Atomic Physics
Observation of multiphoton entanglement in resonance fluoresce
Xiao-Long Zhou, Jian Wang, Ze-Min Shen et al. (+8 more)
Resonance fluorescence, the process in which a single two-level
quantum emitter interacts with a near-resonant coherent light, is a cornerstone of
quantum optics as a paradigmatic light-matter interaction.
Quantum phenomena in resonance fluorescence have been accounted for in terms of one- and two-
photon processes; however, the physical processes arising from the interaction of a single two-level atom with higher
photon numbers remain unexplored experimentally. Here we experimentally reveal the multiphoton scattering nature of resonance fluorescence, which intrinsically gives rise to multiphoton
entanglement. By accessing
quantum fluctuations in the field emitted from a cavity-
quantum electrodynamics system, we resolve third- and fourth-order
photon scattering events from a single two-level atom. In the three-
photon component, the scattered
photons are shown to be genuinely energy-time entangled, as verified by a violation of Svetlichny's inequality. As a demonstration of an application, a
quantum secret sharing protocol (QSS) is implemented using this entangled
photon source. Our study refines the descriptive framework of resonance fluorescence and broadens the scope of its investigation. It also establishes a fundamentally simple route for generating multiphoton entangled states for
quantum information processing and
quantum metrology.
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All authors Xiao-Long Zhou, Jian Wang, Ze-Min Shen, Dong-Yu Huang, Si-Jian He, Qi-Yang Huang, Yi-Jia Liu, Yu-Shu Chen, Quan Jiang, Chuan-Feng Li, Guang-Can Guo
Quantum Physics
90%-Efficient Optical Storage in a Rare-Earth Crystal with a Low-Loss Impedance-Matched Cavity
Weiye Sun, Fudong Wang, Mucheng Guo et al. (+7 more)
High-efficiency optical storage in rare-earth-ion-doped
crystals is challenging because of their typically weak optical absorption,which makes cavity-enhanced
memories highly sensitive to parasitic intracavity loss. Here we demonstrate a 90.1(5)% storage efficiency for coherent optical pulses in an impedance-matched cavity atomic-frequency-comb
memory based on Eu3+:Y2SiO5. The Brewster-angle configuration of the
crystal and fully cryogenic Fabry-Pérot cavity reduce the round-trip intracavity loss to 0.37%. Quantitative modeling shows that further improvement is limited primarily by AFC preparation and its associated dispersive response rather than by residual cavity loss,identifying the principal requirements for further approaching unity efficiency.
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All authors Weiye Sun, Fudong Wang, Mucheng Guo, Xiantong An, Zhenqi Xu, Zhehao Xu, Xingmin He, Matthew J.Sellars, Shuping Liu, and Manjin Zhong
Optics
Aberration sensing in fluorescence microscopy using quantum correlations
Shay Elmalem, Shaurya Aarav, Allard K. F. Hübler et al. (+2 more)
Widefield fluorescence microscopy is an essential biological imaging tool, yet its penetration depth is fundamentally restricted by tissue-induced aberrations. Correcting these requires precise characterization of the point spread function (PSF), but existing wavefront sensing techniques rely either on often-unavailable guide
stars, or on computationally heavy indirect phase
retrieval methods, that could struggle in low-contrast regions. Here, we show that the PSF can be mapped directly and non-invasively by exploiting
quantum correlations between
photons. Standard fluorophores inherently exhibit
photon antibunching, effectively acting as sources of “missing”
photon pairs. By capturing these correlation statistics across a wide field of view using a single-
photon avalanche diode (SPAD) array imager, we extract the local PSF autocorrelation directly from the fluorescence emission itself. This approach bypasses the limitations of classical intensity measurements, requiring no iterative or complex numerical optimization. We demonstrate widefield direct PSF
retrieval in a second or less, paving the way for real-time operation. By translating
quantum optical concepts to conventional fluorescent probes, this technique provides a robust, direct pathway to deep-tissue adaptive optics in life sciences.
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All authors Shay Elmalem, Shaurya Aarav, Allard K. F. Hübler, Hugo Defienne, Dan Oron
Soft Condensed Matter
Spontaneous filament formation and network self-assembly via active phase separation
Elena Lucas, Varun Venkatesh and Amin Doostmohammadi
We introduce Active Model H$^{-}$, a scalar phase-field model of non-
equilibrium phase separation in the overdamped hydrodynamic limit, and show that it produces filamentous networks with enhanced connections and arrested coarsening, a morphology not observed in existing scalar active field theories. Isolated filaments are unstable to spontaneous bending, and the resulting
curvature drives self-propulsion towards the convex side, causing them to collide and assemble into a percolating network. The networks are locally non-
equilibrium, with anomalously curved edges, disordered vertex angles and heterogeneous topological charge, yet recover Lewis's law macroscopically. Under noise they show balanced break and reform dynamics.
