Quantum Physics
Julio I. de Vicente
Local operations assisted by classical communication (LOCC) play a fundamental role in the resource-theoretic formulation of
entanglement theory inducing an operationally meaningful ordering in the set of entangled states. The particular class within LOCC of local
unitary (LU) transformations is obviously closed under inversion. Thus, LU-equivalent states are interconvertible by LOCC and have therefore the same
entanglement. For this reason LU-equivalence has been thoroughly studied in the context of
entanglement theory. However, as I note here with a simple example, the converse is not true: there exist entangled states that are interconvertible by LOCC but which are not LU-equivalent. This motivates studying under which conditions LOCC interconvertibility is characterized by LU-equivalence. I provide a sufficient condition for this to hold. When one considers multipartite states with full
entanglement dimensionality (as quantified by the Schmidt number vector) LOCC interconvertibility can only hold under LU-equivalence.
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High Energy Physics (Phenomenology)
Discriminating baryonium and final-state-interaction interpretations of $X(2356)$
Bing-Dong Wan and Sheng-Qi Zhang
We revisit the $X(2356)$ enhancement observed by BESIII in $e^+e^-\to\Lambda\bar\Lambda\eta$ from the viewpoint of near-threshold dynamics. Motivated by the possibility of light $\Lambda\bar\Lambda$ baryonium, we compare this interpretation with final-state-interaction (FSI) explanations within a minimal FSI-dressed pole framework. Fits of the pure-FSI, baryonium-like-pole, and mixed pole–continuum scenarios to the digitized BESIII spectrum identify the energy-dependent FSI description as providing the best balance between fit quality and model complexity. The extracted pole positions depend strongly on the amplitude parametrization, demonstrating the sensitivity of the baryonium interpretation to the treatment of the continuum. We discuss how decay channels,
spin observables, and partner searches can provide complementary constraints on the dynamics underlying the enhancement.
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Soft Condensed Matter
Phase Separation in a system of Brownian inertial rotors
Lucio Mauro Carenza, Pasquale Digregorio, Massimiliano Semeraro et al. (+3 more)
We uncover an emergent phase separation in a system of inertial dumbbells put into persistent rotation by a constant applied torque, breaking
chiral symmetry, while interacting with each other through repulsive hard-core interactions. We numerically determine the phase diagram of the model, showing that there exists a binodal and a spinodal region where the system separates into a dense
liquid and an ordered phase, which we identify as hexatic. An analysis of the system pressure unveils that the mechanism underlying the phase separation is heavily controlled by inertia. Locally injected kinetic energy is steadily stored into the system in a way that depends on density and that, at large inertia, results in a hot dilute and cool dense state, leading to a generically unstable homogeneous phase. The interplay between dumbbells' arrangement into clusters and
chiral forces produces a spontaneous rigid rotation of the clusters around their centers of mass.
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All authors Lucio Mauro Carenza, Pasquale Digregorio, Massimiliano Semeraro, Antonio Suma, Ignacio Pagonabarraga, Giuseppe Gonnella
Materials Science
Orbital angular momentum accumulation in SrVO3 thin films
Julien Brehin, Montserrat X. Aguilar-Pujol, Dongwook Go et al. (+3 more)
Orbital transport in light transition metals has emerged as a promising route toward angular-momentum electronics, with Hanle magnetoresistance (HMR) providing a direct electrical probe of the orbital
Hall effect (OHE) in non-
magnetic conductors. Here we report magnetoresistance signatures consistent with orbital HMR in epitaxial SrVO$*3$ (SVO), a narrow-band $d^1$
oxide grown on (001)-oriented (LaAlO$*3$)$*{0.3}$(Sr$*2$TaAlO$*6$)$*{0.7}$ substrates. In films of different thickness and longitudinal resistivity, field-dependent measurements reveal a reproducible positive, even-in-field, and approximately quadratic $\Delta\rho*{x-y}$ response, as expected for HMR. Angular measurements characterize the corresponding magnetoresistance anisotropy and reveal an additional non-Hanle contribution. Density functional theory (DFT) calculations yield an intrinsic orbital
Hall conductivity $\sigma*{\mathrm{OH}}^{\mathrm{DFT}} = 390,(\hbar/e),\Omega^{-1}\mathrm{cm}^{-1}$ and a
spin Hall conductivity $\sigma_{\mathrm{SH}}^{\mathrm{DFT}} = -12,(\hbar/e),\Omega^{-1}\mathrm{cm}^{-1}$ at the
Fermi level, corresponding to $|\sigma_{\mathrm{OH}}^{\mathrm{DFT}}/\sigma_{\mathrm{SH}}^{\mathrm{DFT}}| \approx 33$, thus indicating a predominantly orbital response. Using the diffusive HMR framework with $\lambda_{\mathrm{OD}} = 2$ nm as a reference value, the 20.8 nm film gives conservative saturation-limit lower-bound (LB) estimates $\theta_{\mathrm{OH,LB}} = 0.0144 \pm 0.0004$ and $\sigma_{\mathrm{OH,LB}} = (460 \pm 11),(\hbar/e),\Omega^{-1}\mathrm{cm}^{-1}$, comparable to the DFT value. Across the series, lower-bound estimates obtained with the same $\lambda_{\mathrm{OD}}$ increase overall with longitudinal conductivity. These results suggest that narrow-band $d^1$ metallic
oxides are a promising platform for orbital transport.
