Quantum Physics · Cross-listed from cs.CR
Indistinguishability Lifting for Keyed Oracles, Compressed Ideal Cipher, and More Applications
Ritam Bhaumik and Yu-Hsuan Huang
Cryptographic security proofs often involve an adversary interacting with a larger, keyed oracle that consists of (potentially exponentially) many independent instances of a smaller, base oracle. However, showing
quantum indistinguishability between two such keyed oracles can be tricky, since a single query made by an adversary may involve a superposition that covers all instances of the base oracles simultaneously. In this paper, we establish a generic indistinguishability lifting
theorem of the following form: if the two base oracles are indistinguishable under
quantum queries, then their corresponding keyed oracles are too, up to an O(q^2) multiplicative loss in distinguishing advantage, where q is the number of queries made by the adversary. Our lifting
theorem applies to both statistical and computational settings, and to oracles that are stateful as well. It is also optimal in that it matches the obvious Grover search attack for a certain (contrived) choice of oracles. As an immediate application, we extend Carolan's compressed permutation oracle to an efficiently implementable compressed ideal cipher, and use it to prove preimage resistance of the Davies-Meyer compression function in the
quantum ideal cipher model. Thanks to our lifting
theorem, the soundness of our compressed ideal cipher reduces to that of Carolan's oracle, and any further improvement on the latter would automatically carry over to the former. As our second application, we give a modular construction that doubles the message length of any
quantum-secure strong pseudorandom permutation. Along the way, we show that an existing two-round tweakable Feistel construction is indistinguishable from a random permutation under
quantum bidirectional queries. This is done via a dedicated
polynomial-method argument, which may be of independent interest.
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Solar and Stellar Astrophysics
Measured energy exchange in coronal hole solar wind from its solar origins to the heliosphere
Yeimy J. Rivera, Alin R. Paraschiv, Samuel T. Badman et al. (+33 more)
Coordinated ground- and space-based remote observations are used to provide a comprehensive, multi-perspective view of the
solar atmosphere that we connect with in situ measurements in the heliosphere centered around the April 8 2024 Total
Solar Eclipse observed across North America. These near-contemporaneous, multi-wavelength
datasets are used to directly derive the
plasma parameters and compute an energy budget of a
solar wind stream at its low-coronal birthplace (at an altitude of 1.05Rsun). The energy budget is also independently computed at and beyond the Alfvén surface from the in situ observations of the same stream. The total wave energy flux dominates the low-coronal budget (11 W m-2 Alfvén, 7 to 23 W m-2 in compressive MHD modes), while enthalpy (13 W m-2) and work done against
gravity from 1.0Rsun (2.5 W m-2) make up the remainder. The total coronal energy budget is consistent with the total measured in situ by Parker
Solar Probe if and only if compressive energy flux is included and attributed to the fast magnetosonic mode. Nearly all this thermal and wave energy is converted to ion heating, acceleration and gravitational potential energy within the Alfvén surface. The stream
evolution is well-described as a thermal-pressure driven wind with additional energy deposited by MHD fluctuations. The observed
evolution of the Alfvénic component of these fluctuations follows a near-dissipation-free curve below the Alfvén surface while deviating from it more strongly above this critical surface.
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All authors Yeimy J. Rivera, Alin R. Paraschiv, Samuel T. Badman, Alberto M. Vasquez, Federico A. Nuevo, Ryan J. French, Momchil Molnar, Roberto Susino, Zihao Yang, Marco Romoli, Richard A. Frazin, Michael L. Stevens, Stuart D. Bale, Deborah Baker, Jasper Halekas, Thomas A. Schad, Christopher J. Owen, Philippe Louarn, Jenna Samra, Giuliana de Toma, Daniela A. Lacatus, Giulio Del Zanna, Chad A. Madsen, Enrico Landi, Manolis K. Georgoulis, Amir Caspi, Éric Buchlin, Nour E. Raouafi, Luca Franci, Miho Janvier, Cooper Downs, Roberto Livi, Phyllis Whittlesey, Ali Rahmati, Davin Larson, Nikos Sioulas
Quantum Physics
Quantum-State Oblivious Transfer over Quantum Erasure Channels
Remi A. Chou
We study
quantum-state oblivious transfer over the
quantum erasure channel under information-theoretic security guarantees. Specifically, Alice holds two
quantum systems, Bob wishes to recover one of them, and the parties have access to independent channel uses and authenticated public classical communication, with no initial shared
entanglement. We consider both honest-but-curious and malicious behavior. We establish finite-blocklength converse and achievability bounds, which match in the honest-but-curious setting. The malicious setting construction combines interactive hashing with tests of whether Bob received selected channel outputs, and distributes each input across several
qubits so that erasures conceal an entire input from a dishonest receiver, even when the inputs are entangled with an external reference. We also derive fixed-error asymptotic expansions and show that both malicious and honest-but-curious settings have the same capacity.
