Papers

We elucidate the stress in a system of active Brownian particles augmented with translational and rotational inertia (ABP+TRI). Stress tensors are derived for periodic systems as well as systems confined between walls by employing Lagrange's equations of motion of the first kind for the rotational motion. Using Langevin simulations of an ideal active gas in two dimensions, we confirm the existence of an equation of state for periodic systems that depends on translational and rotational inertia in general. Confinement implies a strong polarization of the propulsion direction near a wall and an enhanced density, both of which increase with increasing rotational inertia. This affects the local stress tensor normal to the confining walls, leading to a breakdown of the equation of state. Yet the local stress in the bulk part of the confined systems is identical with that of the periodic system. Importantly, for both kinds of boundary conditions, the so-called swim stress is not included in the local stress tensor; thus, in general, the swim stress is not representative of the stress in systems of ABP+TRIs.

In this work, we investigate a cosmic inflation model based on a cosine-type potential with a negative cosmological constant. This model originates from a classical solution of the Wheeler-DeWitt equation. The equation of motion for the inflaton field can be solved analytically without relying on approximation schemes, such as the slow-roll conditions. The predictions of the spectral index, the tensor-to-scalar ratio, and the running spectral index are calculated and compared with experimental constraints from Planck Collaboration, Atacama Cosmology Telescope Collaboration (ACT), and Dark Energy Spectroscopic Instrument (DESI).

Merging galaxy clusters represent the ideal laboratory to test our understanding of the large scale structure formation history and the processes involved. While many merging clusters have been identified, only a limited number have been studied in detail through multi-wavelength analysis and dynamical reconstruction, this type of analysis being crucial to account for projection degeneracies. This work investigates the merger dynamics of the massive and complex cluster MACS0600 using high spatial, $\sim 15$ arcsec, radio and X-ray datasets in combination with ancillary optical data. We analyze the cluster morphology and the thermodynamic properties of the intracluster medium (ICM) through XMM-Newton and Chandra X-ray observations, and explore the non-thermal component via diffuse radio emission observed with Meerkat. We find a disturbed X-ray morphology with multiple substructures and a clear offset between the bulk of the radio emission and the X-ray peak. At the location of the X-ray peak, we detect a compact cool core surrounded by hotter gas and associated with a surface brightness discontinuity consistent with a cold front. The central region exhibits elevated temperatures and hosts most of the diffuse radio emission, suggesting merger-driven turbulence. Optical data further support a relative motion between the cool core and the main cluster along the line of sight. We conclude that MACS0600 is undergoing a merger in which a compact cool core has crossed the main, more massive cluster without being completely disrupted, while significantly perturbing the surrounding ICM.

Moiré superlattices in van der Waals heterostructures have recently gained significant attention as an intriguing platform for studying correlated electronic systems and exotic excitonic properties. Previous reports, however, focused on creating and modulating moiré heterostructures through interlayer twisting or lattice constant mismatches, limiting controls on symmetry of heterostructures. In this work, we show that strain significantly alters the geometry of moiré superlattices by breaking the C3 rotational symmetry. We realize strain-induced moiré superlattices by intentionally regulating interlayer strain in WSe2-MoSe2 heterostructures, which is manifested by linearly polarized interlayer exciton emission coupled to the strain direction. Furthermore, interlayer exciton diffusion was preferentially guided along the stretched moiré superlattice orientations over a wide spatial range, reflecting the strain-modified moiré potentials. Our work highlights strain tuning as a versatile tool for designing moiré superlattices and programming excitonic transport, which opens pathways for van der Waals logic and information processing devices.

The axial-vector form factor for the decay of pion $\pi^{+} \rightarrow \gamma + e^{+} + \nu_e$ is calculated by using the pseudovector coupling pion-nucleon interaction with the non-perturbative term. The self-energy is approximated by the lowest-order constant. The parameter is significant to improve the value of the form factor as well as the vector form factor in our previous study.

