Papers

The discovery of superconductivity in nickelates has seeded a new field for exploring unconventional superconductivity in transition metal oxides. However, to date superconductivity has only been realized in thin films or under extreme pressure in the bulk. Here we report signatures of superconductivity at ambient pressure in bulk nickelate single crystals of (La1-xPrx)4Ni3O8 and (La1-xYx)4Ni3O8, whose crystal structure comprises interleaving trilayers of square-planar nickel oxide and fluorite-like spacer layers. The parent compound La4Ni3O8 exhibits an insulating ground state, where electrons order into intertwined, insulating charge/spin stripes. Substitution of smaller lanthanide ions disrupts this order, eventually leading to a metallic ground-state. We find that superconductivity emerges in a narrow window proximate to the insulator-metal phase boundary, where both metallic and charge-stripe phases co-exist. The observed low volume-fraction superconductivity is non-percolative, suggesting the prospect of filamentary superconductivity nucleated at the boundary between these phases. However, intergrowth defects that approximate the known infinite layer nickelates are observed in TEM, leaving open the possibility that superconductivity resides here rather than in the trilayer matrix. Remarkably, the electronic phase diagrams of both the Y and Pr series coincide when parameterized by the volume of the fluorite like spacer layers, revealing that this steric parameter profoundly modifies the nickel oxide trilayer electronic structure. Our results identify better understanding of the co-existence region between metallic and charge-ordered phases as a priority for expanding the range of bulk, ambient-pressure nickelate superconductivity and establish spacer-layer engineering as a design tool for exploring this regime of phase competition.

Three-dimensional fine-grained plastic scintillator detectors are extensively used in high-energy physics experiments where particle tracking, identification, calorimetry and sub-nanosecond timing information are required. Moreover, the low cost of plastic scintillator makes, in principle, the scalability to multi-tonne detectors possible. In order to circumvent the difficulties related to the long production time and the challenging assembly of millions of tiny independent scintillating voxels, a new technology consisting of gluing a few thousand $9 \times 9 \times 9$ mm$^3$ plastic scintillator cubes in a single large monolithic layer with machining precision, while ensuring an efficient optical separation, was developed and demonstrated. In this work we demonstrate that such technology can be reliably extended to a monolithic layer of $48 \times 48$ optically-isolated scintillating cubes, the size required for future ton-scale detectors, fulfilling the requirements of future neutrino detectors and sampling calorimeters.

Large deviation theory lacks a geometric foundation for its rate functions and fluctuation symmetries. This paper develops a contact large deviation theory on stochastic vector bundles, in which the rate function, the scaled cumulant generating function, and a Gallavotti–Cohen-type fluctuation duality all follow from the contact 1-form. The constraint function acts as a generalized Lagrangian; the least constraint principle yields the dynamics, and the contact potential is built order by order from the master equation, producing a coupled Hamilton–Jacobi–transport system governed by the invariant density, drift, and fluctuation tensor. The contact path measure satisfies a large deviation principle with rate function given by the constraint action; the scaled cumulant generating function obeys a stationary eigenvalue equation with a Donsker–Varadhan variational characterization. The entropy production rate, the fluctuation–dissipation combination $e=\tfrac12 g^T Ag-\sigma$, is the physical observable; the time-reversal involution $J:(t,y,\phi)\mapsto(t,y,-\phi-\nabla\ln\rho)$ with reversed drift $v^{\mathrm{rev}}=-v+Ag$ yields a Gallavotti–Cohen-type duality $\lambda_{\mathrm{fwd}}(q)=\lambda_{\mathrm{rev}}(q+1)+\lambda_{\mathrm{fwd}}(-1)$. The classical one-dimensional GC symmetry is recovered in the reversible case $Ag=0$.

The symmetry of the superconducting gap is related to the symmetry of the crystal structure. In unconventional superconductors, big changes of the critical temperature, critical field or even the gap structure can happen even for small perturbations of the lattice. In this letter, we use microstructuring to study aluminium-free crystals of UBe$_{13}$ which are expected to be closer to "perfect" material than previously studied aluminium-grown single crystals. We compare the effect of minuscule imperfections on the value of the critical temperature and critical field, which, in the case of UBe$_{13}$, has drastic effects, supporting its unconventional nature. We conjecture that this likely arises from the oxidation state of uranium, which is sensitive to its crystal environment. Our findings suggests that uranium-based materials provide not only an excellent reservoir of new unconventional phenomena, but also a way to identify the gap symmetry of unconventional superconductors.