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All authors Julien Brehin, Montserrat X. Aguilar-Pujol, Dongwook Go, F. Casanova, J. Fontcuberta, E. Longo
Instrumentation and Methods for Astrophysics
Status and performance of the Asgard/NOTT cold nulling camera
P. Chingaipe, G. Medgyesi, A. Mazzoli et al. (+25 more)
Long-baseline nulling interferometry suppresses the on-axis light of a
star, enabling high-contrast observations of faint circumstellar emission and
exoplanets at high angular resolution. The Nulling Observations of
dusT and
PlaneTs (NOTT) instrument is the L'-band nulling interferometer of the Asgard instrument suite and will be the first nuller installed at the Very Large
Telescope Interferometer (VLTI). Its main scientific goals are to characterise hot/warm exozodiacal
dust and young Jupiter-like
exoplanets at close (<10 AU) orbital separations, where indirect detection methods are most sensitive. NOTT uses a four-
telescope integrated-optics photonic beam combiner operating over 3.5-4.0 micrometres. The photonic chip produces photometric, bright, and nulled outputs that are polarization-split, spectrally dispersed, and imaged onto a 5-micrometre-cutoff HAWAII-2RG detector by the NOTT cold nulling camera. The cold optical assembly includes the photonic-chip interface, injection optics, collimator, Wollaston prism, dispersive element, imager, and cryogenic detector stage. The mechanical implementation is designed for operation near 90 K using aluminium support structures, spring-loaded optical mounts, and cryogenic-compatible mechanisms to preserve
alignment during cooldown. We present the current status and performance of the NOTT cold nulling camera and cryostat assembly. The system is undergoing assembly, integration, and verification to validate thermal stability, detector operation,
vacuum performance, and opto-mechanical repeatability. Initial cryogenic tests have demonstrated operation near 100 K for the cold optics and 30 K for the detector, cryogenic validation of the filter wheel, and a
vacuum pressure of 8 x 10^-8 mbar. These activities represent a key step toward deploying NOTT as the first nulling interferometer at the VLTI.
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All authors P. Chingaipe, G. Medgyesi, A. Mazzoli, E. Bouzerand, R. Laugier, P. Abraham, C. Dandumont, D. Defrère, A. Glauser, G. Garreau, M. Ireland, A.P. Joo, J. Loicq, M-A. Martinod, K. Missiaen, M. Montoya, J. Morren, G. Raskin, M. Salman, W. Schofield, W. Verstraeten, S. Ertel, T. A. Stuber, J. P. Scott, S. Kraus, F. Martinache, X. Haubois, N. Schuhler
Materials Science
Single Best Fits Can Be Misleading: Resolving Common Trapping Signatures across FA–Cs Perovskites
Maxim Simmonds, Katarzyna Pydzińska-Białek, Thomas C. Rossi et al. (+6 more)
Identifying defects responsible for non-radiative recombination in metal-halide perovskites remains challenging, with no common defect signatures established across compositions. Here, we combine fluence-dependent time-resolved photoluminescence, full Shockley–Read–
Hall modelling and
Bayesian posterior inference across an FA$_{1-x}$Cs$_x$PbI$_3$ compositional series. We show that trap occupation governs carrier dynamics and defect-parameter identifiability in semiconducting materials: weakly occupied states exhibit electron-capture-coefficient–trap-density degeneracies, whereas trap filling lifts them. In our perovskite systems, a non-degenerate signature $T\beta$, characterized by a strongly asymmetric $\beta_p/\beta_n$ capture-coefficient ratio, occurs across all compositions, suggesting substantial trap filling is a general feature of perovskite carrier dynamics. We further identify $T\alpha$ as a shared, device-performance-limiting non-radiative recombination channel, while a shallow $T\epsilon$ signature unique to FAPbI$_3$ produces the largest steady-state non-radiative recombination rate and is consistent with the previously observed high stacking-fault density of this composition. This framework therefore provides a basis for comparing trapping signatures across different semiconducting materials at room temperature.
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All authors Maxim Simmonds, Katarzyna Pydzińska-Białek, Thomas C. Rossi, Mostafa Othman, Aïcha Hessler-Wyser, Christian Wolff, Christophe Ballif, Vincent M. Le Corre, Eva Unger
Chemical Physics
Enriching molecular Raman spectroscopy with vibrational strong coupling
Matteo Castagnola, Anne Todsen Hansen, Morten Hanefeld Dziegiel et al. (+3 more)
Raman spectroscopy is widely used for molecular identification in biological samples, but spectral congestion often obscures key molecular fingerprints. Strategies to enrich vibrational spectra with additional controllable features are therefore desirable. We theoretically show that vibrational strong coupling (VSC) can reshape Raman spectra by reorganizing vibrational energies and intensities. Near-resonant coupling enables the resolution of quasi-degenerate vibrational modes and redistributes Raman activity among molecular vibrations, brightening otherwise Raman-inactive modes. Off-resonant coupling mediates effective interactions between vibrations, leading to tunable intensity reorganizations and spectral shifts via cavity-controlled vibrational mixing. Using a microscopic theory of Raman scattering, we show that observing Raman signals from collective VSC polaritons requires appropriate geometries for the scattering setup, the sample, and the cavity environment, helping to explain why polaritonic Raman signatures have remained challenging to observe experimentally.