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High Energy Physics (Theory)
Variational Solution of Non-Hermitian Quantum Field Theory in Two Dimensions
Paul Romatschke
This work describes a variational technique to solve non-Hermitian
quantum systems, in particular those with negative coupling quartic self-interaction. Differences of applying variational methods from standard
quantum mechanics to non-Hermitian
quantum mechanics – including potential pitfalls – are highlighted. A successful implementation of the variational approach for the non-Hermitian case is presented. The technique is used to analyze scalar
quantum field theory in d=2 with negative quartic self-interaction in the
Hamiltonian formulation in
lattice discretization.
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Strongly Correlated Electrons
Pressure induced structural phase transition and magneto-elastic coupling in Eu doped LaCrO$_3$
Asish Kumar Mishra, Mrinmay Sahu, Bhagyashri Giri et al. (+8 more)
In this study, we have carried out a detailed high pressure investigation on 5$\%$ Eu doped LaCrO$_3$ (ELCO) using synchrotron X-ray diffraction (XRD), micro Raman spectroscopy, and low-temperature magnetization measurements to correlate the structural and
magnetic properties under pressure. The high pressure XRD reveals the orthorhombic to rhombohedral structural phase transition around 10.6 GPa. The high pressure Raman data corroborate this result and indicate that the
lattice instabilities associated with the low-frequency soft modes play a crucial role in driving this transition. In addition, a pronounced anomaly in the Raman shift and integrated intensity of several Raman modes is observed around 4.5 GPa. By combining the low-temperature magnetization measurements with the anomalies observed in the XRD and Raman data and by comparing with the similar results in LaCrO$_3$ (LCO), a pressure-induced change in the
magnetic ground state to
antiferromagnetic ordering is predicted.
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All authors Asish Kumar Mishra, Mrinmay Sahu, Bhagyashri Giri, Bidisha Mukherjee, Suvashree Mukherjee, Harekrishna Bhunia, Tamalkanti Mukherjee, Sujoy Ghosh, Partha Mitra, Peter Liermann, Goutam Dev Mukherjee
Earth and Planetary Astrophysics
Widespread plasma jets in the Martian magnetosheath revealed by dual-spacecraft observations
Abigail Tadlock, Chuanfei Dong, Chi Zhang et al. (+4 more)
Plasma jets in planetary magnetosheaths are transient, high dynamic pressure structures capable of strongly perturbing downstream magnetospheres and modulating
solar wind energy transfer. Although recently identified at Mars, their formation mechanisms and global occurrence remain poorly constrained. Using dual-spacecraft observations from Mars Atmosphere and Volatile
EvolutioN (MAVEN) and Tianwen-1, we show that magnetosheath jets occur throughout the Martian magnetosheath, in striking contrast to Earth where jet occurrence is strongly controlled by interplanetary
magnetic field orientation and largely confined to quasi-parallel shock regions. We propose that this widespread distribution is linked to Mars' extended hydrogen corona, which generates pickup ions that drive
proton-cyclotron waves upstream of the bow shock. Because this mechanism is generic to any body with an extended corona (or exosphere) embedded in a
stellar wind, this finding bears on
solar-wind interactions at comets and other small bodies, and on the space environments of unmagnetized terrestrial
exoplanets. These results indicate that magnetosheath jet formation can be governed not only by external
solar wind forcing but also by intrinsic planetary properties, pointing to a previously unrecognized pathway for
solar wind-
planet coupling at unmagnetized worlds.