Quantum linear systems algorithms (QLSAs) aim to solve linear systems $A\bb{x}=\bb{b}$ exponentially faster than classical methods under certain conditions. In this work, we develop quantum algorithms for solving linear algebraic equations from an ODE-based perspective. Inspired by the linear combination of Hamiltonian simulation (LCHS) representation in the Fourier approach \cite{Childs2017QLSA}, we express the solution $\bb{x}$ as a linear combination of solutions to a system of linear convection equations, which become Schrödinger-type equations with unitary evolutions in the Fourier domain. We refer to this representation as LC-Schrödingerization. Based on this result, we construct an LCHS-based quantum algorithm with two LCHS instances: one for time-marching and one for numerical integration. The key construction uses the derivative of a Gaussian-smoothed hat function and recovers the solution over a fixed auxiliary interval. This permits a truncation time independent of the target accuracy and avoids the loss in success probability from selecting a single grid point. Periodization and explicit Fourier coefficients provide the corresponding projection error bounds. Under the stated oracle assumptions and given a constant-factor estimate of the solution norm, direct simulation of the select operators and block preconditioning achieve the optimal matrix-query complexity $\mathcal{O}(\kappa_A\log\frac1\varepsilon)$ without using variable-time amplitude amplification (VTAA). The same upper bound holds for queries to the right-hand-side preparation oracle.

We examine the impact of gamma-ray line and direct-detection searches on neutralino dark matter in supersymmetric SU(5) with non-universal gaugino masses. Under the assumption that neutralinos constitute all halo dark matter, a nearly pure wino benchmark at 1 TeV is essentially excluded by the H.E.S.S. line limits for both cusped and cored density profiles. Higgsino and wino-Higgsino benchmarks are independently excluded by direct detection. In contrast, a bino benchmark near thermal saturation combines suppressed present-day line emission with scattering below the displayed experimental limits. Mixed bino-wino solutions illustrate the complementarity of the two searches and the dependence of the line interpretation on the Galactic halo profile. We relate these results to the GUT-scale gaugino hierarchy and the SU(5) scalar and Higgs boundary conditions. Thermally underabundant solutions require additional production to realize the full-density assumption. Comparing the calculated signals with published electroweakino predictions, we identify the spectrum-dependent corrections and collider tests needed to determine the surviving parameter space.

The long-standing upward shift of the extracted $\psi(4160)$ mass, from about $4.16$~GeV to $4.19$~GeV in later analyses, remains a puzzling issue in charmonium spectroscopy. In our previous study, this problem was investigated through the $B^+\to K^+\mu^+\mu^-$ process within an unquenched charmonium framework, where the lower-mass $\psi(4160)$ assignment was found to be compatible with the data. Here we revisit the BESII $R$-value data, which played an important role in the historical extraction of the higher $\psi(4160)$ mass, and provide an independent examination. In contrast to the conventional quenched picture with $\psi(4040)$, $\psi(4160)$, and $\psi(4415)$, the unquenched vector-charmonium spectrum contains six states: $\psi(4040)$, $\psi(4160)$, $\psi(4220)$, $\psi(4380)$, $\psi(4415)$, and $\psi(4500)$. Including these states together with the near-threshold $\psi(3770)$, we find that the BESII $R$-value line shape can be well reproduced over the full energy range while retaining the lower-mass $\psi(4160)$ assignment. The enhancement around $4.19$~GeV then arises from the coherent interplay among the nearby $\psi(4040)$, $\psi(4160)$, and $\psi(4220)$ amplitudes, rather than requiring an upward shift of the $\psi(4160)$ mass itself. The additional higher states also naturally describe the line-shape structure in the $4.4$~GeV region. We further show that the seven-resonance coherent amplitude contains six complex zeros, yielding $2^6=64$ mathematically equivalent solutions with identical line shapes but substantially different di-electron widths and relative phases. Comparing these solutions with available experimental information and representative unquenched charmonium predictions, we provide a qualitative assessment of their phenomenological consistency and highlight several solutions that appear more compatible with present information.

