Papers

We propose a controlled-Z gate scheme for Rydberg atoms based on level-crossing-free echoing rapid adiabatic population transfer. We design antisymmetric Rabi frequency pulses and symmetric detuning pulses, enabling the system to completely avoid level-crossing points throughout the evolution, and the dynamical phase is naturally eliminated by the time-reversal symmetry of the double-pulse sequence. We incorporate dissipative effects through the Lindblad master equation. The numerical simulation yields a two-qubit CZ gate fidelity of 0.9999. When the Rabi-frequency fluctuation is within $\pm 2\%$, and the detuning offset is within $\pm 1\%$, the fidelity can still remain above 0.999. Under the same dissipative model, the three-qubit CCZ gate achieves a fidelity of 0.999. When a single-parameter fluctuation does not exceed $\pm 3\%$, the fidelity is always higher than 0.997. Our scheme requires no laser phase jumps or fast switching operations. The zero-area pulse structure suppresses first-order intensity noise, and the symmetric double-pulse sequence avoids spatially resolved laser switching, making it suitable for parallel gate operations in large-scale neutral-atom arrays.

We introduce an operational measure of nonclassicality for qubit systems based on the violation of Kolmogorov consistency conditions in sequential measurements. In contrast to previous work by Milz et al.~\cite{Milz-2020}, who characterized classicality via NCGD maps, and Sakuldee et al.~\cite{Sakuldee-2022a, Sakuldee-2022b}, who studied quantum correlations under measurement disturbance, our witness explicitly quantifies nonclassicality in terms of the POVM unsharpness parameter $a_z$. For projective measurements on an initially diagonal state, the witness vanishes identically, showing that such measurements cannot reveal nonclassicality. However, by generalizing to positive operator-valued measures (POVMs), we find that non-projective measurements can reveal nonclassicality even for diagonal initial states. We derive explicit expressions for the witness for general initial states, including coherences, and show that its maximum value is $1/4$, which is a new result achieved for unbiased POVMs, maximal dephasing, and equal initial populations. Our results connect Kolmogorov consistency, Leggett-Garg inequalities, and POVMs, providing an experimentally accessible tool for detecting nonclassicality in qubit systems with potential applications in quantum technology certification.

Using patch-matrix-product methods, we study two reversible three-state interaction-round-a-face cellular automata introduced by Klobas and Prosen [J. Phys. A 55, 094003 (2022)] - the species-preserving and species-flipping rules - and a coherent quantum deformation interpolating between them. Within an explicit translationally invariant ansatz, the two classical rules share a one-parameter family of quasi-local conservation laws with an auxiliary-dimension-three realization. Every regular member is also the first centered logarithmic derivative of an analytic auxiliary-dimension-two family passing through the identity observable. On the closed span of this family and the three elementary local charges, the only nonzero Euler velocities are $\pm\sqrt{3/23}$. Consequently, $\sqrt{3/23}$ is a rigorous lower bound on the maximal Euler speed in any larger conserved sector. For the species-flipping rule, this value agrees with the reported extrapolated value $0.361$ of Klobas and Prosen, strongly supporting completeness of the known sound-active charges. The species-preserving rule admits, in addition, a staggered generating family whose logarithmic derivatives form an infinite tower of strictly local charges. In the quantum deformation, the same algebraic structures yield exact low-bond-dimension invariant states (scar candidates), exponentially long-lived quasi-local quasimodes, and diagonal quasi-local charges that produce a nonzero Mazur bound after projection away from the three elementary local charges.

This paper derives the second-order positive Burgers' equation from the standard Burgers' hierarchy to explore its complete integrability and exact analytical solutions. We construct this higher-order nonlinear evolution equation by systematically applying the recursion operator to the classical Burgers' equation. Expanding on this structural framework, we then derive the explicit third-order equation and use Complete Bell Polynomials to generalize the $n$-th order hierarchy. Through the Cole-Hopf transformation, the second-order nonlinear equation rigorously maps to the linear third-order dispersion equation. We establish complete integrability by explicitly formulating the scalar Lax pair (zero-curvature representation), which allows us to directly derive the associated differential and algebraic Darboux transformations. To systematically classify explicit stationary, time-dependent traveling wave, and self-similar profiles, we apply several techniques to the linear domain: separation of variables, the Hirota perturbation method, traveling wave reduction via the Complete Discrimination System for Polynomial Method (CDSPM), and Lie similarity reduction. Crucially, our analysis demonstrates the exact finite truncation of the Hirota perturbation series. We conclude by outlining how this equation impacts the theoretical understanding of fluid dynamics, nonlinear transport phenomena, and higher-order wave propagation.

