Papers

We construct the Carrollian limit of the Cortés–Plyushchay wave equations for planar anyons, grading the spin-tower components by powers of $c$ and taking the limit at fixed rest energy. The result is a linear system describing Carrollian particles of any real spin — Carrollian anyons — and, at (half-)integer spin, Carrollian bosons, fermions and higher-spin fields. The system is a first-order square root of the standard Carroll wave equation $(\partial_t^2+E^2)\Phi=0$, whose spectrum consists of two flat branches at plus and minus the rest energy. Scaling the spin along with $c$, in the Carrollian analogue of the Jackiw–Nair limit, yields instead the exotic Carroll algebra, with a second central charge, non-commuting boosts, and observable coordinates spanning a noncommutative plane. We show how the Galilean and Carrollian theories branch from one common similarity transformation: the Galilean limit expels the negative-energy modes, whereas the Carroll limit retains both relativistic branches.

Game theory studies strategic decision-making among rational agents, and many classical games can be mapped onto interaction models such as the Ising model. Quantum game theory extends this framework by allowing players to exploit quantum superposition and entanglement. In this work, we study quantum games using an operator-based formulation derived from the transverse-field quantum Ising model. We show that the Hamiltonian-driven dynamics naturally generate entangling operator which resolve the dilemma in the game settings. This leads to a clear quantum advantage over classical outcomes. Unlike standard quantization schemes based on fixed entangling gates, the present approach enables tunable entanglement, controlled directly by physical Hamiltonian parameters, providing a hardware-relevant perspective on quantum game design.

We study the topological structure of the quantum phase diagram of gapped systems by identifying the noncontractibility of loops, so-called $S^1$-families, within the gapped phase diagram in which many-body Hamiltonians can have nontrivial ground-state degeneracy. We manifest the role of symmetries in such $S^1$-family classifications by the exotic symmetry interplay: (i) nontrivial mixed anomalies, (ii) semi-direct product relation between the spontaneously broken and the unbroken symmetries, and (iii) symmetry with noninvertible operators. We find that such structures lead to the novel $S^1$-family classifications inaccessible by earlier classifications based on “independent” symmetries. Furthermore, we construct lattice realizations of these $S^1$-families and explicitly demonstrate their novel algebraic structures.

Entanglement-based networks provide a scalable framework for multiuser quantum communication by passively routing spectrally correlated photon pairs across interconnected nodes. Several wavelength-allocation schemes have already been demonstrated experimentally, but these designs do not yet provide a general way to determine how spectral use, receiver load, repeated connections, fan-out, and optical loss constrain one another. Motivated by a field-deployed four-node network, we formulate wavelength assignment as an exact resource-optimization problem on the network connectivity graph. We consider uniquely paired wavelength channels and require that no user receive both channels of a pair. For one-sided fan-out, we obtain an exact optimization for arbitrary networks, and closed-form resource laws for complete networks and for networks with one excluded partner per user. Allowing both conjugate wavelengths to fan out changes the resource landscape. In complete networks, a balanced binary hierarchy uses the minimum number of spectral layers among nonredundant assignments while reducing the maximum receiver wavelength load to a quantity that grows logarithmically with the number of users. For eight users, the source-cost ordering depends on splitter transmission: changing the transmission can change which architecture requires less pair generation. We formulate a BBM92 rate model for evaluating the corresponding architectures. For a single continuous-wave broadband source, the occupied wavelength pairs are generated with fixed relative weights, while detector singles and accidental coincidences couple the link rates. The same resource laws can therefore be evaluated using the measured parameters of the hardware that implements the network.

Future wireless systems are expected to transform the surrounding space from a passive propagation medium into a smart electromagnetic environment, where engineered surfaces control wave propagation, support wireless sensing, and create programmable electromagnetic fingerprints. A key challenge in realizing this vision is the inverse design of metasurfaces for tailored electromagnetic propagation. While forward analysis evaluates the response of a known geometry, the inverse task starts from a prescribed scattering signature and seeks a physically realizable structure that produces it. This inverse task is inherently nonlinear and often high-dimensional, while candidate solutions may be non-unique and provide no direct indication of practical realizability. Here, we introduce a conditional diffusion framework for inverse design of dielectric resonator metasurfaces from target angular scattering patterns. Trained on T-matrix simulated geometry-response pairs, the model learns a conditional distribution of geometries instead of a deterministic mapping, enabling multiple candidate designs for the ill-posed inverse problem. The best generated metasurface achieves a mean percentage error of 1.39%, outperforming CMA-ES optimization (4.1% after 10 h) while requiring only about one minute for after-training inference. The model also produces lower error distributions than deterministic neural baselines for out-of-distribution spectra, highlighting the potential of diffusion models for efficient metasurface design.