Cross-correlation is crucial in studies of multiwavelength flux variability in active galactic nuclei (AGNs), especially for reverberation mapping analysis, where interpolated cross-correlation function is widely used to measure time lags between light curves. While time-lag uncertainties can be estimated via the flux randomization and random subset selection method, an appropriate framework for assessing cross-correlation significance remains lacking in the literature. Here we attempt to fill this gap by leveraging the well-established property from stochastic time series theory, namely that the probability distribution of cross-correlation coefficients for independent stochastic light curves asymptotically approaches a normal distribution. Its variance can be analytically estimated using the auto-correlation functions of the light curves. We employ Monte Carlo simulations to validate this property for irregularly sampled, red-noise AGN light curves, and then propose a fast procedure to perform null-hypothesis testing for the cross-correlation of AGN light curves. We also present exemplary applications to AGN reverberation mapping data. This procedure requires prior determination of the auto-correlation functions of light curves, which can be obtained via model fitting. The long-standing issue regarding unbiasedly recovering the auto-correlation function remains unresolved when light-curve duration is comparable to the typical variation timescale, warranting further future investigation.

The impact dynamics of hollow droplets, while influential in applications such as coating and spraying, remain less explored than their dense counterparts. In particular, the impact dynamics of viscoelastic hollow droplets have yet to be fully explored. This study presents an experimental investigation into the impact of hollow Newtonian (water) and viscoelastic (polymeric solution) droplets on a solid surface at different impact velocities and polymer concentrations. We demonstrate two hallmark features of hollow droplet flattening: the formation of a central counter-jet and the final deposition, both associated with the entrapped air bubble. For Newtonian droplets, the counter-jet exhibits rapid growth and breakup due to capillary instabilities. Introducing polymer additives fundamentally alters this behavior: viscoelasticity affects the counter-jet's height and velocity, delays bubble rupture, and inhibits droplet detachment. Crucially, we observe the emergence of beads-on-a-string structures during filament thinning, a signature of the competition between elastic and capillary forces. By systematically varying the polymer concentration and impact velocity, we identify the conditions under which three distinct outcomes occur: deposition, partial deposition, and detachment. Our results show how inertia, viscosity, capillarity, and elasticity together govern the splashing morphology of hollow non-Newtonian droplets.

Design of high-contrast freeform reflectors is challenging, as the presence of zero-intensity regions leads to degeneracy in the associated Monge-Ampere-type equation. A common remedy is to add a positive artificial background to the target intensity, which improves the regularity of the equation. However, this regularization inevitably reduces the achievable illumination contrast and introduces nonzero intensity into regions that are intended to remain dark. We propose a fast c-transform method based on optimal transport duality for high-contrast freeform reflector design in the far field without artificial background regularization. The method integrates repeated discrete c-transforms into a measure-based dual optimization scheme to maintain the c-concavity of the reflector potential throughout the iteration. This preserves the admissibility of the iterates and enables stable convergence for targets with zero-intensity regions. To efficiently compute the discrete c-transforms, we develop a localized search algorithm that exploits their contact structure and prove its exactness and linear complexity. Numerical experiments demonstrate that the proposed method accurately realizes high-contrast illumination targets with zero background.

Experimental particle physics collaborations staff their detectors around the clock with members drawn from dozens of institutions. The established practice is a credit system with self-sign-up: institutions owe a quota of credit, and people take the seats they want when booking opens. This paper describes a method in which seats are instead allocated from ranked wishes under institutional quotas, the result is issued as offers that each person accepts or declines, and an independent checker recomputes every rule before anything is published: the platform proposes, never assigns, and proves that it kept the rules. The credit and quota model is inherited from current practice. Around that core the paper adds a quota rule that keeps indivisible blocks fair to institutions whose share of a period is smaller than one block, and four rules that make fairness visible beyond the count: shares of owl, weekend and holiday blocks, seats shown in the laboratory's clock and the institution's own, reachable pools for institutions that cannot travel, and booking order by balance. On a synthetic collaboration of 48 institutions and 256 eligible members, the method allocates 70 to 72 of 72 seats per period in two rounds, with a mean rank satisfaction of 84 to 95% and no rule broken; after a year of running every institution of four members or more is within 13% of its cumulative share, and the smallest institutions, which one block overshoots by arithmetic, are brought within the same range by pooling in pairs. The method is stated completely enough to be reimplemented; a reference implementation exists and is available to collaborations under license. It applies as it stands to any scientific collaboration that staffs a facility in blocks of shifts under institutional quotas.