The standard $\Lambda$ Cold Dark Matter ($\Lambda$CDM) model has achieved remarkable success in explaining the formation and evolution of cosmic structures on large scales, supported by a wide range of observations, including the cosmic microwave background, large-scale structure surveys, and galaxy clusters. However, discrepancies between theoretical predictions and observations on small scales, have motivated the exploration of alternative dark matter models, including the self-interacting dark matter (SIDM) scenario. This review provides an overview of the theoretical foundations of CDM structure formation, the small-scale challenges, and the solutions proposed within the SIDM framework. We summarize recent theoretical developments in the SIDM framework and discuss current observational constraints on the dark matter self-interaction cross-section with particular emphasis on galaxy clusters.

We present complex energy-resolved properties of quasi-periodic oscillations (QPOs) in the black hole X-ray binary GRS 1915+105 using an observation from the LAXPC instrument onboard AstroSat. Power density spectra (PDSs) are constructed in multiple energy bands and modeled with multi-Lorentzian components to investigate the energy dependence of QPO properties. The QPO frequency shows a modest increase with energy. Dynamic PDS analysis does not reveal clear evidence for time-dependent evolution of the QPO frequency, suggesting that the observed frequency shift is not primarily driven by temporal variability. We perform simultaneous fitting of energy-resolved PDSs and find that a model in which the QPO feature is described by two Lorentzian components provides a better fit. The two components exhibit different evolution in fractional root mean square amplitude as a function of energy. We further examine the phase-lag properties by simultaneously modeling the PDS and the real and imaginary parts of the cross-spectrum and find distinct phase-lag behavior for the two components. Overall, these results indicate that the apparent energy-dependent evolution of the QPO feature may be a result of the presence of more than one variability component.

Energy and charge transfer in condensed matter systems are often described in terms of quasiparticles. The order of accuracy of the results in terms of the electron-to-nucleus mass ratio $\epsilon$, an adiabatic small parameter, is usually not known. To quantify energy transfer with controlled accuracy in $\epsilon$, we use adiabatic perturbation theory to derive a formula for the rate of change of the nuclear kinetic energy. Applying a sequence of near-identity unitary transformations decouples the electronic and nuclear degrees of freedom to higher and higher order and produces an effective Hamiltonian. In the special case that the nuclei are treated classically, the energy transfer formula reduces to the usual formula for the rate of work done on a classical particle but the mass of the particle is enhanced by the factor $M_0^{-1}(M_0+\epsilon M_1)$, where $M_1$ is a nonadiabatic correction to the bare nuclear mass tensor $M_0$. Additional quantum geometric corrections appear at higher orders. Adiabatic perturbation theory is further used to incorporate, order-by-order in $\epsilon$, nonadiabatic transitions into linear response calculations. The nonadiabatic frequency-dependent conductivity and Drude weight of an electron-ion system are calculated.

The gapped Kondo effect describes the screening of an $S=\frac12$ impurity spin locally coupled via an antiferromagnetic exchange interaction to a conduction-electron system exhibiting a finite hard gap. Using a combination of a Lanczos transformation and a self-consistent configuration-interaction scheme, we numerically investigate the local phase diagram. Furthermore, we show that the different phases can be characterized by several topological invariants: the conventional momentum-space Chern number of the underlying two-dimensional host system, corresponding to a Chern insulator; the B-space Chern number, defined by coupling the impurity spin to a fictitious local magnetic field $\boldsymbol B$, in the limit $B \to 0$; and the S-space Chern number, defined for a classical impurity spin, i.e., a vector of fixed length. The classical-spin limit is obtained for $B \to \infty$. By varying the field strength, we can therefore continuously interpolate between quantum-impurity-spin and classical-impurity-spin Hamiltonians and investigate whether the corresponding phase diagrams are likewise continuously connected. The gapped underscreened Kondo effect is studied for an impurity spin $S>\frac12$ as well as in the classical-spin limit approached via $B \to \infty$ or $S \to \infty$. Different variants of scattering theory are employed to interpret the resulting phases. Finally, the gapped two-channel overscreened Kondo effect, realized by coupling a quantum impurity spin equally to the local electron spins of both orbitals within a unit cell, is shown to be characterized by spontaneous particle-hole symmetry breaking. This leads to a highly nontrivial quantum-classical phase diagram.