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All authors Matteo Castagnola, Anne Todsen Hansen, Morten Hanefeld Dziegiel, Anders Kristensen, Søren Raza, Simone Latini
Chemical Physics
From sparse quantum-computing data to atomistic simulation with universal machine-learning interatomic potentials
Tuan Minh Do, Yuichiro Yoshida, Kenji Ishihara et al. (+1 more)
We propose a framework for incorporating
quantum-computing-based electronic-structure calculations into universal machine-learning interatomic potentials (uMLIPs). Rather than constructing an interatomic potential from scratch, we refine a pretrained DFT-based uMLIP using a small set of accurate reference energies obtained from
quantum computing. We demonstrate the approach for three chemically distinct applications: the Menshutkin reaction, water adsorption in the metal-organic framework HKUST-1, and CO hopping on a high-
entropy-
alloy nanoparticle. For the Menshutkin reaction, fine-tuning on gas-phase configurations improves the transition-state energy inside a carbon nanotube but not the product energy. For water adsorption in HKUST-1, fine-tuning with only 14 reference configurations brings adsorption thermodynamics obtained from millions of configurations sampled by Widom insertion into closer agreement with reference values. For CO hopping on an IrPdPtRhRu nanoparticle, the preference for on-top over bridge adsorption is recovered in the finite-temperature free-energy profile obtained from enhanced-sampling molecular dynamics, even though the reference data contain only energies. These results demonstrate that the proposed framework provides a practical route for incorporating
quantum-computing calculations into realistic atomistic simulations and that
quantum-computing reference data can improve pretrained uMLIPs.
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All authors Tuan Minh Do, Yuichiro Yoshida, Kenji Ishihara, Wataru Mizukami
Soft Condensed Matter
Granular structure and heterogeneous deformation preceding avalanches
Ibrahim Awada, Michel Bornert, Vincent Langlois et al. (+1 more)
Granular packings undergo intermittent rearrangements, known as precursors, before avalanche onset. Using grain-scale tracking in an inclined granular layer, we show experimentally that the number and recurrence of precursors change with the compatibility between the anisotropic structure inherited from preparation and the subsequent loading direction. Preparation also modifies the propagation of the mobility front, defined as the region in which the packing undergo measurable displacement: frequent precursors produce small progressive advances, whereas rare precursors involve larger extensions. By contrast, several features remain unchanged across protocols. The ensemble-averaged displacement always decays exponentially with depth over approximately four grain diameters, while the local shear-strain variance follows a common quadratic scaling with the mean strain. A two-state model suggests that, regardless of the packing structure, local strain heterogeneities affect approximately one quarter of the elementary
cells, superimposed on the exponential strain profile. The reported results separate preparation-dependent precursor activity from the robust spatial features of the deformation preceding avalanches.
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All authors Ibrahim Awada, Michel Bornert, Vincent Langlois, Julien Léopoldès
Nuclear Experiment
First observation of the fine structure of the Pygmy Dipole Resonance in a nucleus away from stability via the $\beta^-$ decay of $^{92}$Rb to $^{92}$Sr
P. Spagnoletti, M. Ramalho, S. Tahtela et al. (+52 more)
A comprehensive $\gamma$-ray spectroscopy study of excited states in $^{92}$Sr populated via $\beta^-$ decay of $^{92}$Rb ($J^{\pi}=0^-$, $Q_{\beta}=8095(6)$~keV) was performed with the GRIFFIN spectrometer at the Isotope Separator and Accelerator (
ISAC) radioactive ion beam facility at TRIUMF. The high $\gamma$-ray efficiency of the GRIFFIN spectrometer combined with the intense rubidium beams produced allowed for 864 $\gamma$-ray transitions to be placed in the level scheme with 190 excited levels populated, most of them identified for the first time. The excitation energies of low-
spin states in $^{92}$Sr are well reproduced by large-scale Shell Model calculations up to 5~MeV. The $\beta$-feeding intensities are in very good agreement with results from a recent study employing Modular Total Absorption Spectroscopy, indicating a significant suppression of the Pandemonium effect. The experimental picture reveals the energy level dependence of log~$ft$ values in unprecedented detail. These log~$ft$ values are well reproduced by Multiple-Commutator Model calculations that identify the features in the excited levels' wavefunctions that enable the population of high-lying levels with a low effective Q-value that belong to the Pygmy Dipole Resonance.