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Quantum Physics
Correlations decide a shallow-circuit advantage
Zijian Gong, Zhaobin Lyu, Jingjing Hu et al. (+2 more)
Quantum computers are claimed to produce samples ordinary classical computers cannot reproduce. The sharpest such claim known pits constant-depth
quantum circuits, given one entangled state per run, against shallow classical
circuits of few-input gates and limited randomness. No efficient test was known that certifies such a claim from classical samples alone. Here we show that what such a test must read is decided by the classical class's pattern of single-bit and pair correlations, not by a distance. The test rests on one inequality: any machine producing the samples sits no further from the target than the fraction it mislabels plus the deviation of its string half, the bits beyond the label, from uniform. A collapse
theorem, machine-checked in the Lean~4 proof assistant, confines that second term, one setting of the sampler's random input bits at a time. Four natural checks provably fail; a fifth, reading those same correlations, catches a far-from-target construction they cannot reach, and is exact on the class of few-input gates. The label test is proven and sample-optimal in its own tolerance up to a logarithmic factor; the fifth check is sound, not only effective, on the bounded pinned-residue class, pairwise-uniform samplers whose residue, the string's weight modulo the
prime, is pinned by few seeds and whose seed sharing is bounded. What binds an experiment is the $43$-
qubit entangled resource state at fidelity near $0.99$, not the readout. What remains are two named open problems; a positive answer to the first would extend the guarantee to the full class.
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All authors Zijian Gong, Zhaobin Lyu, Jingjing Hu, Dengfeng Li, Shuoming An
Lattice Field Theory · Cross-listed from cs.AI
Efficient Neural Surrogates for Linear Radiation Transport on the Lattice and Hohlraum benchmarks
Carmelo Gonzales, Steffen Schotthöfer and Cory D. Hauck
Linear radiation transport equations (RTEs) form the simulation foundations underpinning design and analysis tasks in
nuclear engineering, inertial confinement fusion, medical imaging, and astrophysics, but resolving the high-dimensional phase space at engineering fidelity remains expensive enough that outer-loop workflows, such as design optimization, uncertainty quantification, and parameter sweeps, are routinely budget-bound on traditional solvers. Neural surrogates promise to relax this bottleneck by amortizing simulation cost across thousands of downstream queries, but the architectural choices and engineered inductive biases that make a surrogate accurate on one transport problem do not transfer straightforwardly across model families. We
benchmark two parameter-matched neural surrogate architectures, the physics-
attention Transolver and the multi-scale graph network Bi-Stride Multi-Scale MeshGraphNet (BSMS-MGN), as end-to-end approximations of the final-time particle concentration for the two-dimensional linear RTE on the canonical
Lattice and Hohlraum
benchmarks. An ablation across
Fourier features and region-weighted training loss exposes strongly architecture-dependent inductive-bias preferences, indicating that design choices common to physics-informed surrogate workflows must be revisited per architecture rather than imported across model families, and that downstream utility depends on per-QoI sensitivity rather than a single field-level score. The model training recipe, training data, and evaluation pipeline are released alongside this paper to support reproduction, transfer to related transport problems, and evaluation as amortized forward-model components in larger outer-loop simulation workflows.
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Strongly Correlated Electrons
Does a pole in the self-energy imply a violation of the Luttinger theorem?
Artem Abanov and Andrey Chubukov
Luttinger
theorem relates
Fermi surface volume to electron density per
spin $n$. It holds in an arbitrary
Fermi liquid but is widely believed to break when a fermionic self-energy has a pole. We show that this is not necessarily the case. As an example, we consider a fermionic system consisting of two gapped bands, originating from a self-energy $\Sigma (\omega, \mathbf{k})$ with a pole, and a narrow residual quasiparticle band crossing $\omega =0$, with a small residue $Z \ll 1$ (a residual
Fermi liquid). We consider Model I, in which $Z$ also renormalizes quasiparticle bandwidth $W$ to $ZW$ and Model II, in which $W$ remains unrenormalized. The Green's function for such a system $G(\omega, \mathbf{k})$ contains two zeros and three poles — one from the quasiparticle band and two from the gapped bands. Yet, we show that in Model I, the Luttinger-Ward analysis is fully applicable for any $Z >0$, and the results are exactly the same as if the gapped bands did not exist. For Model II, the Luttinger-Ward analysis recovers once $Z$ exceeds some critical value, which depends on fermionic density.
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Instrumentation and Methods for Astrophysics
Xenia: A Table-Driven Code for Astrophysical Multi-Fluid Hydrodynamics
Lei Xing
Models of escaping planetary atmospheres require neutral and ion species with distinct velocities and thermal pressures, coupled by photoionization, recombination, radiation, and collisions. Implementing and extending such coupled models is often hindered when species definitions and stiff interactions are embedded in solver-specific kernels. We present Xenia, a table-driven code for astrophysical multi-fluid hydrodynamics designed to lower this barrier. Species, coupling channels, chemistry, heating and cooling, and radiation channels are declared in Python, compiled to symbolic tapes, and passed through a versioned interface to shared C/Kokkos kernels; changing a problem therefore changes data rather than kernel code. For ionized configurations, electrons provide a pressure-only quasi-neutral closure: electron density follows from ion populations, electron mass and momentum are not advanced, and only electron pressure is transported. Stiff coupling is treated by operator splitting into a radial radiation scan,
hyperbolic transport, and a
cell-local implicit source solve. The same symbolic tapes yield an analytic finite-difference-free Jacobian for a direct dense LU solve. The public v0.1 release is validated with acoustic convergence, dustybox drag relaxation, conservation and closure contracts, two-fluid cloud-shock coupling, curvilinear geometry bookkeeping, three escape chains, and 394 passing tests. Conservation and positivity are not claimed to match mature production codes; radiation uses a radial Beer-Lambert prefix product rather than a general solver; escape chains are reproducibility checks rather than new science predictions; and backend evidence is limited to functional deployment and equivalence fingerprints. Xenia is released under GPLv2 at https://github.com/YFG-tec/xenia.
