Papers

We study the influence of an external magnetic field on the Goos-Hänchen (GH) shift and the group delay time (GDT) in monolayer WSe$_2$ in the presence of a magnetic barrier. The transport properties of Dirac-like carriers are obtained by solving the effective low-energy Hamiltonian and evaluating the corresponding transmission amplitudes. The GH shift and the GDT are subsequently extracted from the phase of the transmission coefficient. We systematically analyze their dependence on the magnetic field strength, incident energy, angle of incidence, and barrier width, with particular emphasis on the spin and valley degrees of freedom associated with the $K$ and $K'$ valleys. Our results show that the magnetic barrier strongly modulates both the GH shift and the GDT, leading to oscillatory behavior and pronounced spin-valley-dependent transport characteristics. Remarkably, the magnetic field enables selective control of the lateral shift and traversal time of carriers for each spin and valley channel, allowing for tunable spatial and temporal separation of electronic wave packets. This provides a mechanism for manipulating fermionic trajectories after transmission through the barrier in a highly controllable manner. Such tunability opens promising avenues for designing nanoscale devices based on spin and valley filtering, as well as for potential applications in information storage and processing within spintronic and valleytronic platforms.

We construct a new family of random fields on the Heisenberg group $\mathbb{H}$, the sub-Riemannian analog of $\mathbb{R}^{n}$. These fields are generalized random eigenfunctions of the sub-Laplacian on $\mathbb{H}$, and can be viewed as the sub-Riemannian counterpart to the Berry random wave model in $\mathbb{R}^{n}$. The construction of such waves relies on the representation theory of $\mathbb{H}$, and differs from the Euclidean case because of the presence of infinite-dimensional unitary irreducible representations. This work represents a first step towards studying random waves and their geometry in sub-Riemannian spaces.

We present a comprehensive three-dimensional atmospheric neutrino flux calculation based on the well-recognized simulation framework develeped by Honda and his collaborators, incorporating for the first time the muon propagation inside the Earth and its subsequent decay or nuclear capture. Other updates of essential input models include: the AMS02-based primary cosmic ray model, IGRF2020 geomagnetic field, and muon-recalibrated hadronic interaction model. The calculation covers seven detector sites across diverse geomagnetic environments, spanning 10~MeV to $10^4$~GeV. Significant site-dependent differences appear at $E_\nu < 10$~GeV, with $\nu_\mu$ flux at IceCube approximately twice that at JUNO below 1~GeV. Compared to HKKMS15, deviations of 2%–10% are attributed to the updated input models. Below 100~MeV, we present precise flux results, revealing that muon propagation contributes a globally significant component to the low-energy neutrino flux at all sites, with an approximately site-independent absolute increment. The hadronic uncertainty is re-estimated across the energy range using the updated hadronic interaction model, with significant reduction of the systematic error compared to previous calculations. These results provide essential inputs for neutrino oscillation and rare-event search experiments including JUNO, Super-Kamiokande/Hyper-Kamiokande, DUNE, KM3NeT/ORCA, and IceCube, as well as direct dark matter detection experiments facing the neutrino fog.

In situ knowledge of array geometry enables mechanically flexible phased arrays to recover beam-steering performance under deformation without receiver-side RF feedback. This work presents a comprehensive engineering study of curvature-based shape sensing, combining numerical sampling-density and measurement-noise analysis, physical modeling of sensor response, and experimental shape and RF characterization. A study of 11,000 Bézier curves quantifies reconstruction error versus curvature-sampling density and noise, guiding the selection of nine sensing locations. A physical model relates PCB curvature to strain-gauge output voltage, with predictions compared against calibrated sensor measurements. The sensing system is integrated with an eight-element, 6-GHz flexible array and a low-cost, size-scalable, digitally controlled eight-channel phase-shifting module providing 360{\deg} tuning with better than 7-bit effective resolution. Across 12 fixture-conformed shapes, including five previously reported cases, the average reconstruction error is 0.06$\lambda$. Three additional air-suspended configurations, not prescribed by analytical curves, show an average positional difference of 0.095$\lambda$ between curvature-based and image-based estimates. Measured radiation patterns demonstrate broadside correction and steering to $\pm$30{\deg}. These results provide quantitative engineering guidance for designing and characterizing curvature-based shape-aware flexible phased arrays.

