedicated computations of the relevant cross sections. It also treats flavour oscillations in
vacuum. Using this code, we investigate sources at high
redshifts ($z = 10$), and find a strong absorption of the
prompt flux beyond~$\sim 10^{21} \; \text{eV}$, although the copious secondary
neutrinos partially compensate this depletion, also contributing to the spectrum at lower energies. The framework is designed to study scenarios of cosmological
neutrino production beyond~EeV energies such as superheavy dark matter,
cosmic strings, and
primordial black holes, and to yield reliable predictions for the forthcoming
neutrino observatories.
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All authors Gaetano Di Marco, Rhorry Gauld, Rafael Alves Batista, Alfonso García-Soto, Miguel Á. Sánchez-Conde
High Energy Physics (Phenomenology)
Charmonium production in p+A collisions at SPS and FAIR energies
Taesoo Song, Jiaxing Zhao, Joerg Aichelin et al. (+1 more)
We employ the Parton-
Hadron-String Dynamics (PHSD) transport approach to investigate the influence of
baryon-rich matter on charmonium production and dissociation. The Remler formalism is implemented to dynamically model charmonium formation from charm-anticharm pairs. As a validation step, the formalism is first benchmarked against experimental data from elementary pp collisions and then extended to pA systems to extract the effective
nuclear absorption cross section of charmonium. This extracted cross section can subsequently be applied in heavy-ion collisions to quantify medium-induced effects. Our results demonstrate that the Remler formalism provides a quantitatively consistent description of charmonium production in pp and pA collisions at SPS energies. The approach is then extrapolated to GSI/FAIR energies, where predictions for charmonium yields and survival probabilities are presented. These findings highlight the relevance of the Remler formalism as a dynamical framework for studying heavy-
quark bound-state formation in
baryon-rich matter and offer theoretical guidance for future experimental programs at SPS, FAIR and NICA aimed at mapping the QCD phase structure.
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All authors Taesoo Song, Jiaxing Zhao, Joerg Aichelin, Elena Bratkovskaya
Solar and Stellar Astrophysics
Interferometric Survey of Stellar Parameters: Towards homogeneous FGK stars parameters and surface-brightness color relation in the context of PLATO space mission
Romina V. Ibañez Bustos, Denis Mourard, Nicolas Nardetto et al. (+20 more)
The estimation of
stellar angular diameters can be performed from the surface brightness - color relation (SBCR) and photometry. The SBCR have been considered by the PLATO space mission as an independent empirical alternative for estimating
stellar radii of FGK
stars. In this context, we have implemented an homogeneous approach not only for calibrating the SBCR for FGK-IV/V
stars but, also for determining their fundamental parameters in order to place the
stars reliably on the HR diagram and to study their impact on the SBCR. We have performed interferometric observations of 18 quiescent FGK-IV/V
stars in the
Gaia color range of $3.088 \leq G \leq 5.498$. For the first time, we used 3 different interferometers operating in the $R$, $H$ , and $K$ bands to measure polychromatic limb-darkened angular diameters (LDAD). In parallel, by using public domain spectra we have estimated the
stellar parameters ($T_{eff}$, $log g$ and Z) by using the open python tool iSpec. We achieved an average accuracy of 2.3% for the LDAD based on polychromatic observations. However, we have observed that our SBCR does not follow the calibration of the relation between surface brightness and color in
Gaia found in the literature. Furthermore, we found that $log g$ and $Z$ have no impact on the SBC relation; given the characteristics of our sample of quiescent
stars, it constitutes an ideal set of targets for conducting a new SBCR calibration within the framework of the PLATO space mission. In this context, we reported a SBCR calibration with $\sigma_{RMS} = $ 0.012, 0.009, 0.009 in the $G, G_{BP}$ and $G_{RP}$
Gaia bands, respectively. This article is part of a series of papers reporting the first results obtained using a polychromatic approach to measure LDAD, employing a fully homogeneous methodology for both determining the fundamental parameters of
stars and measuring the LDAD, $\theta_{LD}$.