Several next-generation fission reactor designs employ molten salts such as FLiBe (2LiF-BeF$_2$), with some concepts using fuel dissolved directly in the salt. During operation, fission products such as cesium will accumulate in the salt mixture, potentially leading to an evolution of the thermophysical properties underpinned by the atomic structure. To understand the structural perturbations in FLiBe with 5 mol% CsF, we conducted X-ray and neutron diffraction measurements, refined empirical potential structure refinement (EPSR) models against the experimental data, and compared the resulting structure with neural network molecular dynamics (NNMD) simulations. Comparisons of the EPSR and NNMD structures distinguishes features constrained by the scattering data from those that remain model dependent. The new Cs-bearing correlations account for the changes in the total structure factor and pair-distribution function, while the FLiBe correlations remain minimally altered. We find that Cs slightly disrupts the intermediate-range fluoroberyllate network, increasing the fraction of free fluorine ions, while the local coordination remains largely unchanged. The Cs ions within FLiBe cluster extensively, with BeF$_4^{2-}$ tetrahedra bridging neighboring cesium environments. In contrast to the minor structural perturbations in the liquid, the addition of 5 mol% CsF suppressed the formation of the crystalline Li2BeF4 phase at room temperature, with the phase appearing only above 180C upon heating. These experimentally constrained structural features provide a benchmark for atomistic models used to predict the behavior and properties of fission-product-containing FLiBe.

Kolmogorov-Arnold Networks (KANs), inspired by the Kolmogorov Arnold representation theorem, provide an interpretable alternative to multilayer perceptrons (MLPs) by using learnable activation functions on edges rather than fixed node activations. We propose a Physics-Informed Kolmogorov-Arnold Network (PI-KAN) framework for solving forward problem of viscoelastic fluid equations, which arise in many complex fluid dynamics applications and are characterized by strong nonlinear coupling between fluid fields. For viscoelastic fluid equations, we adopt the generalized hydrodynamic model, which is well established in the field of dusty plasma. To evaluate the performance of the proposed framework for viscoelastic fluid, we consider benchmark problem based on the Taylor-Green (TG) flow and a modified Taylor-Green flow. We systematically investigate the effects of different network architectures, hyperparameters, and collocation point distributions on the accuracy and convergence behavior of PI-KANs for the range of viscoelastic parameter ($\tau_m = 1$–$20$). We also study the impact of random seed initialization on training outcomes. The obtained results provide useful guidance for the design and implementation of physics-informed Kolmogorov-Arnold networks (PI-KANs) in solving viscoelastic fluid equations

To test the potential of so-called quantum physics-informed neural network (QPINN) technology for solving evolutionary partial differential equations, we consider the problem of multiple wave propagation in a weakly nonlinear medium described by the Korteweg-de Vries equation with periodic boundary conditions. Although this problem is solvable analytically, high-genus solutions could represent a rather challenging testbed for numerical methods. Therefore, our idea is to test whether a QPINN is sufficiently mature for application in this context by providing a set of indicators of merit and performing several numerical experiments.