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All authors P. Spagnoletti, M. Ramalho, S. Tahtela, E. Kauppinen, J. Suhonen, C. Andreoiu, M. Scheck, V. Vedia, Z. Ahmed, D. Annen, G.C. Ball, G. Benzoni, S.S. Bhattacharjee, H. Bidaman, V. Bildstein, S. Buck, R. Caballero-Folch, R.J. Coleman, S. Devinyak, I. Dillmann, I. Djianto, F.H. Garcia, A.B. Garnsworthy, P.E. Garrett, B. Greaves, C.J. Griffin, G.F. Grinyer, E.G. Fuakye, G. Hackman, D. Hymers, D. Kalaydjieva, R. Kanungo, K. Kapoor, E. Kasanda, W. Korten, N. Marchini, K. Mashtakov, A. Nannini, K. Ortner, B. Olaizola, C. Natzke, C.M. Petrache, M. Polettini, A. Radich, M. Rocchini, N. Saei, M. Satrazani, M. Siciliano, M. Singh, C.E. Svensson, D.A. Torres, R. Umashankar, E. Wadge, T. Zidar, M. Zielinska
Medical Physics
Voxel-Matching NORDIC: Non-local patch formation by time-series similarity increases tSNR in high-resolution BOLD fMRI
Alessandro Nigi, Natalia Petridou and Jeroen C.W. Siero
Submillimeter functional
magnetic resonance imaging (fMRI) based on blood-oxygenation-level-dependent (BOLD) signal enables the study of
brain function at the submillimeter level, uncovering insights into fine-scale organisations like cortical layers and columns. However, its inherently low contrast-to-noise ratio (CNR) and signal-to-noise ratio (SNR) often limit its reliability and applicability. Noise Reduction with Distribution Corrected Principal Components Analysis (NORDIC PCA) is a locally low-rank denoising
algorithm that reduces thermal noise levels in BOLD fMRI in a local patch manner. However, local patches often contain a mixture of signals from multiple tissues that negatively affects the low-rank structure of the patches, which limits the denoising capabilities of the
algorithm. We propose an alternative approach for patch formation by gathering similar non-local voxels, dubbed voxel-matching (VM) NORDIC. The results on submillimeter-resolution BOLD fMRI data indicate that VM-NORDIC effectively promotes the low rank of the patches by boosting signal redundancy, allowing for more efficient noise attenuation. Moreover, the method barely affects spatial smoothness due to the non-local voxel selection based on time-series similarity. In particular, VM-NORDIC outperforms standard NORDIC with default local patching (Standard-NORDIC) in terms of temporal SNR (tSNR) (~9-90% larger than Standard-NORDIC; ~23-250% larger than the original) and spatial smoothness estimates (~20% of the smoothness induced by Standard-NORDIC). These improvements are fundamental to improving the validity and precision of fMRI studies at submillimeter resolutions.
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Mathematical Physics · Cross-listed from math.NA
FrFNO:Injecting the analytic Mittag-Leffler propagator into a resolution-robust neural operator for space-time fractional PDEs
Guofei Pang
Fractional partial differential equations couple a
memory-dependent time derivative with a nonlocal fractional
Laplacian, and their repeated solution under varying fractional orders, initial data, or diffusivity fields is computationally expensive. Neural operators offer a fast surrogate, but standard architectures must relearn the dominant linear fractional
evolution from data. We propose the Fractional
Fourier Neural Operator (FrFNO), a resolution-robust conditional operator. It injects the analytic Mittag–Leffler response of the frozen linear part as a once-precomputed, resolution-independent propagator table, and trains a spectral convolutional network only on the residual induced by variable coefficients and nonlinear advection, conditioned continuously on both fractional orders. The central theoretical result is that under zero-shot super-resolution the injected propagator fills the out-of-band modes that a standard
Fourier neural operator sets to zero, replacing the out-of-band full-field tail by the smaller residual tail (a $K$-independent constant-factor reduction under weak perturbation). The residual and the full solution carry the same Sobolev order, so the advantage is amplitude reduction rather than a steeper tail. Mesh refinement drives the error to a residual-controlled floor. On a nonlinear two-dimensional space–time fractional Burgers problem FrFNO achieves the lowest relative $L^2$ error among six baselines (FNO, PINO, PDNO, CNO, DeepONet, U-Net) at the training resolution and under zero-shot super-resolution, yields the smallest spectral phase error, and remains the best at the integer-order limit and for long integration windows. The same construction extends to coupled fractional systems such as fractional Allen-Cahn and Navier–Stokes equations. Code, training scripts, and reference outputs are available at https://github.com/Derek2021Pang/FrFNO.
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Statistical Mechanics
The charge dependent hard-sphere model: Polycrystals as low-energy configurations
Leonard Kreutz and Timo Ziereis
We investigate the emergence of rigid polycrystalline structures in atomistic ionic particle systems as low-energy configurations. The interaction between particles of opposite charge is modeled by hard spheres that interact when they are tangential. The interaction between particles of same charge is modeled as a hard repulsion that forces a minimal distance between them. The atomistic energy is frame invariant, and no underlying reference
lattice is assumed on the ionic configurations. The asymptotic behavior of configurations with finite surface energy scaling is identified by means of $\Gamma$-convergence. The related continuum theory is described by piecewise constant fields that encode the local orientation of the configuration. The limiting energy is local and concentrates at grain boundaries, which correspond to the boundaries of the regions where the underlying configuration has a constant orientation. The limiting energy density is anisotropic and depends on the relative misorientation of the two grains, their translation misfit, and the normal to their interface. Furthermore, we perform a fine analysis of surface energies for solid-solid and solid-
vacuum phase transitions and determine energetically favorable orientation mismatches. This relies on a structure result for our grain boundaries, which shows that, due to the rigid setup, interpolating layers near the grain interface are energetically not favorable.