We introduce a Langevin formulation of Vicsek-like active particles in which orientations evolve through finite-rate relaxation toward the local mean direction, with alignment strength $J$ and rotational diffusivity $D_r$, thereby combining Vicsek-type local consensus with XY-like orientational dynamics. Using large-scale numerical simulations, we determine the nonequilibrium phase diagram as a function of activity and alignment rate. Increasing the alignment rate drives a sequence of transitions from a homogeneous isotropic state to polar bands, a cross-sea phase of intersecting bands, a homogeneous polar state, and ultimately a micro-clustered regime. The isotropic-to-polar transition is strongly first order, as evidenced by Binder cumulants and bimodal distributions of local polarization and density, indicating coexistence of gas-like and liquid-like regions. Near the onset of collective motion, band size increases with activity but depends non-monotonically on alignment rate. Further increasing the alignment rate drives the system through the cross-sea and homogeneous polar phases before enhanced density fluctuations lead to micro-clustering. Our results demonstrate that finite-time orientational relaxation acts as a control parameter that qualitatively restructures collective behavior in polar active matter.

We show that the transconductance of multilayer WSe$_2$ field-effect transistors serves as a direct electrical spectrometer of the intervalley relaxation time $\tau_{\rm iv}$, previously accessible only by ultrafast optical techniques. Extending an equilibrium valley-thermodynamics framework with a single relaxation equation for the $\Gamma$-valley carrier fraction $f_\Gamma(t)$, we predict three signatures: (i)~a Lorentzian transconductance $g_m(\omega)=g_{m,0}+g_{m,v}^0/(1+i\omega\tau_{\rm iv})$, whose imaginary part peaks at $\omega_c=\tau_{\rm iv}^{-1}$ with opposite signs for bilayer and trilayer; (ii)~a two-stage current transient after a gate step, exhibiting bilayer overshoot or trilayer undershoot; and (iii)~sweep-rate-proportional hysteresis whose gate-voltage profile and the layer-dependent transconductance sign reversal distinguish valley from trap-induced dynamics. All three signatures provide quantitative electrical access to $\tau_{\rm iv}$ with standard radio-frequency (rf) and direct-current (dc) instrumentation.

We respond to the comment by Matteo Giordano [1] on our article [2]. We find – and [1] itself acknowledges – that the proposed counterexamples intended to refute our argument violate a crucial assumption of QCD at high temperatures, namely that every gluonic observable is an analytic function of the squared quark mass, $m^2$. We further point out a technical mistake found in [1]. We conclude that the arguments presented in [1] are not valid.

The quasar main sequence, or Eigenvector 1 (EV1), describes the optical diversity of active galactic nuclei, with Narrow-Line Seyfert 1 (NLSy1) galaxies anchoring the high-accretion end. Recent discoveries of overly massive black holes in the early Universe highlight the need to study low-redshift, low-mass super-Eddington accretors as analogs of rapid black hole growth. We map 18,749 NLSy1 galaxies from the Dark Energy Spectroscopic Instrument Data Release 1 (DESI DR1) onto the EV1 plane. We compare the spectral properties of the DESI DR1 NLSy1 sample with the SDSS DR17 NLSy1 catalog, analyzed homogeneously. We extract key parameters, including the broad H-beta full width at half maximum (FWHM) and Fe II strength (R4570). To evaluate their accretion states, we derive single-epoch virial black hole masses using an Fe II strength-dependent scaling relation and an Eddington ratio-dependent fundamental plane, and test this choice with an Fe II-independent calibration. The DESI DR1 NLSy1 population occupies the extreme end of the EV1 parameter space, with strong Fe II emission (median R4570 = 0.96 +/- 0.35), similar to the SDSS sample (0.96 +/- 0.36). Under both calibrations, DESI and SDSS sources harbor low-mass black holes (median log black hole mass ~6.81-6.85). About 50% of both samples formally exceed the Eddington limit (log Eddington ratio > 0); this fraction drops to ~8-9% with the Fe II-independent calibration and is thus strongly calibration dependent. The unprecedented sensitivity of DESI has unveiled a large population of low-mass, highly accreting NLSy1 galaxies. Under the high-accretion interpretation, a geometrically thick inner disk would shield the outer broad-line region, naturally producing the observed strong Fe II emission. This sample provides a statistical dataset of low-redshift candidate super-Eddington accretors for understanding early-Universe black hole growth.