Determining absolute/convective instability boundaries conventionally requires repeated saddle searches in the complex-wavenumber plane and a subsequent scan of the physical parameter space to locate zero absolute growth. Such nested calculations become costly and sensitive to modal branch association for large non-normal eigenvalue problems. This work develops a direct continuation method for neutral stationary-saddle boundaries of frequency-affine generalised eigenvalue problems. The zero-group-velocity condition is expressed as an adjoint solvability residual and solved together with the direct and adjoint eigenproblems, complex gauge constraints and the neutral-growth condition. The resulting one-dimensional solution manifold in the combined state–parameter space is tracked by scaled pseudo-arclength continuation, allowing parameter folds to be crossed without switching the physical continuation variable. The formulation recovers the analytical Ginzburg–Landau boundary and, for a Gaussian-wake Orr–Sommerfeld problem, agrees with separately formulated finite-difference saddle corrections to approximately $10^{-8}$ in relative critical Reynolds number. Compared with nested complex-wavenumber and parameter-plane saddle scanning, the tested scans require $8.1$–$52.2$ times the wall time of the direct adjoint continuation. Extrapolation of the measured cost–accuracy trend to a boundary error of $E_H\sim10^{-6}$ suggests an estimated cost ratio of approximately $1.8\times10^{4}$ in favour of the direct continuation. Application to a coupled Oldroyd–B free-surface film reveals genuine folds of the neutral-saddle manifold and a re-entrant CI–AI–CI boundary geometry for the selected saddle family.

We propose a phenomenological model of the Global Neuronal Workspace (GNW) in which early sensory processing generates an effective complex-valued landscape governing the dynamics of high-level stimulus representations. This landscape provides a dynamical bridge between sensory encoding and conscious access, enabling both processes to be described within a unified framework. High-level representations are encoded in a cloud function defined on a Hilbert space over a perceptual state space, thereby combining the holistic structure of mental images with a neural implementation. Its dynamics is governed by a nonlinear Schrödinger-type equation in imaginary time with a non-Hermitian, non-normal Hamiltonian and a nonlinear Lotka–Volterra-type term that preserves norm and enables spatially nonlocal interactions. The Hermitian and anti-Hermitian parts of the Hamiltonian generate complementary processes: recognition via dissipative localization at minima of the GNW landscape and information broadcasting via spatial spreading across the state space. The resulting dynamics reproduces the subliminal–preconscious–conscious hierarchy of sensory processing. Conscious access corresponds to the emergence of a bound state, which occurs only when both the GNW landscape depth and the degree of top-down attention exceed threshold values. The resulting framework provides a tractable dynamical description linking sensory processing, attention, and conscious access within a unified dynamical setting.

We study the quantum Wasserstein distances of De Palma and Trevisan associated with quadratic costs generated by self-adjoint observables in arbitrary finite dimension. We first show that any positive semidefinite cost operator is determined by the corresponding distance on pairs of pure states. For nonzero observable-generated quadratic costs, we then prove that the full isometry monoid consists exactly of unitary and antiunitary conjugations if and only if the distance is invariant under unitary conjugations on pure states. These conditions are equivalent to isotropy of the cost on the traceless subspace. They are also equivalent to a geometric characterization: two states attain the Wasserstein diameter exactly when their supports are orthogonal. It already suffices to impose this condition on pairs of pure states. We construct explicit mutually inverse maps between observable-generated quadratic costs and Hilbert–Schmidt frame-type operators formed from the traceless parts of their generators. This correspondence also expresses the transport variational problem directly in terms of the frame operator. For every such cost $C$ on a $d$-dimensional Hilbert space, the minimal number of self-adjoint generators equals the rank of its recovered frame operator $\Theta(C)$, and is therefore at most $d^2-1$. Nonzero isotropic costs require exactly $d^2-1$ generators, attaining the largest minimal generator number that any observable-generated quadratic cost can require. Their arbitrary generating families give tight frames, while their minimal realizations give scaled Hilbert–Schmidt orthonormal bases of the traceless subspace. These symmetry, frame, and diametral characterizations determine the same one-parameter family of quantum Wasserstein distances.