Star clusters with ages of a few Myr have a previously unexplained dispersion in the lithium equivalent widths. In this work, we show that much of the lithium spread of the young cluster NGC 2264 can be attributed to the observational presence of starspots. We demonstrate that the equivalent width of Li I 6708 Angstrom changes with observed spot coverage, using a sample of 15 Weak-Lined T Tauri Stars (WTTSs) with multi-epoch high-resolution ESPaDOnS spectra and photometry. To quantify the contribution of starspots, we construct an empirical two-component starspot model. When differences in visible spot coverage are taken into account, 68% of the WTTSs fall within the model-predicted EW(Li) dispersion for a range from 0-90% visible spot coverage. We find no correlation between the age spread or gravity and Li I equivalent width in NGC 2264. Our results suggest that invoking starspots can explain much of the apparent lithium spread in NGC 2264 and reduces but does not fully eliminate the need to invoke rotation-driven lithium depletion or other non-standard explanations at such young ages. Future simultaneous measurements of lithium and beryllium in young stars may provide an independent test of this scenario.

While two-photon exchange (TPE) effects in space-like nucleon electromagnetic form factors have been extensively studied for over two decades, their manifestations in the time-like region have yet to be definitively established. We propose the isospin-violating decay $J/\psi \to \bar{\Sigma}^{0}\Lambda$ and its charge-conjugate process as a sensitive probe of TPE contributions to time-like hyperon electromagnetic form factors. This channel provides a clean laboratory for isolating TPE effects through sensitive and robust polarization and spin-correlation observables, which are particularly enhanced by the $\Lambda$-$\Sigma^0$ mass splitting. Combining a dispersion-relation analysis of the one-photon-exchange contribution with explicit loop calculations of the TPE amplitudes, we perform a quantitative study of TPE effects in the threshold region. Our results demonstrate that the considered observables can provide unambiguous signatures of TPE contributions and present predictions for their size together with the associated theoretical uncertainties.

A neural turbulence closure defines a new boundary-value problem, $R(U)=N(U)+F(U)=0$, with a coupled Jacobian $J(U)=N'(U)+F'(U)$, where $N$ is the original mean-flow operator and $F$ the learned closure. We establish two consequences of global tangent dissipation. For a monotone original operator, a positive uniform margin supplied by the original operator and closure together guarantees existence, uniqueness and a global inverse-sensitivity bound relating a posteriori solution error to the a priori residual. For a general original operator, a dissipative closure cannot worsen tangent dissipation, but this alone does not guarantee uniqueness. Tangent dissipation depends on both diffusion and reaction. We study two complementary ways to promote it: (1) an exact-integral construction enforcing non-negative tangent diffusion while leaving reaction unconstrained, and (2) a penalty on tangent-reaction violations at sampled states. Tangent diffusion enters the Jacobian, and non-negative secant eddy viscosity alone does not control its coercivity. We conduct tests with channel flow at $Re_\tau=180$–$5200$, which provides a strongly monotone baseline. Both constrained closures reach accurate solutions in all 50 training-seed/Reynolds-number cases. At $Re_\tau=1000$, we conduct tests with 10,000 starts for one fixed network per closure and we find one root for each constrained closure and multiple roots for the other closures. Although this does not prove uniqueness, it provides strong empirical evidence for uniqueness of the tested constrained closures. At $Re_\tau=5200$, the construction and penalty reduce the reported inverse sensitivity relative to the original operator by approximately $372\times$ and $11\times$, respectively.