High-density nitrogen-vacancy (NV) ensembles are promising platforms for solid-state quantum sensing, but their performance is limited by dipolar interactions and inhomogeneous dephasing. Periodic decoupling sequences such as Waugh-Huber-Haeberlen (WAHUHA) can extend the observed stroboscopic decay time, but a longer fitted lifetime does not necessarily imply improved magnetic-field sensitivity. Here, we experimentally demonstrate this disconnect experimentally. WAHUHA increases the fitted stroboscopic decay time from $T_{2}^*$ of 0.9 $\mu$s to $T_{2,eff}^*$ of 31 $\mu$s, while producing little improvement in dc magnetic-field sensitivity. Using detuning-resolved stroboscopic spectroscopy and finite-pulse Floquet analysis, we show that the long-lived signal arises from phase wrapping and quasienergy branch folding of the one-cycle unitary. These effects reshape the stroboscopic spectrum, and the experimentally relevant folded branches exhibit a reduced local detuning-to-phase transduction slope, $d\Phi/d\Delta$, which governs the dc magnetic-field response. Our results demonstrate that, under periodic driving, an extended effective dephasing time does not necessarily translate into enhanced dc sensitivity and establish finite pulse Floquet analysis as a practical framework for evaluating coherence in spin ensembles.

Narrow-line Seyfert 1 (NLSy1) galaxies are peculiar active galactic nuclei (AGN) known to exhibit a variety of intriguing observational features from low-frequency radio waves to high-energy $\gamma$~rays. As of now, NLSy1 catalogs are primarily based on optical spectroscopic observations from the Sloan Digital Sky Survey (SDSS). Here we report, for the first time, a new catalog of NLSy1 galaxies using the high-quality optical spectroscopic observations made public in the first data release of the Dark Energy Spectroscopic Instrument (DESI). We performed a detailed spectral decomposition of more than 71,000 optical spectra of AGN not included in the SDSS catalog and located at $z<0.9$. From this sample, we identify 18749 objects as NLSy1 galaxies for the first time. We also supplement the NLSy1 catalog with a sample of broad-line Seyfert 1 galaxies. The NLSy1 galaxies identified in the DESI data tend to have slightly higher bolometric luminosities and lower black hole masses (though with large dispersions), leading to the higher Eddington ratios than those of the SDSS-NLSy1 sample matched in redshifts and absolute $B$-band magnitudes. Moreover, the fraction of DESI-NLSy1 galaxies detected in the radio, X-ray, and $\gamma$-ray catalogs was found to be lower than that of SDSS-NLSy1 sources. We conclude that deeper multiwavelength investigations of these enigmatic AGN will help unravel the low-luminosity end of the NLSy1 population. The catalog has been made available at https://www.ucm.es/blazars/seyfert and Zenodo https://doi.org/10.5281/zenodo.20484681.

Active microparticles with spatially organized multifunctionality could enable new forms of autonomous transport and chemical activity, yet creating such architectures within individual particles remains challenging. Here, we show that such complex functional architectures emerge spontaneously when multiple functional components (enzymes, nanoparticles, etc.) are introduced into evaporating multicomponent droplets undergoing liquid-liquid phase separation. Coupled Marangoni flows and interfacial dynamics drive the asymmetric localization of functional nanoparticles, positioning distinct functionalities on opposite sides of a microparticle in an architecture we term antipodal. This organization generates emergent magnetic anisotropy when magnetic nanoparticles are incorporated, enabling catalytically propelled motion parallel or antiparallel to a uniform magnetic field without an external chemical gradient. We also demonstrate enzyme-enzyme antipodal micromotors that combine weak chemotactic steering with strong propulsion driven by a spatially uniform chemical fuel, a strategy relevant to environments where chemical gradients are weak. Extensive theoretical modelling elucidates the underlying interplay of Marangoni flows and interfacial dynamics, providing a mechanistic basis for tunability. Our findings establish a route to spatially programmed active matter, in which functional architectures and directional capabilities emerge spontaneously through coupled hydrodynamic and interfacial dynamics.