In this paper, we construct braiding structures on the multi-interval Jones-Wassermann subfactor planar algebra associated with any unitary modular fusion category. Utilizing this construction, we provide a new proof of the self-duality of these subfactors. Furthermore, we demonstrate that these braidings induce a projective unitary representation of the balanced superelliptic mapping class group; consequently, these structures effectively encode the non-trivial higher-genus data of the underlying category. As an application of this correspondence, we derive a generalized Verlinde formula as 2-box Fourier duality of the planar algebra.

Reflection of waves at interfaces is conventionally governed by Snell's law, which follows from conservation of momentum parallel to the interface. Here we show experimentally that caustic spin-wave beams in anisotropic media obey a fundamentally different reflection mechanism. Applying time-resolved Kerr microscopy to a yttrium iron garnet waveguide, we observe that reflected beams are selected by transitions between caustic points on the anisotropic iso-frequency contour rather than by momentum conservation. As a consequence, the reflected carrier wave vector and wavefront orientation exhibit trends opposite to those predicted by Snell's law. By tuning the magnitude and orientation of an external magnetic field, we continuously control the resulting reflection process and beam routing. Our results establish caustic-point transitions as a distinct reflection law for anisotropic wave beams and provide a route towards reconfigurable magnonic beam steering.

Quasiperiodic lattices can host critical eigenstates, whereas nonreciprocal hopping in non-Hermitian lattices can induce non-Hermitian skin effect. In this work, we investigate localization phenomena in a Hatano–Nelson model with quasiperiodically modulated hopping amplitudes, where nonreciprocity arises from unequal modulation strengths of the right and left hoppings. Using a non-unitary gauge transformation, we map the non-Hermitian system into a Hermitian quasiperiodic system and obtain an exact analytical expression for the Lyapunov exponent in the thermodynamic limit. Under periodic boundary conditions, inverse participation ratios and finite-size scaling analysis are used to identify the quasiperiodic critical regimes. The comparison shows that parameter regimes hosting quasiperiodic critical states under periodic boundary conditions can exhibit the non-Hermitian skin effect under open boundary conditions. Furthermore, the non-Hermitian skin effect associated with quasiperiodic critical regimes is also observed in representative long-range hopping models and multiband extensions. Our results provide an analytically controlled perspective on how quasiperiodicity, modulated nonreciprocity, and boundary conditions jointly shape the non-Hermitian skin effect in critical regimes.

The influence of ferritic steel on low-shear stellarator/heliotron magnetic configurations is investigated for the Heliotron J device using a point dipole magnetisation model. By numerically evaluating ferritic steel plates assumed at several locations inside the Heliotron J vacuum vessel, the changes in the rotational transform and magnetic island width are shown to be sensitive to the installation location. This location sensitivity arises from the toroidal variation of poloidal mode coupling between the background nonaxisymmetric field and ferritic-steel perturbation, rather than being determined solely by the perturbation amplitude. The resulting mode coupling can enhance the resonant vacuum magnetic perturbation at specific locations. Ferritic steel plates placed on the outer side of a straight section produce the most significant changes in the magnetic topology and exhibit the highest sensitivity to violations of the $M=4$ toroidal periodicity. Additionally, we show that appropriate arrangements of passive magnetic dipoles can reduce the effective helical ripple while preserving the vacuum magnetic well depth in Heliotron J, and can induce a stellarator-asymmetric boundary perturbation in low-field experiments.

The future CTAO will reach a sensitivity and energy resolution never obtained until now by any other high-energy gamma-ray experiment. Studying the atmospheric conditions during the CTAO observations, namely the extinction and backscatter coefficients, permits a very precise evaluation of the atmospheric UV absorption, a parameter that directly affects the energy and flux spectra of the CTAO-studied sources. This paper describes the motivation for the LUPM Raman Lidar system, a Lidar specifically designed to fulfill the CTAO requirements for the south site in Chile. Preliminary results obtained during a two-year campaign at the OHP Observatory are presented. Our results include estimations of the extinction, back-scatter, and Lidar ratio at both 355 and 532 nm and confirm the conformity of our prototype to the CTAO requirements