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All authors Romina V. Ibañez Bustos, Denis Mourard, Nicolas Nardetto, Jeremy Jones, Nayeem Ebrahimkutty, Juraj Jonák, Hugo Nowacki, Mathieu Vrard, Philippe Berio, Julien Dejonghe, Roxanne Ligi, Frédéric Morand, David Salabert, Orlagh Creevey, Armando Domiciano de Souza, Manon Bailleul, Karine Perraut, Markus Wittkowski, John D. Monnier, Stefan Kraus, Narsireddy Anugu, Mayra Gutierrez, Noura Ibrahim
Materials Science
Heterogeneous ferroelectricity and conductivity of oxidized BaTiO$_3$ crystals: the role of nanoscale phase segregation in the surface region
Christian Rodenbücher, Gustav Bihlmayer, Susan Trolier-McKinstry et al. (+3 more)
We investigate the effect of thermal oxidation on BaTiO$_3$ single
crystals. Our results reveal that, even at moderate temperatures of up to 1000 {\deg}C, complex segregation mechanisms occur involving the movement of Ba-rich compounds to the upper surface, where they form inhomogeneously distributed BaO nanocrystals. As a result, deeper regions of the surface layer become depleted in Ba and become TiO$_2$-rich. A sandwich-like structure evolves in the surface layer, exhibiting a measurable electromotive force and self-polarization. This, in turn, screens the polarization and diminishes the global ferroelectric response. The conductivity is also strongly influenced by the irreversible segregation effects in the surface region. An as-received
crystal can be transformed into a metallic state, while oxidation induces semiconducting properties and prevents a return to the metallic state upon subsequent reduction. Nanoscale analysis demonstrates that the conductivity is channeled to filaments forming along dislocations, whose local chemical composition changes upon reduction and oxidation even at moderate temperatures due to preferential Ba and O pipe
diffusion thus determining the electric behavior of the whole sample.
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All authors Christian Rodenbücher, Gustav Bihlmayer, Susan Trolier-McKinstry, Jacek Szade, Franciszek Krok, Kristof Szot
Other Condensed Matter
Temperature Dependence of the Refractive Index for AlAsGaSb
Helena Janowska, Wojciech Charaszkiewicz, Maja Wasiluk et al. (+6 more)
Accurate design and optimization of photonic multilayer structures like distributed Bragg reflectors (DBRs) require precise knowledge of material optical constants, particularly the temperature dependence of the refractive index. While these parameters are well established for widely used
semiconductors, for emerging materials such as antimonides they are often limited to room-temperature data, especially for new spectral ranges of interest. Antimonide compounds, in particular GaSb-based
alloys, are promising for
quantum photonics applications. In this work, we investigated DBRs
lattice-matched to GaSb and designed for operation in the third telecommunication window. Reflectivity spectra were measured in the temperature range from 11.5 K to 300 K, and then fitted using the transfer
matrix method (TMM), combined with a dedicated recursive numerical fitting
algorithm. Initial parameters included layer thicknesses determined by scanning electron microscopy (SEM) and literature values of refractive indices at room temperature. This approach enabled extraction of the temperature-dependent refractive indices of two AlGaAsSb
alloys suitable for forming DBR mirrors for 1.5 um wavelengths. The obtained results provide essential input for reliable DBR design, ensuring proper stopband positioning and high reflectivity under cryogenic operating conditions required for efficient
quantum emitter performance.
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All authors Helena Janowska, Wojciech Charaszkiewicz, Maja Wasiluk, Markus Peil, Teemu Taskinen, Joonas Hilska, Abhiroop Chellu, Teemu Hakkarainen, Anna Musiał
Solar and Stellar Astrophysics
Joint Observations of PTPS Targets (JOTA). Combined spectroscopic and photometric analysis of 16 SB1 systems
Robert Jaros, Andrzje Niedzielski, Sohaib Ali et al. (+9 more)
Context. The Pennsylvania-Toruń
Planet Search, which operates on a sample of $\sim$1000 northern-hemisphere
stars, has been underway since 2004.
Stars with radial velocity (RV) amplitudes exceeding 2 km s$^{-1}$ represent a backup subprogram sample dedicated to monitoring binary
stars with multiple instruments. Aims. We used almost 21 years of combined RV measurements to search for Doppler signals consistent with
stellar or brown
dwarf companions and to produce a catalog of both known and previously unpublished binary
stars in our
planet-search sample. Methods. We analyzed the combined RV measurements, searching for
stellar companions and obtaining orbital solutions for both known and new binary systems. We also searched for periods in available long-term photometric monitoring data from All Sky Automated Survey (ASAS), and applied
Gaia astrometric data whenever available. Results. We report the results of long-term RV monitoring of 16 systems: new detections of low-mass companions to 11
stars and updated orbital elements based on combined sets of our new and literature data for five systems. For two objects (TYC 3318-00789-1 and TYC 3318-01538-1), we find evidence of activity or the influence of another unseen companion, possibly due to line-profile variations or unresolved spectral contamination. We present true masses for three systems in our sample: TYC 1931-1040-1, TYC 3451- 1449-1, and TYC 3667-1636-1. We obtained these masses using
Gaia DR3 non-single
star data.