We survey recent progress in the classification of hyperkähler and Hermitian gravitational instantons (i.e., complete noncompact 4 dimensional Ricci-flat manifolds with quadratic curvature decay), as well as the construction of non-Hermitian gravitational instantons via harmonic maps. We also present a list of open questions related to gravitational instantons.

We investigate the formation of light nuclei and hypernuclei in Au+Au collisions at $\sqrt{s_{NN}}=3~\mathrm{GeV}$ within a coalescence framework embedded in the microscopic N-body Parton-Hadron-Quantum-Molecular Dynamics (PHQMD) transport model. The Wigner phase-space distributions employed in the coalescence calculation are constructed from realistic $N$-body wave functions obtained by solving the Schrödinger equation in the hyperspherical harmonics formalism, providing a solid and parameter-free description of nuclear clusters and hypernuclei. By comparing calculated rapidity distributions with STAR data, we extract species-dependent coalescence times, revealing a non-universal formation pattern among different clusters. The resulting yields and kinematic distributions of light nuclei and hypernuclei are systematically analyzed and shown to be sensitive to the underlying wave-function structure and formation time. In addition, we explore cluster-nucleon formation channels for $A=4$ systems. These additional channels improve the description of ${}^{4}\mathrm{He}$ and ${}^{4}_{\Lambda}\mathrm{H}$ yields and help address the underestimation of $A=4$ cluster production in theoretical approaches. Finally, we provide predictions for heavier hypernuclei, including ${}^{5}_{\Lambda}\mathrm{He}$ and ${}^{5}_{\Lambda\Lambda}\mathrm{He}$, which are of interest for future experimental measurements.

The dynamics of the rolling tire govern structure-borne road noise below 500 Hz. Laser Doppler vibrometry (LDV) is the established laboratory reference for measuring rolling-tire modes. This paper presents a complementary approach that uses a single wireless tire cavity accelerometer (TCA) mounted on the inner liner and a once-per-revolution encoder on the drum of a tire-on-drum rig fitted with a cleat. Because the drum-to-tire diameter ratio (2.74) is non-integer, successive cleat impacts encounter the TCA at different circumferential positions. The TCA's contact-patch signature locates the sensor at each impact within approximately $1^\circ$, and grouping the impact responses by angular position synthesizes a 36-element virtual array from a single 128 s run. Covariance-driven stochastic subspace identification (SSI-COV) is applied using a consensus rule across multiple parameter settings, bootstrap resampling over impacts, and a correction for window-induced damping; the complete signal-processing chain is verified on synthetic data with known modes. For a slick 195/65R15 tire rolling at 30 km/h under a 1334 N load, ten modes between 46 and 193 Hz are robustly identified, exhibiting circumferential wavenumbers from 1 to 5, damping ratios of 2.1–4.2%, and strongly complex mode shapes, with three additional modes identified tentatively. The extracted modes follow the wavenumber ladder of a stationary modal test of the same tire. Requiring no optical access and capturing the full virtual array in a single run, the proposed method is well suited to treaded tires and on-road testing, at the expense of in-tire sensor installation.

This article presents a comprehensive analysis of two classes of quantum radars, including quantum direct-detection and quantum-entangled noise radars. In the first case, inspired by the well-established concept of single-photon LiDARs, we investigated the performance of single-photon radars, in which state-of-the-art single microwave-photon detectors are employed to enhance the detection sensitivity and enable the detection of weaker signals. We derived analytical expressions for the maximum detection range of both classes of quantum radars in terms of the Lambert W function, by considering all relevant system, target, and environmental parameters. Our formulation facilitates direct comparison of noise radars with direct-detection radars and suggests that a quantum-entangled noise radar can be regarded as an enhanced direct-detection radar with an effective threshold signal-to-noise ratio. Furthermore, we applied this framework to classical-correlated noise radars and defined the parameter range enhancement factor (REF) to quantify the superiority of quantum-entangled noise radars over their classical counterparts. Moreover, we introduced a rule-of-thumb for approximating the REF. We also examined the influence of limitations imposed by various microwave detection technologies. Our analysis shows that the conventional antennas limit the potential benefits of quantum-entangled noise radar systems. We also demonstrated that the optimal detection method for these radars is a microwave detector based on a quantum transducer combined with a single optical-photon detector. We showed that, with the current technology, implementing a quantum-entangled noise radar with the maximum detection range on the order of few kilometers is possible. Finally, we explored the potential applications of quantum-entangled noise radars.