The internal structure of galaxies encodes the complex baryon cycle driven by gas accretion, star formation, and feedback, together with secular evolution and environmentally driven processes such as mergers and tidal interactions. We present a population-level census of massive nearby galaxies ($\log(M_\star/M_\odot) > 10$) by comparing Hyper Suprime-Cam Subaru Strategic Program observations with matched mock images from IllustrisTNG, EAGLE, and SIMBA. Using a consistent, like-for-like imaging pipeline, we construct structural abundance functions (SAFs) for key morphological parameters, revealing a structural abundance crisis. Across Sérsic index, concentration, size, and ellipticity, all simulations exhibit large, systematic discrepancies ($>5\sigma$; RMSE $\sim 0.2$–$1.8$\,dex), typically corresponding to abundance differences of factors of several. While individual simulations display diverse failures—underproducing or overproducing compact spheroids, extended or round galaxies —all underproduce highly flattened disks. Although TNG shows the closest agreement and SIMBA the largest offsets, this shared failure indicates that current models—despite matching global demographics such as the stellar mass function—do not uniquely constrain internal galaxy structure. Our results demonstrate that agreement in integrated observables can mask fundamental shortcomings in the modelling of mass and angular momentum redistribution. We therefore establish SAFs as a stringent, multidimensional, and observationally accessible benchmark for testing and calibrating next-generation galaxy formation models in the era of upcoming deep, wide-field surveys.

On a compact connected section ${\cal S}$ of a supersymmetric $M$-horizon the Killing-spinor bilinears give a pointwise identity relating the warp factor $\Delta$, the rotation one-form $h$ and the two spinor norms, with nothing assumed about the norm of the Killing spinor. We derive three consequences of that unreduced identity. First, a single-point rigidity theorem: if $\Delta$ and $h$ vanish at one point of the section, then the flux vanishes identically, ${\cal S}$ is Ricci-flat and the horizon is $\mathbb{R}^{1,1}\times{\cal S}$. A single point replaces the usual global spinorial hypothesis. Second, the ${\rm Spin}(7)$ decomposition of the flux fixes $h$ algebraically and exhibits the invariant flux content of the scalar square $\Delta=4\Phi^2$ known in an adapted gauge, $\Delta=\frac{1}{108}\|w_{\bf 7}\pm\sigma({\cal Y}_{\bf 7})\|^2$. Only the two ${\bf 7}$-summands $w_{\bf 7}$, ${\cal Y}_{\bf 7}$ reach the warp factor, and the square is degenerate rather than definite: it vanishes on the linear subspace $w_{\bf 7}=\mp\sigma({\cal Y}_{\bf 7})$ rather than at the origin, so positivity of $\Delta$ yields no case list. Third, the two combine into a pointwise budget: the single constant of supersymmetry is shared between the deviation from staticity and the ${\rm Spin}(7)$ mismatch of the flux, each bounded by that constant. The same identities characterise the constancy hypothesis, equivalent to $V=-fh$ for the bilinear one-form $V$, which fails on the static branch of known warped $AdS_2$ solutions; they fix a weighted integral of the warp factor; and they reduce the Komar angular momentum of the horizon to a positive bilinear integral. Two no-go statements, for hidden symmetries built from the Killing spinor and for a second isometry from its bilinears, are stated with their hypotheses.

In the whole space of low spatial dimensions, namely $d \leq 2$, we study the minimizers of an energy functional with an attractive cubic nonlinearity and a repulsive quintic nonlinearity, which describes a quantum Bose gas with a two-body attraction and a three-body repulsion. We prove the existence of minimizers at fixed effective statistics parameter. In the limit of a large effective statistics parameter of the mass-critical nonlinearity (with respect to the kinetic energy), we derive an effective Thomas-Fermi-like model for the homogeneous Bose gas. We also consider other limit regimes depending on the mass-critical nonlinearity.

We consider a homogeneous Bose gas composed of $N$ identical bosons occupying an infinite two-dimensional space. This gas exhibits both an attractive two-body interaction and a repulsive three-body interaction. Via the intermediate Hartree theory, we rigorously derive the homogeneous cubic-quintic nonlinear Schroedinger functional as the mean-field limit of the model. Our investigation focuses on the system's behavior in relation to the two-body interaction.