Newell's simplified car-following model offers behavioral interpretability with minimal parameters, yet the temporal limits within which it holds during actual car-following interactions, particularly in lane-free traffic, remain poorly understood. This has direct consequences for Newell parameter estimation. This study evaluates the model using high-resolution UAV trajectories from a lane-free highway corridor in Chennai, applying two independent estimation approaches: linear regression of the speed-spacing relationship (aggregate and pair specific), and a shifting optimization method that recovers parameters by minimizing spacing variance. A boundary-corrected variant of the shifting method is then introduced to isolate transitional regimes at interaction endpoints while preserving the original Newell formulation. Pair-specific regression substantially outperforms the aggregate specification ($R^2$ = 0.84 vs. 0.54), underscoring pronounced driver heterogeneity. Parameters recovered via trajectory shifting are statistically equivalent to regression estimates, providing independent support for the trajectory translation principle underlying Newell's model. Boundary correction markedly improves model fit, increasing the mean $\bar{R^2}$ from 0.66 to 0.95, and is preferred for 81% of pairs according to the Bayesian Information Criterion (BIC). The results indicate that interaction boundary effects, rather than failures of the core behavioral assumptions, are the principal source of estimation error in this setting. Correcting for these effects improves parameter recovery without compromising model parsimony. Boundary correction is therefore a necessary step in trajectory-based calibration of Newell-type models, with implications for traffic state estimation and microscopic traffic simulation.

We introduce a framework to identify the radial transition in mass reconstruction reliability between strong and weak gravitational lensing in galaxy clusters. In weak lensing reconstruction, the convergence recovered from the reduced shear is subject to the mass-sheet degeneracy. We demonstrate that the degeneracy itself can serve as an indicator of the reconstruction reliability, and introduce a spatially resolved parameter $\lambda(r)$ to characterize this as a function of radius. We validate this approach on simulated clusters with realistic observational noise, and show that the radial behavior of $\lambda(r)$ captures the relative reliability of the two probes. Furthermore, when the global mass-sheet parameter $\lambda$ is constrained directly using strong lensing information, the tightest constraints arise where the two probes achieve comparable precision. This provides a quantitative basis for joint strong and weak lensing mass reconstruction.

We study the five-dimensional Schwarzschild-Tangherlini solution, with particular attention to its geodesic structure and massless scalar perturbations. In the probe limit, we present two applications. First, we compute the scattering angle for unbound geodesics showing both post-Newtonian and post-Minkowskian type expansions, and succeeding in resumming the resulting series in terms of hypergeometric functions. Second, we derive the Lyapunov exponent for deviations from a critical circular orbit, which is relevant to the eikonal estimation of quasinormal modes. We then investigate the dynamics of massless scalar $(s=0)$ perturbations, for which the radial equation becomes a Reduced Confluent Heun equation. In this $d=5$ Schwarzschild-Tangherlini case we develop an original extension of the standard Mano-Suzuki-Takasugi (MST) formalism and validate the construction by computing the renormalized angular-momentum parameter $\nu$, whose value agrees with an independent determination based on the quantum Seiberg-Witten formalism. Finally, we analyze the energy flux from circular orbits, obtaining post-Newtonian results through 2.5PN order.

We demonstrate that electronic correlations in low-dimensional systems can induce topological phases starting from a topologically trivial noninteracting band structure. Using an advanced cluster-diagrammatic many-body approach applied to the one-dimensional extended Hubbard model, we show that tuning the nonlocal Coulomb interaction drives the emergence of bond-order-wave (BOW) and charge-density-wave (CDW) phases. Despite being interaction-driven and symmetry-broken, these states admit an effective low-energy single-particle description. In particular, the BOW phase maps onto an effective Su-Schrieffer-Heeger model, while the CDW phase, with subleading bond-order correlations, corresponds to a Rice-Mele model. Both phases exhibit a nontrivial topological character, manifested by the presence of localized edge states. Our results establish a mechanism by which nonlocal electronic correlations generate emergent topology in correlated systems.