Pierre-Nicolas Bertholon's 18th-century electrovegetometer was conceived to harness "atmospheric electricity" for plant growth, yet its physical capabilities have never been quantified within the context of today's understanding of the Earth's atmospheric electric system. This study addresses the lack of quantitative assessment of such historical "electroculture" device and its plausible influence on the near-canopy electrical environment. It aims to reinterpret Bertholon's apparatus using contemporary atmospheric electrodynamics, asking under which realistic fair-weather and storm-like conditions a purely passive collector-distributor could generate fields and ion fluxes of physical significance. A two-dimensional, quasi-steady ohmic model has been developed in which the atmosphere is a resistive column carrying the global conduction current, the metal structure is a floating conductor supported by leaky wooden insulators and space-charge and corona are excluded so that all results describe pre-onset upper bounds. The simulations show that in fair weather the single upper point and the lower multi-point crown of the electrovegetometer enhance the background field by two to three orders of magnitude, yet only within millimetric-centimetric regions around the tips and with total currents limited to the pA-nA/m^2 range. Under storm-like forcing, peak fields at the crown reach 100-1000 kV/m, approaching or exceeding empirical corona-onset thresholds, while remaining largely insensitive to uncertainties in apex angle or collector geometry as long as an elevated mast is present. These results make Bertholon's reports of luminous "aigrettes" physically plausible, but suggest that any fair-weather agronomic impact was subtle and highly localized and that modern "electroculture" claims require careful, coupled electrostatic and biological studies beyond the pre-corona regime.

We experimentally demonstrate the continuous-variable quantum approximate optimization algorithm (CV-QAOA) for multi-variable problems and multiple QAOA depths using a measurement-based CV quantum computing platform on a quad-rail lattice (QRL) cluster state. We propose a systematic method to map arbitrary quadratic cost functions onto the QRL architecture and examine the resulting construction in settings involving up to 100 modes. Using the programmable platform, we prepare the CV-QAOA ansatz and optimize the variational parameters via Bayesian optimization. We then investigate the performance on quadratic optimization problems and observe that increasing the depth from 1 to 2 improves performance, whereas further increases yield only limited gains. In contrast, numerical simulations under idealized conditions, assuming an infinite number of measurement shots and gradient-based optimization, indicate that the performance of CV-QAOA can improve with increasing depth, suggesting that the experimentally observed limitations primarily arise from noise accumulation and classical optimization challenges. This work provides an experimental demonstration of CV-QAOA on a programmable CV platform and establishes a foundation for future developments of variational quantum algorithms in CV systems.

Recently, experimental and theoretical quantum error correction methodology has seen remarkable breakthroughs. In particular, magic state cultivation has been shown to simplify magic-state preparation and make it feasible for near-term devices. However, recent research on magic state cultivation has focused primarily on the cultivation of $T\left| + \right>_L$. Only a few other magic state cultivation methods beyond $T\left| + \right>_L$ have been investigated. Here, we generalize phase kickback checks for magic states at arbitrary Clifford hierarchy levels in specific codes. We provide an example of cultivation of $\sqrt{T}\left| + \right>_L$ in the doubled color code and the corresponding escape strategy using lattice surgery from the color code to large rotated surface codes. Using state vector simulation for un-grown cultivation, we observe a strong consistence between $S\left| + \right>_L$ and $\sqrt{T}\left| + \right>_L$ cultivation's performance on the doubled color code. Finally, we discuss the application of the corresponding $\sqrt{T}\left| + \right>_L$ cultivation, incorporating the STAR architecture and $T$ gates, for early fault-tolerant quantum computing and its potential to shorten gate synthesis in the fully fault-tolerant quantum computing era.