We investigate the behavior of a homogeneous one-dimensional Bose gas composed of $N$ identical bosons experiencing attractive two-body and repulsive three-body interactions. Utilizing intermediate Hartree theory, we rigorously derive the homogeneous cubic-quintic nonlinear Schrödinger functional as the mean-field limit of the many-body Hamiltonian. Particular attention is given to the impact of the repulsive three-body term on ground state energy estimates and mass concentration properties

Rhombohedral multilayer graphene hosts a distinctive low-energy electronic structure in which strong Coulomb interactions and nontrivial quantum geometry intertwine to generate exotic quantum states. Recent experiments reported signatures of chiral superconductivity in electron-doped rhombohedral multilayer graphene within the spin- and valley-polarized regime. Here we map the normal-state fermiology surrounding chiral superconductivity in rhombohedral pentalayer graphene. Quantum oscillation measurements reveal an electrically controlled Lifshitz transition between a simply-connected circular quarter-metal Fermi surface and an annular quarter-metal Fermi surface. The Lifshitz boundary itself shifts with perpendicular magnetic field, consistent with the strongly momentum-dependent orbital magnetic moment of the low-energy band. Approaching the transition from either side, the electron effective mass becomes strongly enhanced, implying the formation of a nearly dispersionless band bottom and a strongly reduced kinetic-energy scale. This singular electronic structure produces a regime of exceptionally strong instability in which chiral superconductivity competes with Wigner crystalline phases and reentrant quantum Hall states. In particular, two superconducting regions with signatures of orbital time-reversal-symmetry breaking lie on opposite sides of the Lifshitz boundary and have comparable transition temperatures, yet the annular-side state is suppressed by a substantially smaller perpendicular magnetic field. Our calculation finds comparable chiral pairing tendencies on the two parent Fermi surfaces while producing a much lower orbital-Zeeman pair-breaking scale and an additional finite-momentum pairing tendency for the annular state. These results identify Fermi-surface topology as a key control parameter for chiral superconductivity in rhombohedral graphene.

The Virasoro conjecture predicts a set of universal relations among all genera Gromov–Witten invariants of any smooth projective variety. The conjecture is well understood for semisimple theories, but remains largely open in the non-semisimple setting. We prove the genus-one Virasoro conjecture on the ambient state space of smooth Fano complete intersections in projective space. For most of these complete intersections, the big quantum cohomology is nowhere semisimple. We also generalize the wall-crossing formula for quasimap invariants with weighted markings to the equivariant twisted setting, allowing descendant insertions at light markings. Together with genus-one quantum Lefschetz for quasimaps with light markings, this wall-crossing formula provides the key bridge from the Gromov–Witten theory of the complete intersection to the semisimple equivariant twisted theory of the projective space.

Wood slices under a polarized optical microscope show a spectrum of interference colors, such as cyan, blue, magenta, yellow, and bluish gray because of the birefringent cellulose in the microfibrils. An optical model is established to simulate the birefringent-colored micrograph of wood. Five typical cell wall architectures, line, helix, ring, crossed helix, and twisted helix, are considered. With a retardation wave plate to distinguish fibrils of different orientations, each structure displays its unique birefringent-colored texture, presenting its underlying 3D structure with the vivid colors. Cross sections of the trunk and twig of Eucalyptus grandis presented birefringent-colored profiles. Three identification methods were compared: visible fibril trends, birefringent-colored optical textures, and the simulated look-up library. The three methods gave consistent results, proving that the birefringent-color tags are efficient and accurate. Electron and atomic force microscopy are unable to resolve cellulose microfibrils embedded in the lignin and hemicellulose matrix. Polarized optical microscopy overcomes this by selectively detecting birefringent cellulose, enabling accurate identification of complex helical structures. This method enables statistical and spatial analysis of complex biomaterial compositions. Capable of profiling dozens of cells simultaneously, this high-throughput optical method provides a potentially fully automated analysis framework for plant science, biomechanics, and bioinspired cellulose materials.

The inclusive weak radiative $B$-meson decay provides important constraints on many popular extensions of the Standard Model. Some of the numerically relevant Next-to-Next-to-Leading-Order QCD corrections to its branching ratio have so far been evaluated using an interpolation in the charm quark mass between the $m_c=0$ and $m_c \gg m_b$ limits. In the current paper, we present their determination for the physical value of $m_c$, which required calculating hundreds of four-loop propagator diagrams with unitarity cuts and two mass scales. Our final result for the CP- and isospin-averaged branching ratio reads ${\mathcal B}_{s \gamma}^{\rm SM} = (3.54 \pm 0.14)\times 10^{-4}$ for $E_\gamma > 1.6\,{\rm GeV}$ in the decaying meson rest frame. It is in good agreement with the current Particle Data Group average ${\mathcal B}_{s \gamma}^{\rm exp} = (3.49 \pm 0.19)\times 10^{-4}$.