The study of magnetic chaos has traditionally focused on macroscopic variables under external driving. Here we demonstrate a new type of magnetic chaos, termed moiré magnetic chaos, associated with mesoscopic magnetic domain variables in twisted bilayer CrI3 without external driving. The domains are stabilized by a characteristic interlayer exchange frustration, which supplies the multiple dynamical degrees of freedom required for autonomous chaos. Through micromagnetic simulations, we show that relaxation toward moiré magnetic textures is extremely sensitive to minute local perturbations of the initial state, characterized by substantial finite-time Lyapunov exponents and a final-state sensitivity that persists over five decades of perturbation amplitude. Statistical analysis further reveals that the resulting domain configurations are stochastic and pairwise uncorrelated. Our results identify a form of microscopic, undriven chaos in twisted magnets that extends nonlinear magnetism beyond the conventional driven regime.

Young discs are expected to be significantly more massive than those observed at $>1$ Myr and it is at this earliest stage that planet formation likely begins. Such massive discs may be susceptible to the gravitational instability (GI), therefore we need to determine the disc and stellar properties for which the GI is active to understand its role in early disc evolution and planet formation. Prior work has been limited by model assumptions and inaccuracies due to the complex nature of the thermodynamics of protostellar discs so we now revisit this question using an improved method to approximate radiative cooling within hydrodynamics simulations. We have explored a wide parameter space, representative of young protostellar discs of 0.1 to 1 M$_{\odot}$ and include irradiation from the host star. The parameters for which discs form spirals and fragment were found to differ to those obtained from earlier simulations. The outer regions of discs with radii of 50 au may be susceptible to fragmentation, meaning that GI-driven planet formation is not restricted to only the most extended discs. The additional thermal support due to stellar irradiation increases the disc mass that remains stable against GI: discs may reach up to $\gtrsim 0.4$ M$_*$ without fragmenting, providing a considerable quantity of material for building planets. Large scale spiral arms only developed for $M_*\lesssim$ 0.3 M$_{\odot}$, except in the most compact discs. Furthermore, the long-lived spiral structures that form tend to be flocculent and compact, indicating that large-scale spiral arms should not be considered a typical outcome of GI.

Current methods for driving magnetic skyrmions predominantly translate ensembles as a whole, lacking single-particle selectivity. Here, we propose an "acoustic tweezer" that deterministically traps and routes individual skyrmions using spatially extended acoustic beams. We reveal that spatially confined longitudinal waves carry nontrivial phonon spin, inducing a magnetoelastic field whose chirality is locked to the acoustic spin texture. This generates polarity-selective radiation forces, distinct from conservative gradient forces, that attract skyrmions to local phonon spin maxima. Intersecting orthogonal beams create reconfigurable attractive points for adiabatic, deterministic manipulation. Our global-field-local-interaction paradigm establishes a non-destructive, on-chip route for high-precision topological spintronics.

The ability to control chirality in halide perovskites offers new opportunities for circularly polarized photonics, spin-selective electronics, and quantum information technologies. Chirality in halide perovskites is commonly achieved through chiral molecular building blocks or externally imposed photonic architectures. Although both approaches can generate strong chiroptical responses, many spin-dependent functionalities require structural symmetry breaking embedded within the material itself. Here we show that chirality can emerge directly during crystal growth. By combining glancing angle deposition with controlled substrate rotation, we generate highly textured PbI2 nanostructures with growth-controlled crystallographic torsion. X-ray texture analysis reveals that substrate rotation progressively rotates the crystal orientation during growth while preserving the c-axis orientation, resulting in a twisted texture with giant and tuneable chiroptical responses, including ellipticities of 19{\deg} and absorption dissymmetry factors approaching 0.6. The chirality programmed during growth is transferred through vapour-phase conversion into multiple halide perovskite compositions, resulting in circularly polarized luminescence with glum values up to 0.23. These findings establish growth-controlled crystallographic torsion as a previously unexplored origin of chirality in halide perovskites.