This review traces the historical trajectory of electricity in agriculture, from the earliest observations of electrical phenomena to the emergence of cold plasmas. Looking back to Antiquity and then to the Enlightenment, it underlines Abbé Bertholon's 18th-century efforts to channel atmospheric electricity to stimulate crops, using devices such as the electro-végétomètre. Although these early electroculture experiments relied on neither quantitative dosimetry nor rigorous methodology, they foreshadowed the idea of a controlled transfer of electrical energy to plants. Then the review examines the historical development of galvanism, electrochemistry, and the physics of gaseous discharges throughout the 19th and 20th centuries, which collectively laid the foundations for contemporary cold-plasma technologies. In the 21st century, plasma agriculture has emerged as an interdisciplinary approach integrating electrical, chemical, radiative, thermal, and fluid-mechanical effects. Applications include seed treatment (preconditioning, seed priming), stimulation of plant growth, soil and water treatment, and decontamination of agri-food products. The review thus reassesses Abbé Bertholon's contributions as those of a methodological precursor and shows how his intuition of a "vivifying electricity" resonates with modern cold-plasma science. Finally, it argues that plasma agriculture can transform an Enlightenment intuition into a reproducible experimental framework for sustainable agriculture and food safety.

Classical nucleation theory describes the rate at which stable nuclei form within a metastable parent phase by crossing a free-energy barrier set by competing bulk and interfacial energies. In an elastic material, a pre-existing stress state modifies this barrier through an elastic contribution to the bulk driving force. This contribution is well characterized for linear elastic materials, but the corresponding finite-deformation result for soft solids remains less developed. The gap is computationally significant: in simulations that sample candidate nuclei throughout a stressed body, direct evaluation of the elastic contribution to free-energy change would require solving a new nonlinear elasticity boundary-value problem for each possible nucleus. Here, we derive an asymptotic expansion of the equilibrium elastic potential energy change for a hyperelastic body before and after formation of a small transformed region. The expansion is with respect to the amplitude of an isotropic transformation strain, while the pre-existing deformation and stress may be finite. At leading order, the elastic contribution to the formation energy is determined entirely by the known untransformed equilibrium fields, with additional terms accounting for stiffness contrast between the parent and transformed phases. Incorporating this into classical nucleation theory yields the stress-shifted transformation temperature, critical radius, and nucleation barrier. Representative results are shown for a compressible neo-Hookean solid under hydrostatic, uniaxial, and equibiaxial loading; tensile stresses promote nucleation and compressive stresses suppress it when transformation strain is expansive. Comparison with the corresponding linear-elastic result shows that finite-deformation effects can substantially change the predicted energy barrier at moderate stretches.

Confined active systems can sustain persistent vortical flows whose stability is strongly influenced by boundary conditions. At the individual level, active units generate internal stresses that drive spontaneous flows, which in turn advect and reorient the particles. This nonlinear coupling between active flow and orientational order is significantly mediated by the system's boundaries, where the specific slip condition governs how these internal stresses generate active flow then rearrange the local orientations. However, a quantitative understanding of how boundary slip dictates their dynamical stability remains lacking. Here, we study how the slip boundary condition controls the stability of a steady vortex state in a circularly confined active nematic system. Using a continuum model in a flow-dominated regime, we perform a linear stability analysis and derive an explicit criterion incorporating the slip velocity and flow-alignment coupling. We find that increasing slip velocity suppresses localized linear instabilities, thereby promoting the persistence of the steady vortex state. This reveals a relaxing the boundary friction actually stabilizes the macroscopic coherent structure by depressing flow induced reorientation that typically destroys single-vortex states. Our findings establish boundary slip as a nontrivial hydrodynamic control parameter for engineering stable active flows.