We present a new and upgraded analysis of the inclusive weak radiative decay of the $B$ meson in the standard model and beyond. The ${\mathcal O}(\alpha_s)$ perturbative corrections are included in a formally complete manner. At the order $\alpha_s^2$, exact dependence on the charm quark mass is calculated for the dominant corrections, which removes a sizeable uncertainty that was present in all the previous analyses. The global normalization factor and many of the non-perturbative contributions are expressed in terms of the kinetic-scheme mass of the $b$-quark and the heavy-quark-expansion matrix elements. These parameters are adopted from the most recent semileptonic fits that include ${\mathcal O}(\alpha_s^3)$ corrections and up-to-date experimental results. We find ${\mathcal B}_{s\gamma}^{\rm SM} = (3.54 \pm 0.14)\times 10^{-4}$ for the CP- and isospin-averaged branching ratio of the considered decay in the standard model, with a lower cut on the photon energy $E_\gamma > 1.6\,{\rm GeV}$. It agrees with the current experimental average ${\mathcal B}_{s\gamma}^{\rm exp} = (3.49 \pm 0.19)\times 10^{-4}$, which provides constraints on beyond standard model physics. In particular, we find $M_{H^\pm} > 670\,{\rm GeV}$ at $95\%\,{\rm C.L.}$ for the charged Higgs boson mass in the two-Higgs-doublet model~II.

Artificial atoms provide a versatile platform for engineering atomic-like orbitals, yet spin generally remains a passive degree of freedom in their orbital structure. Here, we introduce the concept of altermagnetic artificial atoms formed by confining electrons with momentum-dependent spin splitting. We show that altermagnetism reconstructs conventional confined orbitals into spin-textured orbitals, with spatially distinct distributions of opposite spin components. The resulting confined spectrum retains a twofold degeneracy protected by the combined $C_{4z}\mathcal{T}$ symmetry. These spin textures persist in higher-energy states, where additional radial structures combine with the characteristic angular spin pattern. Furthermore, strain resolves the degenerate orbital pairs into spin-polarized states, and continuously tunes their energy splitting. Our results establish altermagnetic artificial atoms as a route to engineering spin-dependent orbital structures in quantum-confined systems.

The order of cellulose microfibrils in xylem cell walls is identified using polarized optical microscopy. The line, helix, ring, crossed helix, and twisted helix organizations in a cylindrical shell are the equilibrium states of balanced elastic deformation and surface anchoring. A computational model of the five organizations is established to simulate their birefringent-colored profiles. These five textures present unique optical textures, which are clearly recognized in the cross sections of Eucalyptus grandis. The libriform fiber cell for support has a twisted helical cell wall. The vessel cell for high-speed water uptake consists of a helical layer covered by a layer of vortex array. The ray cell for radial transportation is crossed helical. The microfibril angles versus the radius of the cell wall were measured utilizing the distribution of birefringence colors. In fiber cell walls, the MFA is significantly correlated with the curvature, bending, and surface anchoring, respectively. In vessel cell walls, the vortex array includes focal conic domains of chiral order and topological defects of nematic order, suggesting that the phase transition of cellulose fibrils leads to pattern formation. Liquid crystal phases and patterns in the cell walls reveal how the cell wall thickens and how cells differentiate. Out of the frustration of long, stiff, twisting fibrils packed in slender tubes, trees generate the helical channel networks, transforming the brittle lamina into an elastic, tear-resistant, self-healing tissue.

Numerical studies of noisy Rydberg-atom optimization compress decoherence into a single rate, treating spontaneous decay ($\Gamma$) and dephasing ($\gamma$) as equivalent. We resolve the two as independent Lindblad axes for quantum annealing of unit-disk maximum independent set at fixed annealing time and ask how their relative effect depends on the readout. For the raw readout the size error collapses onto the effective dephasing rate $u=\kappa\Gamma+\gamma$, and at small noise a unit of decay rate degrades the result as much as $\kappa=7.4$ units of dephasing rate; a collapse fit across the whole grid returns 8.3. After greedy completion followed by a $(1,2)$-swap local search, classical post-processing of polynomial cost, the exchange rate falls to $\kappa=1.6$, and at the calibrated operating point of a commercial device dephasing produces three quarters of the noise-induced error instead of two fifths. First-order perturbation theory built from noiseless propagation gives the decay and dephasing susceptibilities of every readout, raw or post-processed, to a few parts in $10^6$ of the full Lindblad result. The raw asymmetry is set at the end of the schedule, where a decay event deletes an atom and a dephasing event leaves the readout unchanged. Post-processing refills most deletions and leaves misplaced atoms, which the two channels produce at comparable rates. Which channel limits a device therefore depends on the readout as well as on the hardware.