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Strongly Correlated Electrons
Determining the j-Specific Unoccupied 5f Electronic Structure in Actinides
J. G. Tobin
An empirical comparison of high resolution M4,5 X-ray Absorption Spectroscopy (XAS), based upon High Energy Resolution Fluorescence Detection (HERFD), with Bremsstrahlung Isochromat Spectroscopy (BIS), the high energy variant of Inverse Photoelectron Spectroscopy (IPES), of various actinide materials is presented here. It will be shown that XAS-HERFD is essentially the j-specific version of BIS, providing a direct measure of the separate 5f5/2 and 5f7/2 Unoccupied Density of States (UDOS).
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Optics
Phase-matching in high-order harmonic generation with a plasma-reshaped driving field
Gaspard Beaufort, Venus Poulain, Melvin Redon et al. (+13 more)
The transition from titanium-sapphire to ytterbium-based
laser technology enables turnkey implementations of high-order harmonic generation (HHG) setups at high repetition rates, opening up new applications, e.g., in
semiconductor metrology. This, however, requires exploring and understanding the impact of new experimental conditions. Here, we study HHG in neon over the spectral range 8-17 nm with high spectral resolution, using a post-compressed ytterbium
laser. Our measurements reveal a large pulse-energy- and pressure-dependent spectral shift, spanning more than two harmonic orders. The femto-chirp of the harmonic emission combined with the blueshift of the fundamental field allows us to relate the observed spectral shifts to the temporal window of harmonic generation, which is determined by phase-matching. To understand these dynamics, it is essential to consider the reshaping of the driving
laser field inside the
plasma, despite the low driving intensity and long pulse duration. We introduce an on-axis phase-matching description that captures these effects and reproduces the experimental and simulated trends. These results demonstrate the central role of
plasma-induced
laser reshaping in phase-matching of HHG, which should be accounted for when optimizing sources in a multi-parameter landscape.
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All authors Gaspard Beaufort, Venus Poulain, Melvin Redon, Robin Weissenbilder, Elisa Appi, Filip Salbrink, Saga Westerberg, Aimee J. Ross, Sylvianne Roscam Abbing, David P. O'Dwyer, Yin Tao, Per Eng-Johnsson, Cord L. Arnold, Anne L'Huillier, Peter Smorenburg, Anne-Lise Viotti
Mathematical Physics
Dynamical quasi-symmetry of the classical Kepler-Coulomb problem and the conservation of the Laplace-Runge-Lenz vector
Radosław Szmytkowski
The paper studies a classical non-relativistic particle moving in $\mathbb{R}^{N}$, $(N\geqslant2)$, in the presence of the Kepler-Coulomb force $\boldsymbol{F}(\boldsymbol{r})=\alpha\boldsymbol{r}/r^{3}$, $(\alpha\neq0)$. It is shown that the extended-configuration-space transformation involving the projective transformation of the radius vector $\boldsymbol{r}\to\boldsymbol{R}=\boldsymbol{r}/(1+\boldsymbol{c}\cdot\boldsymbol{r})$ and the differential time scaling $\mathrm{d}t\to\mathrm{d}T=\mathrm{d}t/(1+\boldsymbol{c}\cdot\boldsymbol{r})^{2}$, where $\boldsymbol{c}$ is a real vector-valued parameter with dimensions of inverse length, constitutes a dynamical quasi-
symmetry in the sense that it maps Newton's equation of motion $m(\mathrm{d}^{2}\boldsymbol{r}/\mathrm{d}t^{2})=\alpha\boldsymbol{r}/r^{3}$ into the equation $m(\mathrm{d}^{2}\boldsymbol{R}/\mathrm{d}T^{2})=(\alpha\boldsymbol{R}/R^{3}) \operatorname{sgn}(1-\boldsymbol{c}\cdot\boldsymbol{R})$. This quasi-
symmetry is independent of, yet complementary to, the well-known Kepler-Coulomb dynamical
symmetry, which is SO($N+1$) for negative energies and SO($N,1$) for positive energies. A detailed analytical and graphical analysis of induced mappings between non-degenerate conic trajectories associated with the original and transformed systems is presented. Mappings between velocity hodographs are also briefly discussed. It is then proved that the conservation of energy in the transformed motion implies the conservation of the Laplace-Runge-Lenz vector in the original dynamics.
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Quantum Physics
Bounding Two-Way Average Communication Cost of Simulating Quantum Correlations
Kai-Siang Chen, Gelo Noel M. Tabia, Bo-An Tsai et al. (+2 more)
Bell nonlocal correlations cannot be reproduced by local hidden-variable models without communication, making classical communication cost a natural quantitative measure of nonlocality. Although finite communication always suffices to simulate any correlation in a fixed finite Bell scenario, determining the minimum amount needed to (exactly) simulate any given nonlocal correlation remains challenging, especially in the average-cost setting. Here, we derive lower bounds on input-average communication cost from nonlocal games, allowing variable-length, fully interactive two-way protocols. When applied to parallel games, these bounds yield explicit finite
quantum correlations for which the exact simulation cost exceeds any prescribed finite input-average communication budget. For $n$ parallel Magic-Square-winning correlations, we prove a lower bound of $n\log_2(3/2)$ bits and give a one-way communication protocol that attains this rate asymptotically. For the
quantum correlation maximally winning the $n$-copy of the Clauser–Horne–Shimony–Holt nonlocal game, we obtain an input-average lower bound of approximately $0.04627n$ bits for exact simulation. Finally, we formulate a hierarchy of lower bounds and complementary upper bounds using deterministic correlations up to chosen communication costs. Both recover the exact input-average cost at their final levels, and if the bounds agree at lower levels, their common value yields the exact input-average cost without needing to consider all communication strategies.