From fluid flow and transport to collective dynamics, numerical simulation of nonlinear partial differential equations underpins modern scientific computing. Extending this capability to quantum computers remains a longstanding challenge because nonlinear and non-Hermitian evolution is fundamentally incompatible with conventional Hamiltonian-based quantum simulation. Here we experimentally realize the time evolution of nonlinear fluid dynamics on a quantum processor using a hybrid variational framework for the viscous and inviscid Burgers equations. Our approach directly encodes the nonlinear dynamics into a variational optimization procedure, avoiding the enlarged linear embeddings and truncation overhead associated with Carleman linearization-based quantum algorithms. We further demonstrate convection-dominated dynamics corresponding to Reynolds numbers of order $10^2$. We encode the governing evolution into parametrized quantum circuits and iteratively reconstruct the time-dependent field through quantum-classical optimization. By introducing a zero-noise extrapolation method without additional circuit-folding overhead, we accurately execute deep error-circuits with entangling-gate counts beyond those typical of Hadamard test circuits. We accurately reconstruct the time evolution across multiple timesteps despite hardware noise and finite device coherence. Our results constitute, to our knowledge, the first experimental realization of nonlinear time propagation on a quantum processor, extending quantum simulation beyond predominantly linear settings and establishing a route toward quantum computation for nonlinear continuum dynamics.

Boronization, where boron is deposited onto tungsten surfaces, is a key technique to reduce plasma contamination, such as oxygen in Tokamak fusion reactors. The exact interaction between the boron atoms and the tungsten surface, and the effect of the harsh environment on these surfaces are however not fully understood, partially due to the lack of accurate atomistic simulations and interatomic potentials. Here, we develop a machine-learned interatomic potential for sputtering studies of W-B structures and deposition of boron onto tungsten surfaces. The machine-learned potential is trained to density functional theory data and allows accurate large-scale molecular dynamics simulations. Our aim is to understand how boron behaves when deposited on tungsten and how tungsten and boron are sputtered under irradiation. We observe that both the surface configuration/orientation and the surface composition affect the sputtering, and that depositing boron onto tungsten surfaces produces a dense boron layer. The developed potential shows good accuracy for both surface and bulk properties and can be used for simulations of mixed W and B systems.

Dual-comb spectroscopy, constructed from two frequency combs with slightly different repetition frequencies, enables real-time and high-precision measurements without mechanical scanning. In the terahertz spectral range, dual-comb techniques provide a powerful tool for high-resolution and rapid spectroscopy. Quantum cascade lasers (QCLs), owing to their compact footprint and favorable size, weight, and power, have emerged as promising sources for THz dual-comb systems. In QCL frequency combs, the repetition frequency generated through intrinsic four-wave mixing is typically equal to the cavity round-trip frequency, corresponding to the fundamental comb. Although this repetition frequency can be tuned via current and temperature control, the accessible tuning range remains limited. Recently, harmonic frequency combs, whose repetition frequencies are integer multiples of the cavity round-trip frequency, have attracted increasing attention, offering enhanced single-line signal-to-noise ratios and providing direct insight into the strong nonlinearity of QCLs. Here, we demonstrate a reconfigurable multi-harmonic dual-comb system realized on a single self-detected THz QCL platform. By precisely controlling the driving current and thermal conditions, we achieve and switch between multiple dual-comb configurations, including fundamental-fundamental, fundamental-second-harmonic, second-harmonic-second-harmonic, and second-harmonic-third-harmonic dual-combs. These results establish harmonic order as an additional degree of freedom for dual-comb operation within a single laser system. The demonstrated platform enables high-resolution and high-sensitivity measurements while significantly simplifying the system architecture. This reconfigurable multi-band dual-comb approach based on a single QCL opens new opportunities for compact THz spectroscopy and frequency metrology.