Nucleation rates are exponentially sensitive to the thermodynamic driving force and can therefore depend strongly on the treatment of long-range intermolecular interactions. Here, using the Lennard–Jones (LJ) system as a benchmark, we combine molecular dynamics (MD) simulations, jumpy forward-flux sampling (jFFS), and free-energy calculations to quantify the effect of potential truncation on melting thermodynamics, homogeneous crystal nucleation kinetics, and computational cost. Within the cutoff-radius range $2.5\sigma\le r_c\le 6\sigma$, the melting temperature at zero pressure varies by approximately 11%, while the nucleation rate changes by approximately ten orders of magnitude. By invoking classical nucleation theory (CNT), we show that this pronounced kinetic sensitivity originates primarily from cutoff-induced changes in the chemical potential difference between the liquid and crystalline phases. Building on this observation, we develop a CNT-based framework for extrapolating finite-cutoff rates to the full-potential limit and for estimating the expected rate deviations at other cutoff radii and temperatures. These findings also provide a systematic basis for cutoff selection: the optimal cutoff should minimize computational cost while keeping the deviation from the full-potential rate within acceptable bounds. At $kT/\epsilon=0.5$, $r_c=4\sigma$ provides a reasonable compromise according to these criteria. We further demonstrate that conventional homogeneous tail corrections do not offer a reliable alternative, as they cannot consistently account for the liquid, crystalline, and interfacial environments present during nucleation. Our findings highlight the need to specify and validate the truncation scheme as an integral component of force-field development in simulations of nucleation and other interfacial phase transitions within inhomogeneous environments.

Crustal strength is often characterized using a strength-depth profile where laboratory-derived friction and flow laws are connected at depth (i.e., the so-called Christmas Tree diagram). Large, destructive earthquakes frequently nucleate within the transition zone from a frictional-to-viscous deformation regime, which represents the strongest part of the crust. However, microscale deformation mechanisms controlling bulk frictional-to-viscous transitional behavior remain unclear. To investigate the deformation mechanisms, we conducted shear experiments on room-dry, powdered quartz-albite mixtures under upper- to mid-crustal pressure-temperature conditions using a Griggs-type deformation apparatus. We simulated depth conditions in the range 7-30 km, by varying temperatures and confining pressures (210-900 C and 185-870 MPa, respectively, by assuming 30 C/km and 2,700 kg/m3). To assess the rate dependence and stability of shear deformation, we sequentially stepped shear strain rates between 10^-3/s and 10^-4/s. At shallower depth conditions, friction coefficients follow Byerlee's law, while at greater depth conditions they deviate from it and strain weakening is observed. Post-mortem microstructures indicate changing deformation mechanisms with increasing simulated depths. The samples deformed at shallower depth conditions (<18 km) show a predominance of cataclastic grain comminution. At greater depth conditions (>24 km), nano-grains are observed, as well as polygonal quartz grains at the greatest depth condition (30 km). These results indicate that the controlling deformation mechanisms at the frictional-viscous transition zone are grain boundary sliding and dynamic recrystallization. We conclude that nano-scale deformation mechanisms govern the frictional-viscous transitional deformation in the upper crust, and propose their importance for understanding seismic rupture processes there.

We present a unified analytical treatment of carrier transport relaxation in bilayer graphene (BLG), including scattering by surface roughness, charged and neutral impurities, acoustic and optical phonons, and substrate polar phonons. The calculation is formulated within the low-energy two-band approximation using Fermi's golden rule and the semiclassical Boltzmann transport equation. Closed-form expressions for the transport relaxation rates are derived and verified by numerical evaluation of the corresponding scattering integrals. Particular attention is given to Pauli blocking, whose influence becomes important under degenerate carrier conditions owing to the approximately parabolic low-energy dispersion and nearly constant density of states of BLG. We find that Pauli blocking modifies the relaxation rates in a mechanism- and energy-dependent manner for both suspended and substrate-supported BLG. For the parameters considered, neutral-impurity scattering provides the dominant contribution over a substantial energy range, while acoustic-phonon and charged-impurity scattering remain important competing mechanisms. Optical-phonon scattering is suppressed below its emission threshold, whereas substrate polar phonons provide an additional relaxation channel in supported BLG. Comparison with monolayer graphene and a conventional two-dimensional electron gas highlights the role of band dispersion, density of states, screening, and chirality in determining the distinct scattering behavior of BLG. These results provide analytical insight into the relative importance of the principal momentum-relaxation mechanisms and the role of Pauli blocking in BLG transport.