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All authors Kai-Siang Chen, Gelo Noel M. Tabia, Bo-An Tsai, Swati Kumari, Yeong-Cherng Liang
Chaotic Dynamics
Influence of astrocyte feedback and noise on breathing neural clusters
Ediline L.F. Nguessap, Thierry Njougouo and Fernando F. Ferreira
Astrocytes are increasingly recognized as active regulators of neural dynamics, yet their role in large-scale synchronization remains incompletely understood. Building on the discovery of breathing cluster synchronization in
neuron-astrocyte networks, we investigate whether this phenomenon persists under more biologically realistic conditions by incorporating thermosensitive neuronal dynamics, intrinsic electric-field interactions,
stochastic perturbations, and delayed astrocytic feedback. Through systematic numerical simulations of a network containing structurally symmetric neuronal subsets, we show that breathing clusters characterized by intermittent alternations between synchronized and desynchronized states, remain robust across a broad range of biophysical conditions. The results reveal a non-monotonic dependence on astrocytic attenuation and feedback parameters, with intermediate values maximizing rhythmic switching through a slow push-pull regulatory mechanism. Temperature and electric-field effects primarily modulate neuronal excitability and the tolerance of the breathing state to noise, while elevated
stochastic perturbations progressively destabilize cluster coherence. In contrast, the phenomenon exhibits remarkable robustness to biologically realistic astrocytic delays. Importantly, our findings indicate that the emergence of breathing synchronization remains fundamentally governed by the interplay between network
symmetry and astrocyte-mediated feedback, whereas temperature, electric fields, and noise act as modulators of its stability and temporal organization. These results establish breathing cluster synchronization as a robust organizing principle of astrocyte-regulated networks and provide a quantitative framework for understanding how glial regulation shapes cortical state-switching under realistic physiological conditions.
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Solar and Stellar Astrophysics
Global solar compressible convection simulations on non-Cartesian mappings
Grégoire Doebele, Allan Sacha Brun and Maxime Delorme
Context. Modeling the global dynamics of the Sun requires numerical frameworks capable of simulating the highly turbulent convective envelope and its coupling with the stable radiative interior. Simulating such spherical domains in standard cartesian finite-volume codes presents significant topological challenges. Aims. The goal is to extend the cartesian Adaptive Mesh Refinement (AMR) framework Dyablo to non-cartesian geometries in order to perform global
solar convection simulations that extend all the way down to the
stellar core. Methods. We introduced a mapped grid approach within the Dyablo framework to build Dyablo Whole Sun (DWS) code. We implemented an $\alpha-\beta$ well-balanced scheme to preserve hydrostatic
equilibrium. Furthermore, we present a robust methodology to generate fully integrated
solar background profiles from $r=0$ to the surface. Results. We validated the implementation using standard hydrodynamic tests and ran high-resolution 2D global
solar convection simulations on a disk grid. Conclusions. Our models successfully capture the turbulent convective broad slow upflows and narrow fast downflows and the excitation of acoustic waves and p modes. The interaction of strong downflowing plumes with the top of the radiative zone, successfully excites internal
gravity waves in the radiative interior.
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Mathematical Physics
Covariant Euler-Poincaré Reduction for Field Theories on Centered Semidirect Products
Miguel Ángel Berbel, Leonardo Colombo and Álvaro Rodríguez Abella
Let $G$ be a Lie group equipped with commuting left and right linear representations on a vector space $V$, and let $G\Join V$ be the associated centered semidirect product. We develop a reduction scheme for covariant field theories on principal bundles with structure group $G\Join V$ from both Lagrangian and
Hamiltonian perspectives, obtaining the reduced Euler-Poincaré and Lie-Poisson field equations decomposed into their $\mathfrak g$- and $V$-components, where $\mathfrak g$ is the Lie
algebra of $G$. We also derive the reduced multisymplectic form formula, as well as the Noether and energy-momentum balance laws. Our reduction results are compared with those for principal bundles with standard semidirect-product structure groups, and the role of the centered variables is investigated: they retain the original two-sided
geometric data and separate the left and right contributions via the heart and diamond operators. The framework is then applied to a two-sided
matrix microstructural model and to the second-order jet group on $\mathbb R^r$, $G_r^2$. For the
matrix model, the conjugation representation decomposes $\operatorname{Mat}(3)$ into scalar, vector, and symmetric-traceless sectors, clarifying its precise relation to director and
alignment-tensor variables without identifying it with standard nematodynamics. For the one-dimensional jet group on a $(1+1)$-dimensional Minkowski base, we obtain a semilinear symmetric-
hyperbolic system and an exact traveling conversion front with explicit energy-momentum exchange between the linear- and quadratic-jet sectors. Its
hyperbolic-target interpretation yields a conserved positive energy for the linearized perturbations. A nonlinear numerical experiment illustrates the reduced
evolution and reconstruction of the group-valued field, with consistency assessed through mesh refinement and an independent wave-map computation.