Nonadiabatic driving in ultrastrongly coupled light–matter systems is commonly regarded as a source of errors, as counter-rotating interactions convert vacuum fluctuations into real excitations through the dynamical Casimir effect (DCE). Here we show that, instead, the DCE can be harnessed as a resource for engineering nonclassical states of light. Considering a cavity mode ultrastrongly coupled to a frequency-tunable qubit, we employ optimal quantum control to design driving protocols that convert vacuum fluctuations into targeted states. Numerical optimization reveals a versatile and robust approach for the deterministic preparation of a broad class of nonclassical states, illustrated here through Fock states, squeezed states, and Schrödinger-cat-state superpositions.

Photonic integrated circuits (PICs) have emerged as a key platform for information processing, including optical communication and computing. As PIC complexity increases, fabrication-induced response deviations accumulate, making post-fabrication trimming critical for unlocking their full potential. Here, we demonstrate that silicon ion implantation enables scalable, ultra-low-loss trimming of cladded PICs by locally forming a high-index silicon-rich region. Structural characterization confirms that the silicon-implanted nanoregion is confined to the cladding without observable damage to the underlying waveguide. The implantation-induced excess loss is below 0.001 dB per {\pi} phase shift, while the optical response remains stable over a four-month observation period. Automated trimming is demonstrated on a photonic crossbar array, reducing the average channel output variation from 78.5% to 5.9%. These results establish a practical route towards automated, ultra-low-loss post-fabrication trimming for large-scale cladded PICs.

We present a direct measurement of the Ly$\alpha$ escape fraction, $f^{\rm Ly\alpha}_{\rm esc}$, for H$\alpha$ emitters (HAEs) at $z\simeq6.2$ in the JWST CEERS field by combining JWST/NIRCam F470N imaging with Subaru/HSC NB872 imaging. This unique pair of narrow-band filters enables the simultaneous measurement of H$\alpha$ and Ly$\alpha$ fluxes from galaxies during the epoch of reionization (EoR). We select 84 HAEs from F470N excesses, among which 56 have reliable NB872 photometry and 14 are detected in Ly$\alpha$. The completeness-weighted stack of the HAE sample yields a median $f^{\rm Ly\alpha}_{\rm esc}$ at $z\simeq6.2$ of $0.106^{+0.066}_{-0.044}$, which is in good agreement with recent measurements at similar redshifts. We further find that the stacked $f_{\rm esc}^{\rm Ly\alpha}$ shows no statistically significant change as the H$\alpha$ luminosity threshold is lowered over the range probed by our sample. If Ly$\alpha$ escape traces Lyman continuum leakage, this may suggest that relatively H$\alpha$-luminous HAEs, rather than only the faintest ones, can provide an important contribution to the ionizing photon budget during the EoR. For individual galaxies, $f^{\rm Ly\alpha}_{\rm esc}$ positively correlates with Ly$\alpha$ equivalent width and negatively correlates with the UV continuum slope $\beta$. We also find a tentative trend toward higher $f^{\rm Ly\alpha}_{\rm esc}$ at smaller rest-frame UV sizes, but no significant correlation with SED-derived $E(B-V)$ or rest-frame optical size. Although based on a limited sample, these results suggest that the galaxy-to-galaxy variation in $f_{\rm esc}^{\rm Ly\alpha}$ may be more closely linked to compact, low-attenuation star-forming components traced by the UV continuum than to global dust attenuation or the overall stellar structure.

Gas in debris discs is thought to be either inherited from the protoplanetary stage or released from the solid, rocky content of planetesimal belts. Its presence can impact planetary atmospheres and their potential for habitability, which stresses the need to ascertain its origin and composition. Most detections to date are around main-sequence stars, with only a few gas-bearing debris discs identified around pre-main-sequence stars, mainly through millimetre CO line searches. We investigate narrow gas absorption features superimposed on the photospheric Ca II K & H and Na I D1 & D2 lines in a sample of 125 pre-main sequence and 5 relatively young (<17Myr) stars. All stars are associated with IR excess emission indicative of presence of a debris disc. By comparing their residual spectra (photosphere-subtracted) to those of nearby stars, interstellar cloud velocities, and stellar radial velocities, we test whether interstellar absorption is the culprit and ascertain circumstellar gas origin. Using these methods, out of the 130 targets, we identified two new gas-bearing debris discs: TYC7879-1373-1, which exhibits stable absorption, and HIP30414, which shows variable gas absorption features linked likely to ongoing accretion. Both these systems are pre-main-sequence stars younger than 5Myr. TYC6822-283-1 has absorption features of inconclusive origin. This study increases the number of currently known very young (<10Myr) debris discs with circumstellar gas to eight, paving the path to future systematic studies of objects caught in transition from protoplanetary to debris disc stages.