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Optics
Mechanical Activation of Terahertz Tunneling in Metallic Nanogaps
Dasom Kim, Dukhyung Lee, Young-Mi Bahk et al. (+1 more)
Metallic nanogaps concentrate terahertz (THz) fields into deep subwavelength volumes and support field-driven electron tunneling when the insulating barrier becomes sufficiently narrow. Here, we demonstrate mechanical control of tunneling-mediated nonlinear THz transmission in a flexible nanogap metasurface. The metasurface consists of Au/PMMA/Au nanogaps fabricated on a polyethylene terephthalate substrate, enabling continuous tuning of the gap geometry through macroscopic bending. In the flat state, the resonant transmission exhibits only a weak dependence on the incident THz field strength. Upon bending, increasing the incident field strength induces pronounced resonance suppression accompanied by saturation of the voltage developed across the nanogaps. This nonlinear response is consistent with the opening of a field-dependent tunneling conduction channel through the mechanically narrowed PMMA barriers. Simmons-model calculations illustrate the strong increase in tunneling current density and the associated dissipative gap response as the local gap width approaches the few-nanometer regime. These results establish mechanical deformation as a macroscopic means of controlling tunneling-mediated THz nonlinearities in flexible metasurfaces.
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All authors Dasom Kim, Dukhyung Lee, Young-Mi Bahk, Dai-Sik Kim
Quantum Physics
Optimal control for duty-cycle-limited interferometry with single-NV centers
Ugur Tamer, Sina Zeytinoglu and Ozgur E. Mustecaplioglu
Stimulus-responsive hydrogels convert temperature changes into
magnetic-field shifts detectable by nitrogen-vacancy (NV) centers, enabling nanoscale thermometry in soft and biological environments. Existing hydrogel-nanodiamond demonstrations rely on NV ensembles, whose high
photon throughput is accompanied by gradient-induced inhomogeneous broadening, while idealized single-NV projections assume high-fluence fluorescence/ODMR readout. Here we study a pulsed single-NV route for the same class of sensors and ask whether decoherence-aware coherent control can improve thermometric performance over optimized Ramsey interrogation at equal detected-
photon budget. Using a sigmoidal volume-phase-transition model, dipolar
magnetic transduction, and Lindblad master-equation simulations, we find a reproducible 25-27% per-shot sensitivity gain over optimized Ramsey, i.e., a 57-60% gain in Fisher information (1.57-1.60). The same gain carries over to the
photon-normalized Fisher information. The rate gain is governed by the measurement duty cycle, the fraction of the experimental cycle spent accumulating signal rather than initializing, reading out or waiting, and becomes largest when the overhead or optical-dose constraint dominates the cycle time. The optimized trajectories reveal a response-shaping mechanism in which phase accumulation is concentrated near the end of the sequence, and a closed-form depth-two solution reproduces the numerical optimum and exhibits that mechanism analytically. The advantage is most pronounced when the dephasing time is short compared with the measurement overhead or dose-limited waiting time, which is the operating regime targeted by hydrogel-transduced single-
spin biosensing.
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Nuclear Experiment
Direct measurement of Enhanced octupole collectivity in 148Dy
P. Spagnoletti, V. Vedia, E. Yuksel et al. (+36 more)
Excited states in $^{148}_{~66}$Dy were populated via $\beta^+/EC$ decay of $^{148m}$Ho using the GRIFFIN spectrometer at the TRIUMF
ISAC-I facility. A combined measurement of the mean lifetime of the $3_1^-$ level using the Generalized Centroid Difference (GCD) method and branching fraction of the $3_1^-\rightarrow0_1^+$ $\gamma$-ray decay has been performed. From these results, an enhanced electric octupole $B(E3;3_1^-\rightarrow0_1^+)$ transition strength of 46(3)~W.u. has been determined in $^{148}_{~66}$Dy. This is the largest measured value across the closed
neutron shell at $N=82$ and provides direct evidence of enhanced octupole collectivity beyond $Z=64$. The
evolution of the $B(E3; 3^-_1 \rightarrow 0^+_1)$ strength along the $N=82$ isotonic chain is compared with quasiparticle random-phase approximation (QRPA) calculations using the SkI3 and SkM$^*$ Skyrme energy-density functionals, as well as with large-scale shell-model (SM) calculations. This result extends the boundaries of enhanced octupole collectivity far from the so-called `octupole magic numbers' $Z=56$ and $N=88$.