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Instrumentation and Methods for Astrophysics
Vector field dark matter search with Sagnac interferometer
Yuki Inoue, Quynh Lan Nguyen and Ippei Obata
We present the first calculation showing that a material-asymmetric Sagnac speed meter can improve
quantum-noise-limited sensitivity to $B-L$ vector dark matter by nearly two orders of magnitude over a Fabry–Perot Michelson position meter at the low-mass end of the band. We introduce material contrast into a dual-ring interferometer to probe composition-dependent $B-L$ forces and compare the two configurations at equal incident power, input-mirror transmissivity, and cavity round-trip length. For sapphire mirrors and a one-week
benchmark, the
quantum-noise-only median expected $95\%$ CL upper limit reaches $1.2\times10^{-27}$ at $m_A=4.1\times10^{-14}\,\mathrm{eV}/c^2$ ($10\,\mathrm{Hz}$), a factor-$57$ improvement. This band-edge forecast assumes negligible classical noise; sensitivity at $10\,\mathrm{Hz}$ is not established for a realizable suspension and isolation system. The material-induced displacement is essentially identical in both configurations, with the gain arising from reduced low-frequency
quantum backaction. These results identify speed-meter readout as a promising route to lower-mass vector-dark-matter searches.
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Quantum Physics
Exact Clifford Optimality for Two-Sided Locally Randomized Classical Shadows
Xiaotian Nie, Tao Zhang, Yadong Wu et al. (+1 more)
Entangling measurements can reduce the statistical cost of learning many-body correlations. We study Pauli strings with full support on a specified $k$-
qubit region using classical shadows with two independent, uniformly random product single-
qubit Clifford layers around a controllable
unitary acting on that region, followed by computational-basis readout. In this architecture, we prove that a
circuit $U_*$ of two collective Pauli rotations attains the exact minimum squared shadow norm over all Clifford choices of the controllable
unitary for every $k\geq1$, namely $C_k^{\rm opt}=4\cdot 9^k/(3\cdot 5^k+3^k-6)$ for odd $k$ and $C_k^{\rm opt}=4\cdot 9^k/(3\cdot 5^k-3^k+2)$ for even $k$. The asymptotic optimum $(4/3)\cdot(9/5)^k$ establishes Wu et al.'s exponential base as optimal and improves their prefactor from $2$ to $4/3$. For $1\leq k\leq6$, exact rational certificates prove that the same optimum holds over the entire
unitary group $\mathrm U(2^k)$, including all non-Clifford
unitaries, within the same measurement architecture. These finite-size results motivate the
conjecture that $U_*$ is optimal over all
unitaries for arbitrary $k$ within this architecture.
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All authors Xiaotian Nie, Tao Zhang, Yadong Wu, Linghui Chen
Statistical Mechanics
MUTACO: Simulator-Efficient Response Matching in Stochastic Nonlinear Systems via Compatibility-Aware Sequential Design
Ege Karadeniz, İlter Onat Korkmaz, Umut Can Turhan et al. (+2 more)
Many physical inverse problems are mediated by expensive
stochastic simulators for which response gradients, adjoint sensitivities, or a differentiable simulator interface are unavailable. We introduce Multiple Target-based Confident Acquisition (MUTACO), an uncertainty-aware sequential-design method for response matching that requires only noisy forward evaluations and learns the multicomponent response together with its predictive uncertainty. We develop and evaluate MUTACO for a disordered network of
stochastic phase oscillators. The inverse task is to infer statistical properties of the local potential and interactions from macroscopic rotation and synchronization curves under multiple driving conditions. Rather than requiring unique recovery of these statistical properties, MUTACO searches for parameter configurations whose predicted rotation and synchronization responses are compatible with the target response while accounting for predictive uncertainty. This response-centered formulation is appropriate when experimentally accessible observables characterize ensemble statistics rather than a particular microscopic realization. Under strictly limited simulation budgets, MUTACO achieves the lowest held-out response error among the tested adaptive-search, space-filling, and simulation-based inference methods, while also yielding lower parameter-recovery error than the compared methods. These results demonstrate that response-targeted sequential design is a simulator-efficient approach to inverse modeling from finite noisy forward evaluations and suggest broader applicability to
stochastic physical systems with correlated multicomponent responses and weakly constrained parameter directions.
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All authors Ege Karadeniz, İlter Onat Korkmaz, Umut Can Turhan, Cem Tekin, Ayd{\i}n Cem Keser
Mesoscale and Nanoscale Physics
Spatiotemporal imaging of microwave magnetic fields via magnonic coherent splitting
C. K. Wei, Z. J. Chen, J. T. Song et al. (+7 more)
Spatiotemporal microwave
magnetic-field imaging reveals current flow in high-frequency
circuits and nonequilibrium
spin dynamics, yet probes rarely combine calibrated spectral readout, optics-free operation and transient mapping at room temperature. Here ferrimagnetic order in yttrium iron garnet supports coherent coupling from a pump-induced
magnon mode, converting target-field amplitude into a spectral splitting with all-microwave readout. Sampling the calibrated splitting over position and delay reconstructs spatiotemporal imaging of
magnetic fields. Continuous-wave measurement reaches a sensitivity of 58 pT/$\sqrt{\mathrm{Hz}}$ and recovers phases across various powers. Combined with time-resolved frequency-comb spectroscopy, the method reconstructs transient fields with a 130-ns response time. Coplanar-waveguide imaging validates the
magnetic selectivity of the mode-splitting readout, where measured maps agree with simulated
magnetic-field distribution. In a microwave amplifier, our reconstruction resolves nonuniform switching dynamics and detects downstream field suppression from an open-contact fault. Magnonic coherent splitting provides a scalable route for optics-free imaging of spatiotemporal field
evolution in functional devices.