Complete sets of graphical rewrite rules enable fully graphical reasoning about quantum computations and have been an area of active research for more than a decade. Many recent applications of the ZX-calculus have made use of the close correspondence between ZX-diagrams and computations in the one-way model of measurement-based quantum computation. In this model, various kinds of flow properties ensure deterministic implementability; for ZX-diagrams, these same properties allow efficient translation into quantum circuits (a problem that is known to be #P-hard in general). Therefore, flow-preserving ZX-calculus rewrite rules are of strong interest. Here, we extend the set of flow-preserving rules appearing in the literature with a few new rules and extensions of existing rules. We then show that the resulting rule set is complete for all flow-preserving translations between ZX-diagrams of appropriate form. The proof employs a manifestly flow-preserving equivalent of circuit extraction, where a diagram with gflow is transformed, using only flow-preserving rewrite rules, into a diagram with causal flow.

In this work we identify and photodynamically analyze TIC 433545934, the very first doubly eclipsing 2+2-type quadruple stellar system, which shows outer eclipses, too. One such outer eclipse was discovered with TESS, which triggered a special interest in this system. Most of the data for this study come from TESS observations, but we also obtained supplemental ground-based photometric measurements for this quadruple system. The eclipse timing variation curves extracted from the TESS and ground-based follow-up data, the photometric light curves, and the spectral energy distribution are combined in a complex photodynamical analysis to yield the stellar and orbital parameters of this dynamically interesting system. The periods of the two inner, eclipsing binaries were found to be $P_A=2.07$d and $P_B=1.41$d, while the outer period is $P_{AB}=224.5$d. The outer period alone makes this system the fifth most compact known 2+2-type quadruple. Moreover, what really makes TIC 433545934 unique is that TESS observed a triple-dipped extra eclipsing event when the stars of binary B eclipsed the two components of binary A. We identified similar extra eclipsing events in the archival, ground-based data of ASAS-SN and ATLAS, as well. We found, however, that these extra events occur only once during an outer revolution, that is, binary A does not eclipse the stars of binary B. This is in accord with our finding that the outer eccentricity is quite high, being $e_{AB}=0.62$. Our analysis reveals that binary A consists of two quite similar, but slightly evolved late A-type stars ($q_A=0.92$), while in the case of binary B, the primary star, whose mass is between the masses of the two stars of binary A, is quite dominant, with $q_B=0.60$. The system was found to be substantially flat, with mutual inclination angles below $\approx2\degr$.

Conventional nanophotonic color routers are typically optimized under idealized, normal plane waves. However, this standard assumption fails in real-world imaging-system environments, where structures are illuminated by converging light cones and field-dependent chief-ray angles. Here, we present an imaging-system-aware, end-to-end inverse-design framework that directly maximizes the mutual imaging information $\Iimg$ preserved by a single-layer silicon nitride color router under realistic pupil illumination. By analytically embedding the optimal reconstruction decoder directly inside the gradient loop, we co-design the optical nanostructures and the digital recovery pipeline. To scale this approach across a full sensor, we exploit the $D_4$ symmetry of the square pixel lattice, tiling $48$ distinct sensor-field regions using only six unique lithographic masks. Our optimized router is predicted to collect $2.8\times$ more photoelectrons than a conventional color-filter array. Consequently, under low-light conditions, below a green-site signal-to-noise ratio of $13.7$~dB, the color router preserves superior image information compared to the color-filter array; evaluated from its measured routing fractions together with the modeled throughput, the fabricated device reproduces this crossover at $11.1^{+2.1}_{-2.3}$~dB. This marks the first experimental demonstration, from measured routing and a modeled throughput, of a single-layer nanophotonic color router achieving a performance crossover against the color-filter array. These results establish that next-generation flat optics must shift from isolated device efficiency toward system-level co-design optimized under physical imaging-system-pupil geometry.

Nonequilibrium membrane pattern formation is studied using meshless membrane simulation. Bound proteins are considered to have two states that generate different membrane spontaneous curvatures. Protein binding and unbinding occur cyclically owing to chemical potential differences, as an off-lattice active Potts model. It is found that this cyclic binding/unbinding can induce blinking domains, with oscillating size: convex domains of the proteins with a higher spontaneous curvature grow, and subsequently, the proteins change to the other state with a lower spontaneous curvature, resulting in domain shrinkage. These processes repeat. In thermal equilibrium, hexagonal convex domains are formed by the competition between bending and surface tension energies, so that they are stably formed only under positive surface tension. However, blinking domains can form even in tensionless membranes.