A massive fermion around a charged black hole provides a gravitational analogue of atomic bound states and their relaxation. In this work, we study this system by formulating the radial equation as a coupled matrix system and constructing the Green's function with ingoing boundary conditions at the horizon and decaying boundary conditions at infinity. In the weak-coupling scenario $|qQ|\sim mM<1$, a matrix matching scheme gives an improved analytic expression of quasi-bound-state spectrum, including fine-structure corrections and more accurate decay widths. The extremal Reissner-Nordström case ($|Q|=M$) is treated separately and shown to be the smooth limiting result of the non-extremal spectrum. We further analyze the branch-cut contribution to the time-domain Green's function in the late-time limit. We confirm an oscillatory power-law behavior in intermediate late-time regime $1/m < t < 1/m^3M^2$. In the far late-time regime $t>1/m^3M^2$, the activation of the quasi-bound states produces an $t^{-5/6}\exp(-\eta t^{1/3})$ suppression with a chirping phase before the asymptotic $t^{-5/6}$ tail previously found in the limit $t\to\infty$. Direct time-domain simulations support this distinction and show how the quasi-bound contribution coexists with the familiar power-law component.

Electrical contacts often limit the performance of atomically thin semiconductor devices. The Schottky barrier height (SBH) is conventionally treated as a local interface property, yet reported values for the same metal/2D-semiconductor contact vary by hundreds of meV. Here we show that, in top contacts, the effective SBH exhibits a pronounced nonlocal electrostatic dependence on defects near the contact edge, beyond the conventional local interface framework. A nonlocal electrostatic model, supported by density-functional-theory-based transport calculations for Ti–MoS$_2$ and Au–MoS$_2$, captures the large, metal-dependent variations in SBH as a function of defect position relative to the contact edge. These results provide a unified explanation for the longstanding variability in experimentally extracted SBHs and establish nonlocal electrostatics, mediated by edge-proximal defects, as a key mechanism governing carrier injection in 2D contacts.

Ultralight dark matter can interact with Standard Model particles via gravitational and non-gravitational interactions. Through such interactions, it can leave distinctive signals in gravitational-wave experiments. In this work, we investigate signals induced by ultralight dark matter quadratically coupled to the Standard Model in the future space-borne gravitational-wave detector, the Laser Interferometer Space Antenna (LISA). Due to the quadratic nature of the coupling, dark matter signals appear at two distinct frequencies: the frequency corresponding to twice the dark matter mass, and frequencies below the typical dark matter kinetic energy. We analyze both contributions and show that LISA can surpass current constraints from terrestrial and astrophysical probes in certain mass ranges. We also find that dark matter signals in LISA are free from screening effects which significantly limit the sensitivity of terrestrial experiments.

Context. THÉMIS was initially built as a calibration-free telescope, with the polarisation analysis performed in F1 focus, before any oblique reflection. Recently, the telescope was improved with installation of an Adaptive Optics apparatus. Aims. We would like to show you that it remains a calibration-free telescope, even if the two beams able to provide the light polarisation, are now separated in front of the cameras only. Methods. This is obtained owing to an adaptation of all the oblique reflections along the ray path. Results. We present raw images taken across a sunspot, with three lines: two polarisable lines, which display the sunspot magnetic field polarisation, linear and circular, and one unpolarisable line, which does not display any polarisation, which shows that the telescope is essentially free of any instrumental polarisation, because, if this line had showed any polarisation, this polarisation would have been of instrumental origin. Those images were recorded on September 12, 2024. We also present vector magnetic field, vector current density and vector Lorentz force maps obtained in July 2025, which are in accordance with previous results: circular currents wrapping spots clockwise about a positive polarity spot and counterclockwise about a negative polarity spot, and centripetal Lorentz force maintaining sunspots. Conclusions. As a result, THÉMIS remains a calibration-free telescope.