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All authors C. K. Wei, Z. J. Chen, J. T. Song, S. H. Ma, W. H. Liu, J. H. Wu, Z. W. Huang, Jinwei Rao, Wei Lu, Bimu Yao
Quantum Physics · Cross-listed from cs.DM
New Methods for Constructing Classical and Quantum Codes from Graphs and Matroids
Anderson S. Barbosa, Franklin de L. Marquezino and Giuliano G. La Guardia
In this paper, we present a method for constructing linear codes derived from book graphs. Applying such a method, we construct binary codes that have the greatest possible minimum distance for their length and dimension by means of the $2$-sum of two equal book graphs. We then utilize matroid and graph theory together to investigate some properties of the resulting linear codes. Furthermore, we show that, from the incidence
matrix of any graph, we can obtain a linear code over any finite field maintaining the same parameters. Furthermore, we show how the condition for two linear codes to generate a Calderbank-Shor-Steane (CSS) code translates into matroid theory and, utilizing cycle graphs, we exhibit a way to generate codes that meet this condition.
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Quantum Physics
Multi-Yoked Surface Codes
Yuga Hirai and Yasunari Suzuki
The surface code is the leading candidate for fault-tolerant
quantum computation owing to its planar nearest-neighbor connectivity, high threshold, and efficient decoding, but its low encoding rate demands on the order of a thousand physical
qubits per logical
qubit in the teraquop regime. Yoked surface codes improve the density by a factor of two or three by concatenating a high-density parity check code on top of the surface code while retaining planar nearest-neighbor connectivity. In this work, we generalize this idea to multiple levels of concatenation and introduce multi-yoked surface codes. Our construction rests on two new ingredients. First, we propose a family of outer codes called chain codes, built by chaining copies of a seed code that detects the block errors of the code one level below; the resulting codes use all logical
qubits of the lower level and achieve a high encoding rate within a few concatenation levels. Second, we design a patch allocation in which movable workspaces perform the yoking checks by
lattice surgery with a hierarchy of yoking intervals, so that lower-level checks are performed frequently while higher-level checks are performed less often, which avoids the long yoking intervals that a single large-distance outer code would require. As a
benchmark, we construct a three-yoked surface code with a $[[256,166,8]]$ outer code and evaluate it numerically under the SI1000 noise model using soft information from the surface code decoder. The logical error rate is suppressed exponentially in the inner code distance, and in the teraquop regime the three-yoked surface code is about 4 to 4.5$\times$ denser than the unyoked surface code.
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Materials Science
Development and Application of a Magnetoelectric Coupling Measurement System for Strain-Mediated Effects
Samanway Mohanta, Poonacha C.T, Hemant Singh et al. (+6 more)
This paper reports about development of a dynamic lock-in based magnetoelectric (ME) coupling measurement system and its application to investigate strain-mediated coupling in 0.65Pb(Mg$_{1/3}$Nb$_{2/3}$)O$_3$-0.35PbTiO$_3$/NiFe$_2$O$_4$ (PMN-PT/NFO) and CoFe$_2$O$_4$/BaTiO$_3$ (CFO/BTO) composites. The PMN-PT/NFO composite exhibits a significantly enhanced ME coefficient ($\alpha_{\mathrm{ME}} \approx 1.85$~mV\,mm$^{-1}$\,Oe$^{-1}$) compared to CFO/BTO ($\approx 0.147$~mV\,mm$^{-1}$\,Oe$^{-1}$). The antisymmetric field dependence and $180^\circ$ phase reversal confirm the strain-driven origin of coupling in both the samples. The superior response of PMN-PT/NFO arises from the combined effect of high piezoelectric strength in PMN-PT and low
magnetic anisotropy of NFO, whereas the high
magnetic anisotropy of CFO and weaker piezoelectricity of BTO limit the ME output. These results highlight the decisive role of
magnetic softness and piezoelectric strength in optimizing strain-mediated ME coupling.
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All authors Samanway Mohanta, Poonacha C.T, Hemant Singh, Gunjan Verma, A. Ahlawat, S.C. Das, G. Sinha, V. G. Sathe, D. K. Shukla
Quantum Physics
Efficient Quantum State Identity Testing
Shih-Han Hung and Ming-Hsien Tsai
We study the following
quantum state identity problem: given access to copies of $n$ unknown pure
quantum states, the goal is to determine whether every pair has fidelity at least $1-\varepsilon$ or some pair has fidelity at most $\varepsilon$. This problem relaxes the identical-or-orthogonal promise considered in previous work. For any fixed overlap parameter $\varepsilon\in(0,1/4)$, we present two
quantum algorithms with complementary guarantees on
circuit depth and sample complexity. The first runs in constant depth using parallel swap tests and takes $O(\log(n/\delta)\log(2/\delta))$ copies of each input state to succeed with probability at least $1-\delta$. The second uses the Schur transform to reduce the sample complexity to $O(\log(n/\delta))$, through an analysis relating Jucys–Murphy elements to Schur sampling. We also prove a matching sample complexity lower bound of $\Omega(\log(n/\delta))$ for any
quantum algorithm with failure probability at most $\delta\le 1/2-c$, for any constant $c>0$, establishing that the second
algorithm achieves the optimal dependence on both $n$ and $\delta$ for fixed $\varepsilon$.