We analyze the in-medium modification of the $\phi$ meson mass below the pseudo-critical temperature $T_\text{c}$ at vanishing baryon chemical potential using QCD sum rules. The sum rules are applied separately to the transverse and longitudinal polarization modes of the $\phi$ meson defined relative to the spatial momentum in the medium rest frame. We map out the temperature and momentum dependence of the mass in each mode and quantify the resulting transverse–longitudinal mass splitting. The splitting develops with increasing temperature and momentum.

We investigate the gravitational form factors (GFFs) of the kaon in a proper-time-regularized three-flavor Nambu–Jona-Lasinio model. We treat the kaon as a light–strange pseudoscalar bound state and evaluate its energy–momentum-tensor matrix element using a dressed quark–graviton vertex. By retaining the interaction-induced contact contribution alongside the quark triangle diagrams, we preserve the gravitational Ward–Takahashi identity and ensure the conservation of the total energy–momentum tensor. We determine the light- and strange-quark contributions to the kaon GFFs, contrast them with the corresponding pion results, and extract the associated pressure and shear-force distributions, together with the Breit-frame and transverse light-front mass radii. Explicit flavor-symmetry breaking dictates that the strange sector carries a larger share of the kaon momentum and mechanical response. Consequently, compared to the pion, the kaon exhibits a less negative $D$-term and more compact mechanical distributions, featuring enhanced central pressure and shear. We further show that a Ward–Takahashi-identity-preserving reduction of the $C$-term projection is essential for maintaining the pion low-energy theorem in proper-time regularization.

The Debye screening mass is a fundamental parameter characterizing the screening of chromo-electric fields in a hot quark-gluon plasma. It plays an important role in thermal field theory, entering the description of screening lengths, transport phenomena, heavy-particle interactions in the early Universe, and the dimensional reduction program that connects thermal QCD to effective three-dimensional theories. In this contribution, we revisit the reduction strategy that serves to organize the large number of terms that contribute to the screening mass at the three-loop level, applying recent advances based on canonical forms of thermal (sum-) integrands. We emphasize the role of integration variable shifts, and discuss how canonical representations of thermal integrands may simplify future high-order calculations in hot QCD.

We calculate the superheating field $H_s$ of a type-II superconductor with a large Ginzburg-Landau parameter from the isotropic Eliashberg theory. It is shown that the temperature dependencies of $H_s(T)$ can be obtained from a thermodynamic approach for different scattering parameters $p=\hbar/2\pi\tau_Nk_BT_c$ in a wide range of the nonmagnetic impurity scattering times $\tau_N$ ranging from the clean $(p\ll 1)$ to the dirty $(p\gg 1)$ limits. Specific calculations were done for Nb and Nb$_3$Sn using their electron-phonon spectral functions extracted from tunneling measurements. We show that the ratio $H_s(T,p)/H_c(T)$ calculated from the Eliashberg theory exceeds that of the weak coupling BCS model, where $H_c$ is the thermodynamic magnetic field. We also show that, even though nonmagnetic impurities are pairbreakers in the current-carrying state, $H_s(0,p)$ for Nb$_3$Sn at $T=0$ has a maximum at $p\approx 0.2$ at which the ratio $H_s/H_c$ is about $6\%$ higher than that in the BCS clean limit.