The nuclear shell model is a general way of expressing the many-body nuclear Hamiltonian and deciphering the underlying nuclear structure. In today's era of modern and high-power computation, the primary limitation of the nuclear shell model is the enormous dimensionality of its Hilbert space, which far exceeds available storage capacity and prevents the diagonalization of the full Hamiltonian matrix in that space. Quantum computing offers a scalable solution to bypass this curse of dimensionality. In this work, we introduce a single-run quantum simulation capable of obtaining multiple shell-model eigenstates simultaneously. The nuclear Hamiltonian is transformed from a bit to a qubit basis using the Jordan-Wigner transformation, explicitly preserving fermionic anti-commutation. We employ a Subspace Search Variational Quantum Eigensolver (SSVQE) along with an Adaptive Derivative-Assembled Pseudo-Trotter (ADAPT) ansatz to construct the quantum circuit required to solve the shell-model problem. The ADAPT-SSVQE algorithm uses a symmetry-preserving single and double-excitation operator pool and optimizes a weighted energy sum to obtain the simultaneous convergence of all eigenstates within a targeted MJ subspace, eliminating the need for post-processing efforts to extract excited spectra. We benchmark this approach by solving the problem for two and three identical nucleons in a j = 9/2 orbital, successfully extracting five and ten mutually orthogonal states, respectively, within a 10-qubit active space. The algorithm achieves spectroscopic accuracy, in simulation, relative to exact diagonalization and intrinsically restores total angular momentum (\hat{J}^2) symmetry.

Maintaining carbon steel in marine environments requires surface treatments capable of simultaneously removing corrosion products and chloride contaminants whilst modifying the residual oxide layer. In this study, salt-contaminated SS400 carbon steel was treated using a Q-switched pulsed fibre laser characterized by a full width at half maximum (FWHM) of approximately 150 ns and a decaying tail extending to about 600 ns. The pulse energy was fixed at 1 mJ, and the repetition frequency was varied between 50 and 200 kHz to investigate the effects of cumulative thermal accumulation. Under 100 W (100 kHz) conditions, WDS-EPMA analysis confirmed that Na and Cl levels dropped to near-background values, demonstrating the comprehensive removal of sea-salt-derived contaminants. SEM observations revealed the transition of the porous rust layer into a dense, laser-modified layer, whilst XPS analysis confirmed the suppression of the $\text{Fe}^{3+}$ satellite feature in the $\text{Fe}$ $2p$ spectrum, establishing a distinct phase transformation from a haematite-dominant rust to a protective magnetite-rich scale. These results elucidate a single-step, two-stage mechanism: the high-peak-power leading edge of the pulse drives the ablation of the corrosion layer, whilst the 600 ns trailing tail delivers continuous thermal energy that promotes oxide resolidification and phase transformation. This approach offers a promising, non-contact methodology capable of concurrent decontamination and surface functionalisation in a single processing step.

Regular black holes in Horndeski theories must have stable horizons and regular centers. We study static, spherically symmetric, asymptotically flat configurations with a time-independent scalar. The horizon branch on which the scalar kinetic term $X$ remains nonzero is generically obstructed by divergent propagation speeds or ghost/gradient instabilities, aside from special degeneracies. On the regular branch, where $X$ vanishes at the horizon, analyticity at the relevant $X=0$ endpoints reduces the leading scalar equation to finite sets of Taylor coefficients. For nondegenerate shift-symmetric theories this gives a nonperturbative current no-hair theorem: the scalar is constant and the metric is Schwarzschild, hence centrally singular for nonzero ADM mass. For non-shift-symmetric positive-power couplings, the corresponding exclusion applies to the perturbative branch continuously connected to Schwarzschild. We also classify marginal nonanalytic departures: covariant regularity fixes the scalar-Gauss-Bonnet chain as the unique marginal nonanalytic completion. Hairy black holes in this completion evade the analytic current step but remain centrally singular.