Peptide-HLA binding prediction is a critical step in neoantigen identification for personalized cancer immunotherapy and holds significant clinical value. However, the training data available for many HLA alleles are extremely limited, which severely constrains the performance of conventional methods on this task. Parameterized quantum circuits are hypothesized to induce inductive biases beneficial for learning from small datasets, yet their application to biological sequence prediction remains underexplored. To address this, we propose a hybrid quantum-classical neural network (HQNN) specifically designed for peptide-HLA binding prediction. HQNN integrates multi-source biological feature encoding with parallel quantum feature extractors and a quantum-enhanced classifier. On two HLA alleles (A*02:01 and B*07:02), HQNN outperforms a parameter-matched classical CNN baseline across all training sizes, with the performance gap widening as training data decreases. Ablation studies confirm the respective contributions of the quantum feature extraction module and the quantum classifier. In noise-aware simulations, performance degrades only mildly, and such degradation is reasonable and acceptable under realistic quantum hardware noise levels. These results suggest that hybrid quantum-classical architectures can provide practical sample-efficiency gains for immunoinformatics tasks in low-data regimes.

Quantum computers are technologically novel and unusual, but at system scale they should be engineered using many of the same principles that govern classical heterogeneous accelerators. This paper argues that utility-scale quantum architecture is primarily a cost-performance problem across a coupled quantum-classical system, leading to a blueprint for scalable quantum processing unit (QPU) design. Our architecture blueprint is organized around clean logical abstractions, hiding details and complexity of physical qubit modalities below the instruction set architecture (ISA) boundary, and specializes recurring functions aggressively to minimize the cost for utility scale quantum computations. Its low-level implementation through specialized local hardware for control, readout, and quantum error correction (QEC) closely resembles the architecture of high-performance network stacks. One of our main insights is that the design principles and the resulting architecture closely follow established practice from classical computing and networking.

Broken symmetry and topology are distinct descriptions for how matter organizes itself. Here, we propose one gives rise to the other. A mixed singlet-triplet $d$-density wave, which is a particle-hole condensate, has a hidden bond order that breaks translation symmetry and generates a time-reversed pair of Chern bands, without producing conventional charge or spin density order. At fractional fillings with odd denominators, finite size exact diagonalization studies show how repulsive interactions can transform this symmetry-broken topological state into a fractional quantum spin Hall liquid. Its opposite chiralities produce a crossed response in which charge flux transports spin, and spin flux transports charge. The same setting also reveals what borders such a phase. Strong interspin coupling and increasingly dilute fillings favor charge order and make residual band dispersion decisive, while at half filling, the spin-decoupled limit gives a homogeneous correlated liquid with signatures consistent with the physics of a composite Fermi liquid.

Photomultiplier tubes (PMTs) are widely used in imaging atmospheric Cherenkov telescopes. Their response can depend on the telescope pointing direction through changes in their orientation relative to the geomagnetic field. Such a dependence was indicated during the calibration campaign of the CTAO LST-1. In this work, the LST-1 calibration data are analyzed to quantify the gain dependence in terms of the geomagnetic field, and dedicated laboratory measurements are performed to test the hypothesis that the observed dependence originates from magnetic-field effects. Both the on-site and laboratory measurements show a consistent dependence of the PMT gain on the magnetic field, while the laboratory measurements further separate the effects on the gain and the excess noise factor. These results provide a clearer understanding of the gain variation observed in LST-1 in terms of magnetic-field effects.

Symmetry plays a fundamental role in modern physics by guiding the classification of phases and the construction of effective theories of critical systems. Identifying collective symmetry remains challenging because tests based on preselected order parameters can overlook hidden components. A central goal is therefore to extract symmetry and critical information from a single accessible component. We pursue this goal using Lee–Yang zero ratios generated by a single ordering field. Unmeasured components shape the projected fluctuation distribution and hence the relative zero positions. Deep in a phase with spontaneous symmetry breaking, we show analytically that the zero ratios for an isotropic order parameter approach a parameter-free Bessel sequence fixed by the number of collective components. Near quantum criticality, fluctuations deform this distribution. The resulting ratio deviations and their finite-size coupling dependence carry additional critical information. We demonstrate these results with large-scale quantum Monte Carlo simulations of many-body systems with conventional and enlarged continuous symmetries. This approach provides quantitative access to collective symmetry and criticality without measuring every competing order.