In this paper, we travel through an unknown territory of dromions, to unearth and show the new properties/attributes of dromions which have never been brought to the fore since they were first discovered by Boiti etal [1]. These new attributes are brought out by investigating a generalized (2+1) dimensional Nonlinear Schrodinger (NLS) equation by exploiting Truncated Painleve approach. The signatures that can be attributed to dromions include existence of firewall and reflection at the boundary, uneven distribution of energy among different bound states, amplitude dependence on adjacent dromions, etc. We have corroborated the main analytical results with numerical simulations also. We categorically state that these properties are universal and can be extracted in any (2+1) dimensional nonlinear partial differential equation. We do believe that these properties which shed more light on the behaviour of dromions may have wider repercussions in nonlinear optics, Bose-Einstein condensates and plasma physics.

The high-frequency sensitivity of laser-interferometric gravitational-wave detectors is limited by quantum shot noise. Increasing the circulating optical power reduces shot noise, but is constrained by thermal effects and optomechanical instabilities. We propose cyclic-quadrature intracavity signal amplification, in which an optical parametric amplifier (OPA) inside a detuned signal-recycling cavity is used as a phase-sensitive amplifier of the gravitational-wave signal quadrature. By detuning the signal-recycling cavity for $\pi$/4, the optical quadratures rotate by $\pi$/2 on each round trip, so a signal generated in the phase quadrature appears in the readout phase quadrature only after odd-numbered passes through the OPA. Successive contributions to the readout phase quadrature, which are separated by two round trips, have alternating signs, making this two-round-trip evolution anti-resonant. During each two-round-trip cycle, however, the same field experiences one amplification and one deamplification, so neither vacuum squeezing nor parametric gain accumulates. Despite the destructive interference between signal contributions separated by two round trips, the OPA increases the signal component extracted through the output coupler, thereby improving the signal-to-noise ratio. When the OPA gain is sufficiently large, the response approaches that of an interferometer with an effective power enhancement of $1/\tau^2$, where $\tau$ is the amplitude transmissivity of the quadrature-rotation mirror that forms the amplifier cavity. We apply the proposed scheme to a current gravitational-wave detector with a near-future upgrade and show that it improves the quantum-noise-limited sensitivity over a broad frequency range extending into the kilohertz band.

Luminous fast blue optical transients (LFBOTs) emit from x-ray to radio wavelengths, epitomised by the discovery of AT 2018cow in a host galaxy at 65 Mpc. In the following eight years eleven more have been found, at redshifts $0.075 \lesssim z \lesssim0.34$, plus one identified retrospectively from 2016. Here we present the discovery of AT 2024qfm, classified as an LFBOT in a host galaxy at $z = 0.2267 \pm 0.0002$. Its ultraviolet-to-optical luminosity and rapid 13 day fade closely match AT 2018cow. We describe how the transient was identified in the Zwicky Transient Facility alert stream using a custom filter in the Lasair broker that flags flux gradients over time. Another LFBOT candidate was identified with the same methodology (AT 2024kth). The physical origin of LFBOTs remains debated with no firm consensus, and further progress requires more discoveries, host-galaxy characterisation, and multi-wavelength analysis to constrain theory. We discuss this discovery in the context of Rubin Observatory's Legacy Survey of Space and Time (LSST), whose sensitivity will increase the effective LFBOT survey volume tenfold relative to ZTF, out to $z \lesssim 0.6$, and show that our FastFinder filter could recover such events. We highlight the challenge of detecting their fast evolution with sufficiently low latency to trigger multi-wavelength follow-up that can constrain theoretical models.