Grover's quantum search algorithm provides a fundamental quadratic speedup for unstructured datasets, reducing query complexity from $\mathcal{O}(N)$ to $\mathcal{O}(\sqrt{N})$. However, the algorithm's reliance on precise iteration counts leads to the “soufflé problem,” where over-rotation results in a sharp decline in success probability. This limitation is particularly restrictive when the number of solution states, $M$, is unknown. In this work, we present an ancilla-mediated fixed-point quantum search algorithm that achieves robust convergence by mapping the solution amplitude to a dedicated ancilla qubit. Unlike existing phase-matching fixed-point methods, our approach utilizes Grover's real-plane reflections, thereby maintaining the intuitive geometric architecture of the original algorithm. We demonstrate that this method achieves a success probability of at least $92.6\%$ with a query complexity of approximately $\mathcal{O}(\sqrt{N/M})$, effectively bridging the gap between standard amplitude amplification and robust fixed-point convergence.

On-chip communication in optical neural networks is commonly done via waveguides which results in large system footprints. A compact alternative is to broadcast light signals between nano-optoelectronic components in free space and tailor the light field distribution using sub-wavelength nanophotonics. We propose and simulate nanoplasmonic metal structures in combination with III-V nanowire emitters and receivers to create an optical network in which the shape and position of these nanostructures create varying weights between the nano-optoelectronic nodes. Using Finite Difference Time Domain modelling, we investigate systems of experimentally verified nanowire optoelectronics combined with nanoplasmonic structures that can be made in the same fabrication step as electrical contacts powering the nanowires. We investigate both individual nanowire/antenna devices as well as networks corresponding to two layers in a neural network. We show that directed communication from a nanowire node can be significantly altered using Yagi-Uda antennas. Modifying the antenna with an asymmetric director component enables the directing of light several different angular directions simultaneously. We find that highly variable complex weight distribution between the connections in two seven node layers can be achieved depending on the combined geometry of the antenna components. The possible weight distributions in compact layers of nanowire nodes could be used for creating a variety of neural networks with complex connectivity. The concepts can be generalized to other types of nanoscale emitter/receiver systems.

The recent discovery of long-sought dice flat band in layered YCl electride has opened up rich possibilities of correlation and topological physics in dice lattice systems [Nature Communications 17, 2213 (2026), arXiv:2509.05958]. Here, we reveal a plethora of distinctive correlated topological phases in a generic layered dice lattice system at band filling of $\nu =4$ under on-site Hubbard interactions: (i) the system is an intrinsic sublattice anti-ferromagnetic (AFM) quantum spin-valley Hall insulator; (ii) a circularly polarized light (CPL) drives the AFM spin-valley insulator into a Floquet odd-parity $f$-wave altermagnet(AM) insulator; (iii) a vertical displacement field turns the Floquet $f$-wave AM insulator into a spin-valley-layer-polarized Chern insulator, with the sign of spin, valley and Chern number all controlled by the direction of the displacement field. Our results not only establish the layered dice lattice as a versatile platform for electrically switchable magnetic and topological phases, but also provide an all-electrical scheme for integrated spin-valley-layertronics for non-volatile information storage and processing.

We numerically study a perforated all-dielectric metasurface based on the magnetic semiconductor GaMnAs. Near the anapole state, the structure combines high transmittance with a moderate magneto-optical intensity effect. The absolute transmission modulation is enhanced by about a factor of five compared with a smooth film, while the metasurface transmittance reaches 81%. The enhancement is associated with strong field localization in the magneto-optically active material and suppression of the electric-dipole radiation channel in the anapole regime.

Using state-of-the-art numerical techniques, we investigate how quantum phase fluctuations and quasiparticle tunneling shape the behavior of a small-capacitance Josephson junction across Ohmic, sub-Ohmic, and super-Ohmic dissipation regimes. We show that increasing the Ohmic dissipation strength drives a Berezinskii-Kosterlitz-Thouless quantum phase transition at thermodynamic equilibrium. Deviations from Ohmic behavior profoundly alter this scenario: the super-Ohmic regime exhibits no phase transition, whereas the sub-Ohmic regime displays a continuous second-order transition, consistent with the universality classes of the spin-boson model. Within the Ohmic regime, real-frequency linear-response calculations reveal that the phase particle does not undergo the commonly assumed diffusive-to-localized crossover. Instead, finite resistance progressively suppresses the singular zero-frequency response, producing a ballistic-to-localized change in the dynamics. At finite frequencies, coupling to the environment generates a long-lived excitation in the charge response, which evolves into a resonance as the subgap and shunt resistances are reduced.