Electrostatic modulation of graphene provides a tunable route to engineering miniband structures. We perform quantum transport simulations on a gate-defined graphene superlattice junction, formed by confining a two-dimensional superlattice graphene (SGr) region between two normal graphene (NGr) regions. In the low-field regime at low carrier densities, robust Fabry-Pérot interference fringes emerge even in the unipolar regime due to Fermi-velocity renormalization in the SGr region. At stronger magnetic fields but only up to 3 T, the conductance map clearly reveals the Hofstadter butterfly spectrum. At intermediate fields, our finite-width transport simulations reveal a new type of snake state, the supersnake state, composed of alternating anomalous cyclotron arcs on the SGr side and conventional semicircular arcs on the NGr side, forming a weaving trajectory along the junction. The resulting conductance oscillations agree well with geometrical conditions derived from semiclassical cyclotron orbits. Our results demonstrate that gate-defined NGr-SGr-NGr junctions provide a versatile platform hosting multiple transport regimes within a single device architecture and can be generalized to other types of superlattices not restricted to graphene.

Quantum imaginarity is a distinct resource in quantum information theory, yet its nonlocal properties have not been fully explored. Here, we report an experimental study of the nonlocal advantage of quantum imaginarity (NAQI), in which local measurements on one subsystem can steer the average imaginarity of the conditional states of the other subsystem beyond the corresponding classical bound. The $l_1$-norm of imaginarity inequality is adopted as an experimentally accessible witness. A hybrid optimization algorithm that combines a genetic algorithm with sequential quadratic programming is developed to avoid local optima and accelerate the search for optimal measurement settings. Using polarization-encoded photonic qubits, we prepare two classes of two-qubit Bell-diagonal states and experimentally characterize the imaginarity of the conditional states following local measurements. Clear violations of the $l_1$-norm of imaginarity inequality are observed, providing an experimental certification of NAQI. We further investigate the relationship among NAQI, the nonlocal advantage of quantum coherence (NAQC), and Bell nonlocality based on their respective inequality criteria. For the two-qubit Werner states considered in this work, the regions of states that violate the respective criteria satisfy $\mathcal{D}_{\rm NAQC}\subset\mathcal{D}_{\rm NAQI}\subset\mathcal{D}_{\rm BN}$. Our work provides an experimental realization of NAQI and a comparison of different forms of quantum nonclassicality in a photonic platform.

Characterization, control, and calibration of stringiness, the propensity to form long, thin, persistent threads, are key to the design and application of polymer solutions and formulations transferred to substrates by dropwise dispensing, jetting, spraying, or coating, and are used in manufacturing fibers, membranes, or spray-dried products. For Newtonian fluids, enhancing shear viscosity translates into increasing stringiness as can be easily perceived during dripping of water vs. sugar syrups or glycerol-water mixtures. In contrast, even polymer solutions with comparable shear viscosity can display a significant contrast in extensional rheology and apparent stringiness. However, there are no quantitative maps, formulas, or scales for stringiness, which motivates this study. In this contribution, we contrast the stringiness for a series of aqueous polymer solutions by determining the filament lifespan using dripping-onto-substrate (DoS) rheometry and filament length and lifespan in using dripping-into-air (DiA). We investigate the influence of polymer chemistry and molecular weight on stringiness and rely on DoS rheometry to characterize pinching dynamics and extensional rheology response. We show that an increase in stringiness correlates with steady, terminal extensional viscosity, and extensional relaxation time, respectively. Lastly, we provide a framework, which compares the stringiness of different polymer solutions through an extensional Ohnesorge-Deborah ($Oh-De$) plot or $Oh_E-De_E$ map, by computing the two dimensionless groups $Oh_E$ using steady, terminal extensional viscosity and $De_E$ using extensional relaxation time, respectively

GeoAI increasingly produces reusable Earth representation s, physical forecasts, multimodal systems, and reasoning a gents. Their progress exposes two distinct limitations. Geo graphic completeness asks whether the represented world ex tends beyond readily observed land surfaces and atmospher ic fields to oceans, biogeography, economies, institutions, and human agency. Geographic intelligence asks whether model outputs preserve place, scale, relations, process, un certainty, and the limits of valid inference. The first con cerns what exists in a model; the second concerns what may responsibly be claimed about it. This critical integrative review argues that geography provides the organizing gram mar that connects these dimensions. Seven structural gaps, propositions, and corresponding review questions translate the argument into testable requirements. The resulting re search agenda advances Living Geospatial Models as federat ed, continually updated systems that couple specialist Earth and human-domain models through shared geographic iden tity, support, relations, provenance, and uncertainty. The objective is not a single universal network, but geospatial intelligence that can explain connections and change, antic ipate plausible futures, and support accountable decisions across places and scales.