Helically twisted multilayers offer access to moiré physics beyond the single-superlattice paradigm, yet their correlated and topological transport properties remain largely unexplored in semiconductor moiré materials. Here we report magnetotransport measurements of helical trilayer WSe2, in which two coupled moiré patterns relax into a supermoiré landscape composed of inequivalent local topological domains with distinct electronic structures and unequal spatial areas. By electrostatic tuning, we identify a trilayer-hybridized regime where interactions and real-space reconstruction combine to generate a plethora of magnetic and topological states absent in the twisted bilayers. At moiré filling factor $\nu$ = -1, we observe a ferromagnetic insulating state that is robust against magnetic field and accompanied by a non-quantized anomalous Hall response ~-4 kOhms. This behaviour is consistent with a time-reversal-symmetry-breaking supermoiré Chern mosaic, in which the Hall response arises from the non-cancelling contributions of local domains with opposite Chern character arranged by the relaxed structure. Under strong magnetic fields, a symmetry-broken Chern insulating state (C = 1) emerges near $\nu$ = -2/3, displaying a much larger positive Hall response together with strongly enhanced longitudinal resistance, suggestive of field-reconstructed topological minibands and domain-boundary scattering. These results establish relaxed supermoiré semiconductor trilayers as a platform for spatially organized magnetism and topology beyond the bilayer limit.

We calculate the low-temperature superheating field $B_{\rm sh}$ of clean superconductors near the boundary between type-I and type-II superconductivity, with particular emphasis on Nb. Ginzburg–Landau theory is not applicable at low temperatures, while previous microscopic calculations have been limited to either the large-$\kappa$ regime or the dirty limit. The clean, low-$\kappa$ regime relevant to Nb has therefore remained unresolved. We solve the self-consistent nonlinear nonlocal Eilenberger problem for the Meissner state and then analyze its stability against small perturbations. For a Nb-like material with $\kappa_{\rm GL}=0.7$, we obtain $B_{\rm sh}\simeq 290\,{\rm mT}$ at $T/T_c=0.2$, using $B_{c0}\simeq 200\,{\rm mT}$. For a TESLA-shaped Nb accelerator cavity, this corresponds to an intrinsic Meissner-stability limit of about $67\,{\rm MV/m}$.

We investigate the magnetic properties of Li$_x$CoO$_2$ (x$\sim$0.9) using bulk magnetization, specific heat, nuclear magnetic resonance (NMR) and electron paramagnetic resonance (EPR) spectroscopy measurements. The dc magnetization, specific heat and NMR measurements, which probe the macroscopic response, indeed show that this compound partially undergoes an antiferromagnetic transition below $T_N \sim$ 10 K. In addition, we observed a weak ferromagnetic response, which gives rise to the history dependence in magnetization measurements at low fields and is observed at temperatures above room temperature. We propose that there are ferromagnetic clusters at high temperatures due to the formation of magnetic polarons out of doped holes. In EPR measurements performed at the $X$-band frequency, only a fraction of the total spins contribute and show Curie-like paramagnetic behavior as reflected in the temperature dependence of the EPR intensity. The temperature variation of the EPR spectra can be understood in the framework of the diffusion of magnetic polarons.

Non-Hermitian topological superconductors provide a setting in which point-gap topology, non-Hermitian skin effects, and Majorana zero modes are strongly intertwined. In this work, we adopt a coefficient-based approach for computing winding numbers and deriving analytical expressions for phase boundaries in one-dimensional non-Hermitian topological superconductors characterized by point-gap topology with $\mathbb{Z}$ invariants. We apply this approach to two non-Hermitian topological superconducting lattice models, with and without sublattice degrees of freedom, including longer-range hoppings, thereby accessing a much broader parameter space. These extensions generate higher-order polynomials and support phases with higher winding numbers, reflecting the underlying $\mathbb{Z}$ topology. We further clarify how a weak perturbation suppresses the non-Hermitian skin effect while preserving the sublattice-symmetry-protected invariant associated with Majorana zero modes. The predicted winding numbers are verified by open-boundary spectra, where one or multiple pairs of zero-energy boundary modes appear consistently with the bulk invariant. We also examine the stability of these modes against onsite disorder by examining the zero-mode energy, the bulk gap, and the inverse participation ratio. Our results provide a systematic and efficient route to constructing topological phase diagrams for higher-winding non-Hermitian topological superconductors.