Calcium-ion batteries (CBs) represent an alternative to lithium-ion technology but their advancement is limited by the lack of high-performance intercalation cathodes. Identified via computational screening, post-spinel CaV$_2$O$_4$ has emerged as a promising candidate, though its practical application is hindered by limited electrochemical capacity. Hence, we investigate the thermodynamic and ionic transport characteristics of Ca$_x$V$_2$O$_4$ ($0 \leq x \leq 1$) in this work, by integrating the cluster expansion formalism with Monte Carlo simulations and density functional theory based calculations. We construct the temperature-composition phase diagram of Ca$_x$V$_2$O$_4$ revealing several stable phases ($\alpha$ through $\zeta$) that can appear during electrochemical operations at different voltages. Importantly, we observe the formation of the $\varepsilon$ phase at $x \sim 0.83$ across a 370-590~K temperature window via invariant reactions, which agrees with observations in the experimental voltage profiles. Further, migration barrier calculations confirm that Ca mobility is severely impeded within the $\alpha$ ($x \sim 0$) and $\gamma$ ($x \sim 0.5$) phases. With the strong Ca-vacancy ordering contributing to the high barrier in $\gamma$ and the persistent two-phase region stretching across the $\delta$ ($x \sim 0.67$) and the $\gamma$ phases, we expect the accessible electrochemical capacity in the CaV$_2$O$_4$ system to be kinetically limited to at most half the theoretical capacity at 298~K, in agreement with experiments. Strategies including cation doping and particle size reduction can be considered to flatten the potential energy landscape of $\gamma$ and improve Ca mobility. Our computational findings highlight the interplay between stability and transport and provide design strategies that can enable the practical use of CaV$_2$O$_4$ as a CB cathode.

The transport of inertial particles in unsteady flows is often governed by the competition between multiple migration mechanisms. We investigate the interplay between inertia-induced drift and thermophoretic migration in a time-periodic vortex containing a localized temperature field. Starting from the small-Stokes-number limit of the particle equations of motion, we derive a cycle-averaged radial migration model describing the slow evolution of suspended particles over timescales much longer than the forcing period. The competition between outward inertia-induced drift and inward thermophoretic migration gives rise to stable and unstable fixed points of the reduced radial dynamics, corresponding respectively to particle trapping states and separatrices bounding trapped trajectories. The existence and location of these states are shown to be governed by the dimensionless control parameter $\Pi$, which measures the relative strength of inertia-induced transport to the thermophoretic transport. As $\Pi$ is decreased below a critical value, the stable and unstable fixed points coalesce and disappear, resulting in the loss of particle trapping. Phase portraits, bifurcation diagrams, and local asymptotic analysis demonstrate that trapping is destroyed through a saddle-node bifurcation. The transition is further characterized by the vanishing of the dominant eigenvalue and the associated divergence of the relaxation time, indicative of critical slowing down. Additional calculations employing various other velocity and temperature profiles demonstrate that the trapping-loss mechanism is robust and not specific to a particular profile.

Quantum linear solvers (QLSs) offer the potential for quantum advantage in solving quantum chemical problems, but assessing such an advantage hinges on determining condition number ($\kappa$) scaling, which itself is computationally challenging. While a recent work applied the HHL algorithm to single-reference linearized coupled cluster (SRLCC), the validity of the framework is restricted to weakly correlated regimes. We thus begin by extending QLS-SRLCC to its multi-reference form, the internally contracted multi-reference LCC (QLS-icMRLCC). We then analyze $\kappa$ scaling across a diverse range of systems as well as bases in both QLS-SRLCC and QLS-icMRLCC, using three complementary diagnostics that range from explicit computations to use of indirect structural indicators: (i) direct calculations of $\kappa$, (ii) scaling of the ratio of maximum to minimum diagonal entries of an $A$ matrix, and (iii) structural analyses of the $A$ matrices based on a recently proposed conjecture that we adapt to the QLS-LCC problem. The three approaches yield broadly consistent predictions, with our numerical results indicating a slow-growing $\kappa$ scaling in system size for the sampled systems. For icMRLCC, however, the observed behaviour depends on the reference active space, leaving the broader prospects of quantum advantage with it less certain. This finding, when combined with our arguments on sub-linear scaling of sparsity (when excitation rank>2), supports the prospects of exponential advantage for QLS-LCC. However, the prospects of a QLS-level advantage do not necessarily translate to a speed-up in an end-to-end workflow. Finally, up to 28-qubit HHL-icMRLCCSD numerical calculations on potential energy curves of model systems containing up to four atoms recover the ground state energies with about $0.012\%$ errors relative to benchmark classical methods.