Higher twists in deep-inelastic scattering (DIS) and related hard scattering processes provide a unique window on nonperturbative QCD dynamics, encoding quark-gluon correlations and multiparton interactions beyond the leading-twist parton model. We present an overview of the theoretical foundations of higher twists in QCD, based on the operator product expansion, and discuss their intimate connection with quark-hadron duality in the transition between the resonance and scaling regimes. We review the phenomenology of higher-twist effects in unpolarized and polarized DIS, emphasizing their extraction from precision data through modern global QCD analyses that simultaneously determine both leading-twist parton distribution functions and higher-twist contributions. Finally, we discuss recent developments in the study of higher twists in semi-inclusive and exclusive reactions, and conclude by highlighting future opportunities to study QCD dynamics beyond leading twist at Jefferson Lab and the Electron-Ion Collider that promise to deepen our understanding of hadron structure.

We construct a restricted Boltzmann machine (RBM) whose visible input is a quantum state rather than a classical configuration. Each hidden unit carries a trainable quantum template prepared by a parametrized circuit and converts its overlap with the input into a feature. Treating quantum states as high-dimensional continuous visible objects creates nontrivial normalization and scaling problems. We regularize the continuous likelihood and derive two controlled high-dimensional limits, yielding a Hopfield-type network with continuous Hilbert-space patterns and a data-augmented Gram likelihood. The resulting algorithms are compact and use trainable circuit-prepared templates as measurement intermediaries between quantum data and classical optimization. Numerical simulations across several many-body systems demonstrate effective quantum-phase recognition and multicomponent feature extraction.

Multicomponent order can melt in stages, leaving a composite order after its primary constituents become short ranged. We study this possibility for commensurate three-$Q$ loop-current order on the kagome lattice. Large-scale cluster and parallel-tempering Monte Carlo simulations reveal direct and two-stage melting regimes in an effective fixed-amplitude sign model. In the latter regime, translation-sector domain walls proliferate before chirality-changing walls, restoring lattice translational symmetry while preserving long-range time-reversal-odd order. The primary $M$-point correlations are short ranged in this intermediate phase. The two-stage regime begins when the lowest-energy chirality-changing wall is only about $12$–$13\%$ more costly than a same-chirality translation wall. Finite-size scaling of a stable amplitude-resolved Ginzburg–Landau theory shows that the phase survives amplitude relaxation. Our results establish a quantitative domain-wall criterion for vestigial loop-current order and a fluctuation route to time-reversal symmetry breaking without long-range loop-current Bragg order. This separation provides a possible thermodynamic framework for time-reversal-odd responses recently reported above the critical temperature for conventional charge-density-wave ordering in kagome metals.

The coercivity of rare-earth permanent magnets originates from the crystal field acting on localized 4f electrons, yet how grain boundaries modify the underlying single-ion Hamiltonian remains largely unknown. Here we determine the 4f crystal field in bulk and grain-boundary environments of Nd2Fe14B using embedded multireference electronic-structure calculations for the substitutional series Ce, Pr, Nd, Gd, Tb, and Dy. Grain-boundary distortion produces a crossover across the lanthanide series: the crystal field weakens by up to 36% for light lanthanides but strengthens by about 25% for heavy lanthanides, with Nd marking the crossover. The ground-state doublet of Dy becomes more isolated and axial, whereas Ce exhibits a collapsed low-lying excitation that suppresses anisotropy. The local easy axis rotates from the bulk c axis toward the basal plane, identifying grain-boundary sites as favorable nucleation centers for magnetization reversal. These results provide an atomistic basis for heavy rare-earth grain-boundary diffusion and furnish transferable single-ion parameters for spin-lattice simulations.