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General Relativity and Quantum Cosmology
Quasinormal-Mode Collider Spectroscopy
Mian Zhu, Jun Tao and Peng Wang
Black-hole (BH) quasinormal modes encode the properties of merger remnants and provide powerful tests of strong-field
gravity. The BH spectroscopy has predominantly treated them as independent linear oscillations. Nonlinear ringdown can additionally reveal how these modes interact and which intermediate states mediate their interactions. Inspired by cosmological
collider physics, we introduce quasinormal-mode
collider spectroscopy (QCS), a framework for organizing and predicting nonlinear BH responses. We establish two structural results. First, at an isolated, nondegenerate intermediate pole, a cubic strain residue factorizes into an excitation amplitude and a quadratic conversion coefficient. This factorization imposes rank constraints across output channels and choices of second-order initial data, providing consistency tests of the intermediate-mode description. Second, the intermediate pole residue can be reconstructed from its horizon and infinity radiation. With the first-order field and third-order data held fixed, this reconstruction extends to the full cubic waveform difference generated by changing the second-order initial data. QCS thus connects lower-order radiation to higher-order observables and provides a framework for probing the interaction structure of nonlinear ringdown.
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Solar and Stellar Astrophysics
SWAN-SF-V2: A Multivariate Time Series Dataset for Space Weather Data Analytics; Now with AIA and Weighted SHARP Parameters
Dustin Kempton, Griffin Goodwin, Reet Gupta et al. (+4 more)
Since its original publication in 2020, the SWAN-SF
dataset has been cited in over 300 research publications. Here we describe a comprehensive update to the original multivariate time series (MVTS)
dataset extracted from
solar photospheric vector magnetograms in the Spaceweather HMI Active Region Patch (SHARP) series. As was performed in the original release, our
dataset includes a cross-checked NOAA
solar flare catalog that facilitates the comparative evaluation of methods designed for
solar flare prediction. We discuss the methods used for data collection, cleaning, and pre-processing of the
solar active region and
flare data, which includes improvements to the data integration and sampling methodology. Additional parameters have been derived from the
Solar Dynamics Observatory's Atmospheric Imaging Assembly to augment the original features derived from magnetogram data. Our
dataset expands the period of observations to cover 7,730 MVTS data collections from active regions occurring between May 2010 and December 2025, each of which is composed of 182
flare-predictive parameters. We continue to integrate
flare reports, with over 39,000 multi-source verified
flare reports providing flaring history information about the source active regions. The primary tasks enabled by the disseminated
dataset continue to include optimization of
solar flare prediction and detailed investigation for elusive
flare predictors or precursors, with both operational (research-to-operations), and basic research (operations-to-research) benefits.
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All authors Dustin Kempton, Griffin Goodwin, Reet Gupta, Viacheslav M Sadykov, Rafal A. Angryk, Berkay Aydin, Manolis K. Georgoulis
Quantum Physics
Variational Quantum Attention for Molecular Graph Learning
Yu-Cheng Lin, Yu-Chao Hsu, Tai-Yue Li et al. (+2 more)
Molecular property prediction is central to computational drug discovery, where graph neural networks learn to weight neighboring atomic environments during message passing. Yet it remains unclear how variational
quantum circuits alter learned
attention behavior in molecular graphs. We introduce an edge-aware variational
quantum attention mechanism for molecular graph learning, in which the receiving atom, neighboring atom, and connecting bond jointly determine the
quantum attention state. Across five molecular property and bioactivity prediction tasks, QGAT achieves competitive performance relative to GATv2, with a consistent improvement on BBBP across all six evaluated
circuit ansatzes. We further compare how the
quantum and classical
attention scores weight molecular structure beyond accuracy. In the Verubecestat BACE1 inhibitor series, QGAT achieves a higher Spearman correlation than GATv2 and assigns positive attributions to several structural changes consistent with reported structure-activity relationships (SARs). This case study shows that the two
attention mechanisms can exhibit different prediction and attribution behavior across structurally related BACE1 analogues, while broader validation is required to determine how consistently these differences generalize across chemical series and targets.
Circuit ablations further show that performance depends on the
circuit design. Together, these results show that variational
quantum attention can serve as a viable alternative molecular
attention parameterization while inducing
circuit- and chemistry-dependent behavior distinct from a matched classical scorer.
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All authors Yu-Cheng Lin, Yu-Chao Hsu, Tai-Yue Li, Nan-Yow Chen, Samuel Yen-Chi Chen
High Energy Astrophysical Phenomena
Revisiting damping of Alfvén waves in partially ionized plasmas
Yutaka Ohira
We investigate the damping rate of Alfvén waves by means of the linear analysis of the two-fluid ten-moments system. To treat effects of viscosity in a wide frequency range, we take account of the time
evolution of the traceless part of the pressure tensor. In addition, to treat effects of viscosity in a wide range of the ionization degree, we consider interactions between hydrogen atoms and between
protons and hydrogen atoms in the equation of the traceless part of the pressure tensor. We find approximate analytical solutions to the dispersion relation for some limits. Our analysis in the low-frequency limit shows that the viscous damping dominates over the frictional damping in the high-beta
plasma, which is independent of the ionization degree. Therefore, the viscosity of hydrogen gas significantly affects
cosmic-ray propagation in a partially ionized high-beta
plasma.