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All authors P. Spagnoletti, V. Vedia, E. Yuksel, Y. X. Yu, G. J. Fu, R. Umashankar, G. Andreetta, C. Andreoiu, A.A. Avaa, G.C. Ball, V. Bildstein, S. Buck, E. Cantacuzene, G. Colombi, I. Dillmann, L. P. Gaffney, A.B. Garnsworthy, P.E. Garrett, G.F. Grinyer, G. Hackman, J. Liu, A. Ludlam, L.L. Luperi, Madhu, T. La Marca, D. Movilla-Quintero, S. Murillo Morales, R. Nicolas del Alamo, M.M. Rajabali, P.H. Regan, M. Rocchini, M. Scheck, J. Seger, S. Sekal, D. Stramaccioni, C.E. Svensson, A. Tsantiri, J. Williams, F. Wu
Solar and Stellar Astrophysics
The independence of the mid-infrared RR Lyrae Period-Luminosity relation from metallicity from a study of three globular clusters in the Large Magellanic Cloud
Steve Ardern, Vicky Scowcroft and Stijn Wuyts
RR Lyrae are pulsating variable
stars tracing old ($>10$ Gyr)
stellar populations, and exhibit a strong mid-infrared Period-Luminosity (PL) relation that can be calibrated with known parallaxes to infer distances. Here we present Period-Luminosity relations and distance
moduli for three isolated globular clusters in the Large Magellanic Cloud: Reticulum, NGC 1841, and NGC 1466. Our analysis uses legacy Spitzer Space
Telescope images obtained by the Carnegie RR Lyrae Program, and an internally self-consistent sample restricted to RRab
stars, with cluster membership confirmed using
Gaia DR3 proper motions and photometry. In the Spitzer 3.6~$\mu$m band, we simultaneously fit a PL for these clusters using a slope derived from
Galactic Globular Clusters, yielding extinction-corrected distance
moduli of $18.47\pm0.09$ mag for Reticulum, $18.29\pm0.09$ mag for NGC 1841, and $18.61\pm0.09$ mag for NGC 1466. The latter two are the first RR Lyrae PL-based distance
moduli for these clusters, and all three are consistent with literature values from other techniques. Additionally we fit a PL with slope as a free parameter, and find that this LMC-derived PL is consistent with that derived from
Galactic GCs. Simultaneously fitting a PLZ for the three clusters yields a
metallicity coefficient $c= -0.03\pm0.05~\mathrm{mag}~\mathrm{dex}^{-1}$ which can be considered a negligible dependence of the PL on
metallicity ($|c| <0.1$ mag dex$^{-1}$). Modelling an intrinsic width, $W$, to the PL/ PLZ yields a consistent value $W\approx0.1\pm0.02~\mathrm{mag}$, suggesting intrinsic width is not driven by
metallicity.
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Nuclear Theory
Microscopic analysis of M1 scissors mode in $^{254}$No
V.O. Nesterenko, M.A. Mardyban and A. Repko
The low-energy $M1$ orbital scissors mode (SM) was recently observed by Oslo group in deformed
nucleus $^{254}$No. This is the heaviest
nucleus where SM was ever experimentally found. We propose the analysis of SM, together with the
spin-flip $M1$ resonance, within fully self-consistent Quasiparticle Random-Phase Approximation (QRPA) with Skyrme forces SG2, SLy4 and SLy5. The impact of "tensor" $J^2$-term, introduced by perturbative (on the base of SG2) and consistent (SLy5) ways, is analyzed and shown to be noticeable but not decisive. The deformation-induced coupling of $M1$ and $E2$ states is inspected. The calculations reasonably describe Oslo's experimental data. The best agreement is obtained for SLy5. A fine structure of SM in $^{254}$No is predicted. A significant constructive interference of the dominant orbital and minor
spin-flip contributions to $M1$ strength at SM energy region is found. What is remarkable, our analysis of distributions of the convective
nuclear currents challenges the scissors-like flow usually assumed for SM.
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Mesoscale and Nanoscale Physics
Rydberg excitons in core-shell nanostructures I. Optical properties
Sylwia Zielińska-Raczyńska, Gerard Czajkowski and David Ziemkiewicz
Optical properties of Cu$_2$O-metal core-shell nanostructures containing Rydberg
excitons are examined. Calculations of electron and hole eigenfunctions and eigenenergies are used to calculate
exciton energy and its dependence on system geometry and dimensionality. The limits of very small and very large structures are discussed, making the results applicable to low principal
quantum number
excitons as well as to Rydberg states. The Real Density
Matrix Approach method is used to calculate the optical properties of the studied systems.
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Astrophysics of Galaxies
An Orbital Interpretation of Decreasing Galaxy Velocity Distance Relations in Systems Dominated by Giant Elliptical Galaxies
Rabia Melati, Takia Larbaoui, Mohammed Ridha Benzidane et al. (+1 more)
The persistence of approximately flat rotation curves observed in many
galaxies, is commonly interpreted as evidence for extended dark matter
halos or as an indication of modified gravitational laws at low accelerations. In this work, we investigate an alternative orbital framework for the large scale kinematics of
galaxy systems dominated by
giant elliptical
galaxies. We propose that selected non active companion
galaxies form gravitationally bound orbital systems around a dominant central elliptical
galaxy, conceptually analogous to the
Solar System Using
galaxy group catalogs together with data from the NASA IPAC Extragalactic Database, we analyze three independent systems centered on M87, M60, and NGC 1399. Candidate companions are selected according to common observational and dynamical criteria, including their location within the adopted search volume, approximate spatial coplanarity, and consistency of the effective gravitational parameter (Geff). For the three systems, the resulting velocity distance relations exhibit clear decreasing trends with increasing distance from the central elliptical
galaxy, qualitatively consistent with Keplerian like orbital dynamics.