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All authors Robert Jaros, Andrzje Niedzielski, Sohaib Ali, Divyansh Srivastava, Julia Sierzputowska, Monika Adamów, Jorge Lillo-Box, Dmytro Orikhovskyi, Aleksander Wolszczan, Eva Villaver, Theodor Pribulla, Martin Vaňko
Fluid Dynamics
Evolution of inertial particle clustering in decaying turbulence
Martín Obligado and Sofía Angriman
Inertial particle dynamics in
turbulence are commonly interpreted in terms of the instantaneous particle Stokes number, as supported by studies in statistically stationary homogeneous isotropic
turbulence. But in freely decaying
turbulence the Kolmogorov time scale evolves continuously, causing the effective Stokes number, St, to vary even though particle properties remain unchanged. Whether preferential concentration remains uniquely determined by this instantaneous St or depends on the flow's previous
evolution has remained largely unexplored. We investigate inertial-particle clustering during the decay of homogeneous isotropic
turbulence using direct numerical simulations of heavy point particles in the one-way coupling limit. Clustering is quantified through 3D Voronoï tessellations for populations evolving either from statistically stationary clustered states or initially random distributions. We consider both conventionally forced homogeneous isotropic
turbulence and velocity fields reconstructed using physics-informed neural networks. We show that preferential concentration cannot be described solely by the instantaneous St. While particle slip velocity follows the classical steady-state dependence on the instantaneous St, clustering statistics retain a measurable history dependence throughout decay. Existing stationary scaling laws remain applicable to cluster-size
evolution, but only through history-dependent prefactors. Particle distributions evolving from different initial conditions rapidly converge towards similar large-scale spatial organisation, indicating that the carrier flow determines the geometry of preferential concentration while finer clustering statistics preserve imprints of the previous
evolution. These results demonstrate that preferential concentration in non-stationary
turbulence is governed jointly by the instantaneous flow state and its initial state.
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Quantum Gases
Mass-gap functional determinant approach for mobile Fermi polarons
Emilio Ramos Rodríguez, Eugen Dizer, Xin Chen et al. (+1 more)
We extend the functional determinant approach (FDA), previously restricted to static
impurities, to the case of finite-mass
impurities by using the mass-gap description of
Fermi polarons [Phys. Rev. Lett. 135, 193401 (2025)]. The quadratic structure of the mass-gap model enables the exact evaluation of many-body spectra and Ramsey dynamics for mobile
impurities. We show that this mass-gap FDA smoothly interpolates between the
Fermi-edge singularity for infinitely heavy
impurities and the emergence of quasiparticle weight for finite
impurity mass. Our results demonstrate that the mass-gap FDA provides a transparent and computationally efficient framework to describe the
quantum dynamics of mobile
impurities.
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All authors Emilio Ramos Rodríguez, Eugen Dizer, Xin Chen, Richard Schmidt
Mesoscale and Nanoscale Physics
Exact fluctuation relations in voltage- and temperature-biased Laughlin-edge constrictions
Gu Zhang, Gabriele Campagnano, Domenico Giuliano et al. (+2 more)
We present a comprehensive analysis of non-
equilibrium fluctuation-dissipation relations connect- ing experimentally accessible
chiral-current auto- and cross-correlations to the tunneling-current noise and conductance in Laughlin edge states coupled through a
quantum point contact (QPC). We examine their validity for two
chiral Laughlin edges held at different temperatures and voltages and show that the relations remain exact for arbitrary tunneling strength, voltage bias, and edge- state temperatures. We further generalize them to spatially extended QPCs and to tunneling am- plitudes with an explicit voltage dependence, and discuss the conditions and limitations associated with these generalizations. Our results establish that the local tunneling-current noise generated at the QPC can be reliably reconstructed from experimentally accessible auto- and cross-correlations measured downstream, providing a robust route to characterize non-
equilibrium transport in
chiral edge states.
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All authors Gu Zhang, Gabriele Campagnano, Domenico Giuliano, Igor Gornyi, In`es Safi