We present the first results of SNIFFLES, an ongoing observational programme to characterise intended emission, unwanted emission, and unintended radiation from NGSO systems across common radio astronomy receiver bands from 1-26 GHz (L, S, C, X, and K bands). Using the Australian 22 metre Mopra radio telescope near Coonabarabran, New South Wales, with followup observations from a single dish of the ATCA interferometer and its new BIGCAT backend, we conducted 4629 tracked observations of satellites from four NGSO constellations (Starlink, OneWeb, Amazon Leo, and Guowang), amounting to 375.9 hours of telescope time. Satellite identification was confirmed by correlating detected Doppler shifts with predicted ephemerides. We detected 2345 instances of intended emission, unwanted emission, and unintended radiation at 300+ unique frequencies from three of the four systems. The detections span all three interference classes affecting radio astronomy: (1) intended emission (including DTD), (2) unwanted emission (OOBE, including up to the fourth harmonic of the Starlink DTD signal at approximately 2.6 GHz, with the fourth harmonic detected near 10.5 GHz), and (3) unintended radiation from satellite platform electronics. Several detections fall within primary radio astronomy allocations, including 1613.19 MHz within the protected OH line band, and at 2690.76 MHz and 2700 MHz. At 2700 MHz, unintended radiation was detected in 76.9 percent of all observations of the relevant satellite version. ATCA followup measurements confirm flux densities up to eleven orders of magnitude brighter than typical astronomical sources, well in excess of levels that saturate radio astronomy receivers.

In previous work, we introduced a semi-analytical method for computing time-domain solutions of linearized Vlasov problems. Rather than representing the plasma response as a sum of residues associated with Landau poles, the method constructs a regularized frequency-domain response spectrum that is subsequently inverted numerically. Explicit applications have so far been limited to unmagnetized plasmas. In this work, we extend the construction to plasmas with a uniform background magnetic field and a Maxwellian equilibrium distribution. We apply the resulting formulation to the electrostatic ion-Bernstein density response of a plasma with kinetic ions and adiabatic electrons, and provide error estimates for truncating both the spectral integration domain and the cyclotron-harmonic expansion. The solution serves as a time-domain reference for damped finite-$k_\parallel$ regimes, in which dispersion-relation roots alone are insufficient for pointwise-in-time verification of simulation codes. Finally, we indicate how the framework can be extended to fully electromagnetic problems.

In this article we analyze the effects of a finite temperature equation of state on the equilibrium structure of white dwarfs in massive Brans-Dicke theory as well as the symmetron and dilaton screening mechanisms. We compute and present the numerically obtained mass-radius relation, effective gravitational constant as well as radial profiles of the scalar field, pressure and metric within the star. We show that assuming a non-zero temperature effectively results in a larger radius while leaving the total mass of the star essentially unchanged, and discuss the interplay between the effective gravitational constant, central density, and radius of the star.

Satellite precipitation products such as IMERG exhibit biases that vary with terrain, season, and precipitation regime, leaving the applicability boundaries of machine learning correction unclear. This study proposes the Terrain-Moisture-Intensity (TMI) framework, centered on mechanism purity, extending the correction problem from purely algorithmic optimization to physical consistency diagnosis. A proof-of-concept study in Hunan Province employs IMERG V07, SRTM DEM, and ERA5 variables (tcwv, u10, v10). Ablation results indicate that, under the conditions of this study, terrain-moisture relationships are predominantly additive: RF-Full yields merely +0.001 R^2 gain over LR-Full, while bias rises to 1.282 mm d^-1; MAE decreases by approximately 14%, reflecting a trade-off between tail-fitting improvement and mean shift. SHAP diagnostics identify three categories of boundaries. Spatially, Central Hunan exhibits significant degradation (R^2=0.133) despite strong variable activation, consistent with mechanism fragmentation induced by mixed terrain. Temporally, u10 undergoes directional reversal between summer and spring (+0.096 to -0.156), presenting "silent failure." Extreme precipitation (>=50 mm d^-1) approximates a mechanism saturation frontier rather than isolated out-of-distribution samples, with DEM showing the largest relative amplification in SHAP disorder (+150%). The results demonstrate that machine learning correction performance is primarily constrained by mechanism purity. A pre-registered cross-regional test (Hunan, Guangxi, Guangdong) confirms this screening capability out of sample: a priori coherence proxies predict correction efficiency with a mean absolute error of 2.6 percentage points, while the transfer-versus-retraining contrast separates mechanism mismatch (coastal Guangdong) from portability (Guangxi), establishing the framework as a validated applicability screen.