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Mesoscale and Nanoscale Physics
Micromagnet engineering for enhanced addressability of donor-cluster arrays in silicon
Hao Wang, Baolong Zhao, Shihang Zhang et al. (+11 more)
Phosphorus donors in silicon are one of the promising platforms for fault-tolerant
quantum computing, owing to their long coherence times and compatibility with complementary metal-
oxide-
semiconductor (CMOS) technology. However, a key bottleneck for scaling this platform lies in the independent addressability of individual
spin qubits. Here, we present a scalable
quantum processor architecture that integrates scanning tunneling microscope (STM)-defined phosphorus donor-cluster arrays with on-chip micromagnets. By generating
magnetic field gradients, the micromagnets enable a broader addressable frequency range compared to the addressing scheme based solely on variations in hyperfine (HF) interactions, which arise from the randomness of intra-cluster configurations. Through micromagnetic simulations to optimize micromagnet geometry, we demonstrate that these structures are compatible with customized array designs, facilitating the integration of over 120 atomic
spin qubits and enabling frequency multiplexing with a single microwave
antenna, which greatly reduces the overhead of fan-out addressing lines. This design is further validated via
magnetic measurements, which generally align with our micromagnetic simulations. These results establish a critical foundation for the development of scalable silicon
quantum computing with atomic
qubits.
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All authors Hao Wang, Baolong Zhao, Shihang Zhang, Ziliang Jin, Huan Shu, Peihao Huang, Guanyong Wang, Mingchao Duan, Tianluo Pan, Tao Xin, Guangchong Hu, Zhen Tian, Dapeng Yu, Yu He
Quantum Physics
Decoy-state optical quantum information processing with coherent states
Wenyuan Wang and H. F. Chau
Photonic
qubits play an important role in
quantum information processing. However, to date, efficient high-speed single
photon sources and
photon number resolving (PNR) detectors are still difficult to make. Here, we use phase-randomized coherent states and threshold detectors, combined with decoy-state post-processing, to simulate single
photon sources and PNR detectors and perform various
quantum information processing tasks. We propose a simple linear regression method to predict Fock state statistics based on observable statistics from coherent-state probes, combined with random/structured sampling of probe settings. Compared with traditional decoy-state post-processing based on linear programming and Cartesian product grid sampling, our method enables drastically improved accuracy and much reduced probe resources. It works particularly well for unknown
unitary circuits of interest with fixed-size
Hilbert space dimensions. For instance, it can accurately simulate 4-
photon interference in linear optics with just 32 input/output probe settings and 6-
photon interference with 256 probe settings. Moreover, it also works for non-
unitary (such as lossy, nonlinear, or arbitrary)
quantum channels. This enables a wide variety of applications that can be implemented with easily attainable coherent light sources and threshold detectors, such as characterization of small-scale linear optical
quantum computing
circuits or
quantum sensing/metrology devices.
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General Relativity and Quantum Cosmology
Dynamic Quantum Wormholes: Path-Integral State Selection and the Quantum Throat Trajectory in an Exactly Solvable Thin-Shell Model
Rikpratik Sengupta and Paulo Vargas Moniz
We construct a minisuperspace quantization of a dynamic, spherically symmetric thin-shell wormhole in the spirit of pilot-wave
quantum cosmology, treating the throat radius $a(\tau)$ as the single degree of freedom of the Israel junction-condition constraint. For a pressureless shell of mass $M$ the Wheeler–DeWitt equation reduces exactly to Whittaker's equation, and to the modified Bessel equation as $M\to0$. When the exterior is asymptotically flat, boundedness of the wave function as $a\to\infty$ selects a unique state that can always be chosen real. Since any real solution has a vanishing Bohmian current, the throat is frozen for any linear equation of state and any operator ordering, independently of the choice between Euclidean and Lorentzian boundary conditions. This state is the exact $\epsilon\to0^+$ limit of the regularized Lorentzian path integral, as shown by resolvent analyticity and by an exact Picard–Lefschetz thimble calculation that agrees with the closed-form solution to $48$ digits. The near-throat self-adjointness ambiguity is resolved in closed form through the Whittaker connection formula. Replacing the exterior by Schwarzschild–de~Sitter removes the obstruction: the potential tends to $-\infty$ at large $a$, and the equation admits a genuinely dynamic, purely outgoing state. Propagated exactly through the classically forbidden barrier, it carries a conserved, nonzero Bohmian current everywhere, including the inner pocket. It describes a long-lived metastable wormhole that tunnels into unbounded expansion at a rate consistent with the WKB estimate. Airy connection formulas leave a residual prefactor constant $\kappa_\infty=0.814\pm0.004$ for sub-critical coupling, which we do not trace to its analytic origin, and the physical results do not depend on it.
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Computational Physics
Spectral properties of the Riemann zeta function and their physical applications
Kostadin G Gaminchev
This work studies the Riemann $\zeta$ numerically with emphasis on its physical manifestations. Three areas are examined: (i) the spectral statistics of the non-trivial zeros, which we compare with the Gaussian
Unitary Ensemble predictions, obtaining $\chi^2/\text{dof} = 1.2$; (ii) the role of $\zeta(\frac{3}{2})$ in determining the critical temperature for Bose-Einstein condensation, where we find $T_c = 0.13$ K for an ideal gas; and (iii) the application of $\zeta$-function regularisation to the Casimir effect, yielding the standard Casimir energy density $-\frac{\pi^2 \hbar c}{720 a^3}$, which for $a=1\,\mathrm{nm}$ gives $\sim -4.33\times10^{-4}\,\mathrm{J\,m^{-2}}$. The numerical results are consistent with the Montgomery-Odlyzko
conjecture and with spectral approaches motivated by the
Hilbert-Pólya
conjecture, within the statistical limitations of the analysis.
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