Solar eruptions are powered by the release of magnetic energy stored in the lower solar atmosphere, but the pre-eruptive magnetic configuration of filament channels remains difficult to determine. A central question is whether this energy is stored in a pre-existing magnetic flux rope or in a sheared arcade that forms a flux rope only during eruption. Resolving this ambiguity is critical for identifying instability thresholds and eruption triggers, yet photosphere-based extrapolations often provide insufficient constraints on the three-dimensional coronal field. Here, we introduce a data-driven magnetic field extrapolation framework that combines photospheric and chromospheric vector magnetograms in a unified multi-height optimization, while accounting for variable chromospheric formation heights and the 180{\deg} azimuthal ambiguity. Tests with radiative magnetohydrodynamic simulations show that photosphere-only extrapolations can misidentify the pre-eruptive magnetic configuration, whereas chromospheric vector constraints recover the three-dimensional structure substantially more accurately. Applied to multi-line spectropolarimetric observations of an active region filament obtained with the Swedish Solar Telescope, the method reveals a reconstructed magnetic field consistent with a pre-eruptive flux-rope configuration. These results show that chromospheric vector magnetic measurements can provide decisive constraints on filament magnetic configuration and open a path toward diagnosing magnetic-energy storage and instability in eruptive solar active regions.

We investigate a harmonic interpretation of the hidden flavor coordinates (Q,G,C) introduced previously in a low-rank ternary description of the fermion mass spectrum. In this picture, the generation coordinate is associated with the odd harmonic sequence (1,3,5), allowing the fermion mass formula to be expressed in a compact harmonic form. The logarithmic mass spectrum then acquires an additive structure in which the hidden coordinates contribute directly to the observed hierarchy of fermion masses. We further argue that the scalar quantity (L=QG+C), which successfully organizes the fermion spectrum, does not uniquely identify a fermion state. This observation motivates the introduction of the full hidden-coordinate vector X=(Q,G,C) and a geometric interpretation of flavor in terms of distances, relative orientations, and antisymmetric invariants defined within the hidden-coordinate space. The harmonic framework also suggests a possible extension beyond the fermion sector. Combining the fermionic harmonic modes naturally generates the even sequence (2,4,6,8,10), which exhibits a suggestive correspondence with the electroweak and Higgs scales. While this correspondence remains speculative, it points toward a common harmonic structure underlying both fermionic and bosonic states. Although the framework is exploratory, it indicates that fermion masses, flavor organization, and bosonic excitations may represent different manifestations of a deeper hidden harmonic structure.

Devices based on the negative differential resistance effect in chromium doped V$_2$O$_3$ are considered to be promising as selector elements for use in emerging memory technologies, as well as for neuromorphic applications. It is shown by electrical measurements, that the switching effect is maintained for very thin films down to 5 nm, and even improved properties such as a low leakage current and an abrupt transition are observed. For these thicknesses, the behavior of crystalline and amorphous films becomes very similar; most strikingly, a forming step is required in both. Transmission electron microscopy reveals this to be likely due to a thin amorphous layer that forms at the interface to the TiN electrode. Elemental mapping further shows a complex distribution of the chromium dopants, as well as a diffusion of Ti into the layer from the electrode, which might be responsible for the improved properties.

This is a continuation of the paper [Commun. Theor. Phys., 77 (2025) 115006] on the nonlinearization of bilinear equations. The sine-Gordon type and nonlinear Schrödinger type bilinear equations are introduced by Jarmo Hietarinta during his search for integrable bilinear equations. In this paper, we provide a formulation to convert these two types of bilinear equations into nonlinear forms. In addition, the nonlinearization related to the equations involving the Hilbert transformations is also considered. Bell polynomials are employed in the nonlinearization and illustrative examples are provided.