Molecular orientation within ultrathin films is a critical factor in controlling their optical and electronic properties for surface-based photonics and optoelectronics. In this study, we examine two amphiphilic boron-dipyrromethene (BODIPY) derivatives, distinguished by the number of hydrophobic alkyl chains, and investigate their organization and optical response using Langmuir–Blodgett deposition. The spatial and orientational distribution of molecules at the nanoscale is determined by combining hyperspectral imaging, photoluminescence radiation pattern analysis, and incidence-angle-resolved absorption spectroscopy. We evidence, both experimentally and based on a new and original theoretical model, the formation of organized monolayers exhibiting either in-plane or perpendicular transition dipole alignment, depending on the molecular symmetry. These results underscore the deep impact of molecular engineering on supramolecular order and anisotropic optical properties at interfaces, providing a robust strategy for the design of functional thin films down to the monolayer level for advanced optical devices.

Efficient detection of single microwave photons is a key capability for emerging quantum technologies. Yet, it remains far less developed than its optical domain counterpart. Realizing detectors that simultaneously achieve high efficiency, low dark counts, and continuous operation has proved challenging. Existing detectors operate cyclically, forcing a trade-off between efficiency and duty cycle. Here, we demonstrate a continuously operated microwave single-photon detector based on a superconducting artificial molecule. In our scheme, an incoming photon is captured by a bright state of the molecule and then transferred to a long-lived dark state via a driven-dissipative process. Photon “clicks” are revealed as quantum jumps in the continuously monitored dark state. We observe a cyclic detection efficiency of $0.73$, and a continuous detection efficiency of $0.47$ over a $5\,\mathrm{MHz}$ instantaneous bandwidth, with a $1\,\mu\mathrm{s}$ temporal resolution and a $15\,\mu\mathrm{s}$ dead time. By overcoming the trade-off between efficiency and duty cycle, this approach establishes continuous microwave photon detection for quantum sensing, quantum thermodynamics, and fundamental physics.

Spin-current vorticity (SCV) can generate the linear magnetic spin Hall effect [\href{https://doi.org/10.1038/s41586-018-0853-0}{Nature 565, 627 (2019)}], yet its role in nonlinear spin Hall transport has been much less explored. Here, we show that, under a dc electric field, SCV can deflect optically excited electrons to drive a dissipationless photovoltaic spin Hall effect (PSHE), in which optical excitation by circularly and linearly polarized light is governed by the Berry curvature and quantum metric, respectively. Because the Berry curvature is $\mathcal{T}$-odd whereas the quantum metric is $\mathcal{T}$-even, their respective combinations with the $\mathcal{T}$-odd SCV give rise to $\mathcal{T}$-even and $\mathcal{T}$-odd PSHEs, where $\mathcal{T}$ denotes time-reversal symmetry. Remarkably, we find that the spin current of the $\mathcal{T}$-even PSHE can be reversed by switching the light helicity, as illustrated in monolayer WTe$_2$. By contrast, the $\mathcal{T}$-odd PSHE in altermagnets changes sign upon Néel-vector reversal, as demonstrated in a $d$-wave altermagnetic model. Beyond the PSHE, we show that the SCV dipole governs both the Drude and intrinsic nonlinear spin Hall effects proposed recently. Our results reveal two switchable spin Hall mechanisms and establish SCV as a unifying concept for understanding dissipationless nonlinear spin Hall transport.

We investigate how silicon vacancies modify the elastic response and mechanical stability of cubic 3C-SiC. Our approach employs path-integral molecular dynamics simulations, including the classical-nuclei limit, based on an efficient tight-binding Hamiltonian, whose accuracy is validated against density-functional-theory calculations. This framework enables a quantitative assessment of nuclear quantum effects arising from zero-point motion. Across a broad range of temperatures and hydrostatic pressures, spanning both tensile and compressive regimes, silicon vacancies are found to substantially renormalize the elastic constants $C_{11}$, $C_{12}$, and $C_{44}$, as well as the bulk modulus, relative to the defect-free crystal. Inclusion of nuclear quantum motion produces an additional softening of these elastic properties, particularly at low temperatures, demonstrating that quantum fluctuations make a measurable contribution to the mechanical response of defective SiC. Vacancies also affect the mechanical stability domain of 3C-SiC, lowering the maximum sustainable tensile pressure by approximately 4 GPa for a defect concentration of 0.016 per lattice site. These results reveal an interplay between point defects and quantum lattice fluctuations in determining the elastic behavior of SiC, providing microscopic insight relevant for both extreme-environment structural applications and defect-based quantum technologies.