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All authors Rabia Melati, Takia Larbaoui, Mohammed Ridha Benzidane, Mourad Lounis
Cosmology and Nongalactic Astrophysics
21-cm Constraints on S-wave Dark Matter Annihilation with Subhalo-enhanced Effects
Zixuan Xu and Sibo Zheng
Observations of the 21-cm signal can probe energy injection into the intergalactic medium arising from dark matter annihilation during
cosmic dawn and reionization. For s-wave annihilation, the annihilation rate depends on the squared dark matter density, making the 21-cm signal sensitive to dark matter
halo substructure. In this work, we extend the numerical method of DM21cm to address spatially inhomogeneous s-wave annihilation including subhalo effects, using semi-analytical treatment of SASHIMI-C. Our numerical results show that the projected HERA limit for the $\gamma\gamma$ annihilation channel is stronger than the Leo~T bound within the dark matter mass range of $m_{\chi}\leq 3\,{\rm keV}$, whereas the projected HERA limit for the $e^+e^-$ annihilation channel is the strongest among the existing bounds for $m_\chi\sim 0.1$–$1\,{\rm GeV}$.
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Instrumentation and Methods for Astrophysics
Development of a Temperature-Variable Cold Blackbody Calibrator for Millimeter and Submillimeter Wave Detectors
Kazuki Watanabe, Taiki Sato, Shuhei Inoue et al. (+3 more)
We report the design, fabrication, and characterization of a cryogenic blackbody calibrator intended for laboratory-based detector characterization, providing multi-temperature calibration of millimeter- and submillimeter-wave detectors over a temperature range of 4 K to ~10 K. The device employs a Stycast/SiC absorber shaped for uniform array illumination and mounted on a phosphor-bronze substrate with optimized thermal links. Measured thermal conductance and heat capacity show the expected temperature dependence, although the conductance was lower than estimated, yielding a thermal time constant of 8.5 s at 10 K versus the 3.7 s design estimate. The response remains practical, demonstrating the calibrator's effectiveness as a stable reference source for precise calibration of detector arrays.
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All authors Kazuki Watanabe, Taiki Sato, Shuhei Inoue, Shinsuke Uno, Tatsuya Takekoshi, Tai Oshima
High Energy Physics (Theory)
A Geodesic Route toward Holography beyond AdS: Tessellating the Schwarzschild Black Hole
Shi Gu, Qiang Wen, Haocheng Zhong et al. (+1 more)
In
vacuum anti-de Sitter (AdS) space, the geometry admits a perfect tessellation by a geodesic network. This tessellation characterizes the background exactly, and a partial
entanglement entropy (PEE) tensor-network toy model of AdS/CFT can be defined on it. It has so far been unclear whether this construction can be extended beyond
vacuum AdS. In this paper we take the first step in this direction. We show that the exterior region of the Schwarzschild black hole and its Einstein–Rosen bridge are perfectly tessellated by a specific geodesic gas emitted from the boundary, so that Crofton reconstruction holds in these regions. We then prove that such a geodesic tessellation and the Crofton reconstruction it defines extend to more generic Riemannian
manifolds. This allows us to construct a PEE tensor-network model of
holographic duality on more generic
geometric backgrounds. In the case of the PEE tensor-network model for the Schwarzschild background, we can concretely realize the Bekenstein–Hawking
entropy, the Ryu–Takayanagi formula and the ER=EPR proposal. Our approach opens a new route towards
holographic toy models beyond AdS/CFT.
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All authors Shi Gu, Qiang Wen, Haocheng Zhong, Yiwei Zhong
High Energy Physics (Phenomenology)
Localized CP violation driven by cross-channel interference between $\overline{K}_0^*(1430)^0$ and $\rho(770)^0$ in $B^{\pm}\rightarrow K^{\pm}\pi^{+}\pi^{-}$ decays
Jin-Zhao Guo and Gang Lü
For the charmless three-body decay $B^{\pm} \rightarrow K^{\pm} \pi^{+} \pi^{-}$, a CP asymmetry sign reversal typically occurs in the low-$m_{\pi\pi}$ region. However, experimental data reveals a localized anomaly in the specific phase space region $0.4 \text{ GeV}^2 < m_{\pi\pi}^2 < 0.8 \text{ GeV}^2$ and $1.5 \text{ GeV}^2 < m_{K\pi}^2 < 2.5 \text{ GeV}^2$, where the regular pattern is broken by a rightward tilt. In this work, we investigate the dynamical origin of this phenomenon by employing a quasi-two-body factorization scheme that integrates short-distance perturbative QCD (PQCD) hard kernels with long-distance $S$-wave LASS and $P$-wave relativistic Breit–Wigner(RBW) line shapes. Our results demonstrate that the localized anomaly is driven by cross-channel interference between the scalar $\overline{K}_0^*(1430)^0$ and vector $\rho(770)^0$ resonances, which exhibit an orthogonal
geometric topology on the Dalitz plot. Crucially, we show that the rapid variation of the relative strong phase within the intersection region induces coherent interference effects alternating between the charge-conjugated channels, significantly reshaping the local CP asymmetry profile. This cross-channel dynamics framework provides a self-consistent theoretical
benchmark for overlapping resonance regions, offering valuable insights for upcoming high-luminosity experiments at Belle II and the HL-LHC.
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Quantum Physics
Quantum Loads and the Generalized Telegrapher's Problem
E. Collin and A. Delattre
We report on the mapping of classical microwave transmission line theory onto the
quantum scattering
matrix description. By means of a generalized flux formalism a la Devoret, we derive a charge-current vector living on the confining electrodes, to which a Hodge-like decomposition is applied. The presented theory holds equally well for all types of waves traveling within Cartesian and cylindrical guide geometries (the usual Transverse Electric
Magnetic, but also Transverse
Magnetic and Transverse Electric ones). We then demonstrate how a generic load decomposes into a series of complex coefficients $Z_{load}(\alpha)$, for each mode $\alpha$ propagating along the line. This decomposition leads to a particular classification of traveling waves: gradient-type and curl-type charge-currents. This distinction shines a new light on a broken gauge
symmetry exhibited by a class of Transverse Electric modes. Our results provide a universal theoretical framework, which finds a direct usage in microwave-based
quantum information transfer.
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Chemical Physics
A fast physics-based matrix model for the impedance of a PEM fuel cell: Incorporating functionally graded catalyst layer and channel impedances
Andrei Kulikovsky
We extend a recent physics-based
matrix model for calculating PEM fuel
cell impedance (doi:10.1149/2754-2734/ad6ce8) to cases of low air flow stoichiometry and functionally graded cathode catalyst layers (CCLs). We demonstrate that the
matrix model produces accurate spectra and is almost three orders of magnitude faster than a model based on the standard boundary-value problem solver. The physics-based
matrix model can compete with equivalent
circuit models for fitting experimental EIS spectra, particularly those measured from
cells with functionally graded CCL.
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High Energy Physics (Phenomenology)
The high-velocity dark matter halo of the Milky Way in light of the LZ 248 keV event
Ciaran A. J. O'Hare
The interpretation of high-energy
nuclear recoil events in direct-detection experiments can depend sensitively on the poorly understood high-speed tail of the
Galactic dark matter velocity distribution. This fact has been brought into sharper focus recently by an anomalous
nuclear-
recoil event at $E_R\approx248~\mathrm{keV}$ observed by the LZ experiment. If interpreted as caused by a dark-matter-induced
recoil, kinematic constraints on many models imply this particle would have to emerge from the high-speed tail. Here, we re-assess this astrophysical uncertainty using Milky Way analogues from the IllustrisTNG and FIRE simulations. We find that the maximum laboratory-frame DM speed on June 16, when the event was observed, is $792.7^{+82.9}_{-95.6}\, \mathrm{km/s}$ (median and 95% containment across simulations), with a median very close to the fiducial SHM value. Modelling the tail of the velocity distribution in three dimensions is complicated by the fact that these simulated dark matter
halos are anisotropic and are generically seen to
spin in the same direction as the baryonic disk. However, we find that this does not reduce the maximum laboratory-frame DM speed because the approximately Gaussian azimuthal velocity distribution is negatively skewed by this co-rotation, rather than shifted by it. We illustrate these results in the context of an inelastic dark matter interpretation of the LZ event.
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Optics
Topological characterization of a reconfigurable synthetic-frequency SSH lattice on an integrated lithium-niobate platform
Hiep Xuan Dinh, Armandas Balčytis, Guanghui Ren et al. (+3 more)
Synthetic frequency dimensions provide a powerful and highly reconfigurable platform for topological photonics. However, experimentally identifying their topological phases remains challenging because these systems do not naturally provide well-defined boundaries or readily accessible edge-state signatures. Here, we realize a reconfigurable Su-Schrieffer-Heeger (SSH)
lattice in a synthetic frequency dimension using an integrated thin-film lithium-niobate photonic molecule and directly measure its
topology. Electro-optic coupling between staggered resonator supermodes enables independent control of the effective intra-
cell and inter-
cell hopping strengths, enabling dynamic switching between trivial and non-trivial topological phases on the same chip. We validate the transition through two independently derived bulk topological invariants: direct
retrieval of Zak phase from time-resolved synthetic-dimension band-structure spectroscopy; and extraction of the winding number using mean-
chiral-displacement method from site-resolved steady-state measurements. Both approaches consistently identify the topological transition and agree closely with theoretical predictions. Our results demonstrate experimentally accessible, boundary-independent methods for characterizing
topology in synthetic-frequency
lattices. More broadly, the integrated and dynamically reconfigurable photonic platform provides a scalable framework for bulk topological characterization and programmable topological photonic systems.
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All authors Hiep Xuan Dinh, Armandas Balčytis, Guanghui Ren, Mei Xian Low, Arnan Mitchell, Thach G. Nguyen
Mathematical Physics
J. Fransson and A. P. Sowa
We introduce a new model for a system of interacting
bosons placed in an array of sites. At its core is a nonlinear, nonlocal
evolution equation, which we have dubbed the Schrödinger-Dirichlet equation. The construction is closely related to the Bose-Hubbard model and to a specific type of generalized
bosons. In contrast to conventional mean-field closures, the resulting nonlinear dynamics need not preserve product structure and can generate
entanglement from initially separable states. The relevant methods of analysis are based on harmonic analysis for the multiplicative group of positive rationals.
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Mathematical Physics
Gradient nature of Laplacian growth
A. Zabrodin
For a class of growth processes of
Laplacian type in the plane, we suggest an interpretation as a “gradient descent” in the space of smooth closed curves. More precisely, we show that boundary of a growing domain moves along a gradient of a certain functional in the space of curves. In the simplest cases this functional is $\log (1/r)$, where $r$ is the external conformal radius of the growing domain.
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