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All authors Abigail Tadlock, Chuanfei Dong, Chi Zhang, Savvas Raptis, Hongyang Zhou, Xinmin Li, Jiawei Gao
Optics · Cross-listed from cs.LG
Learning-Based Reconstruction of Optical Properties in Bilayered Media from Single-distance Time-Resolved Reflectance Measurements
Caterina Amendola, Giulia Maffeis, Lorenzo Buffoni et al. (+8 more)
The inverse problem of reconstructing optical properties, specifically absorption and scattering coefficients, in layered biological media from time-domain reflectance measurements remains a significant challenge for traditional analytical models. Inverse solvers based on the
diffusion equation often struggle with structural heterogeneity, frequently yielding poor accuracy for superficial absorption and deep-layers scattering. In this work, we propose a machine learning framework as an alternative approach to reconstruct the optical properties of a bilayered medium, benchmarking its efficiency and accuracy against model-based
algorithms. To overcome the intrinsic approximations of
diffusion theory and inverse reconstruction, we generated a robust synthetic
dataset of forward DTOF using exact Monte Carlo simulations at multiple source-detector distances. A machine learning pipeline was then trained on this
dataset and validated against state-of-the-art model-based reconstruction methods. Besides the significant reconstruction speed-up, the machine learning approach achieves higher accuracy than model-based inverse solvers, further providing an estimate of the parameter space dimensionality without requiring any a priori information about the number of layers in the investigated geometry. Further enhancements in the reconstruction accuracy can be expected in future extensions of this work, by training the pipeline over multiple DTOF curves from the same medium, in a joint multi-distance reconstruction approach.
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All authors Caterina Amendola, Giulia Maffeis, Lorenzo Buffoni, Lorenzo Chicchi, Francesco Coghi, Duccio Fanelli, Raffaele Marino, Fabrizio Martelli, Riccardo Paoli, Lorenzo Pattelli, Lorenzo Spinelli
Mathematical Physics
Classification of pairs of second-order Hamiltonian operators and hydrodynamic type systems in six components
Giorgio Gubbiotti, Lambertus Van Geemen and Pierandrea Vergallo
Following a recent characterisation of hydrodynamic systems with second-order
Hamiltonian structure in terms of alternating three-forms on the projective space, we present a complete classification of systems in 6 components. We use non-trivial group action techniques to obtain 5 canonical forms. A general result for every dimension is also obtained for one of these cases, whose
geometric structure is strictly related to the
symplectic canonical form.
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Quantum Physics
Transduction-Enabled Superconducting Quantum Repeater: Toward Deterministic Entanglement Distribution with High-Fidelity Gates
Francesco Fiorini, Jing Wu, Andrew Cameron et al. (+5 more)
Long-distance
entanglement distribution is hindered by
photon loss in optical fibers and the nocloning
theorem. Optical
quantum repeater (QR) protocols rely on Bell state measurements (BSMs), they are intrinsically limited to probabilistic
photon operations and fail 50% of the time. We propose a hybrid approach to building
quantum repeaters that combines the high transmission speed of photonic
qubits in optical fiber with the high-fidelity
quantum processing capabilities enabled by superconducting
circuits. The transduction-enabled superconducting QR (TESQR) architecture eliminates the need for probabilistic BSMs and allows deterministic processing operations. The TESQR framework always yields a final state at the remote nodes rather than aborting on
photon loss, manifesting deterministic
entanglement distribution within certain parameter regimes. We evaluate the performance by assessing output-state fidelities and success probabilities of
entanglement distribution using realistic noise models. Additionally, we integrate an
entanglement purification scheme and evaluate the performance through numerical simulations in QuTiP environment. Our results show that, for
entanglement swapping, the proposed scheme improves the
entanglement distribution rate by an average of 63% and by up to 159% compared with photonic-only architectures. Moreover, after purification, the end-to-end fidelities exceed 0.8 over distances up to 20 km.
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All authors Francesco Fiorini, Jing Wu, Andrew Cameron, Changqing Wang, Doga M. Kurkcuoglu, Rosario G. Garroppo, Michele Pagano, Silvia Zorzetti
Quantum Physics
Scalable entanglement distribution using encoded hybrid repeater chains
Stav Haldar, Saikat Guha, Don Towsley et al. (+1 more)
Long-distance
entanglement distribution requires error correction protocols to compensate for
qubit decoherence in
quantum memories and noise introduced during
entanglement swapping. We argue that repeater chains with error-correction capabilities should exploit more than one physical platform, combining the complementary strengths of different
quantum memory technologies into a single hybrid repeater architecture. An important constituent of such an architecture is a hybrid repeater which combines type-1
memories, characterized by fast
entanglement generation rates and suitability for multiplexing, and type-2
memories that offer long coherence times and low two-
qubit gate error rates. Taking the resource-intensive nature of hybrid nodes into account, we propose and analyze repeater chains in which only a subset of nodes need to be hybrid, while the remaining nodes are simpler first-generation repeaters with no error-correction capability. Through detailed Monte Carlo simulations of fault-tolerant encoded repeater chain protocols based on the three-
qubit phase-flip repetition code, the $[[7,1,3]]$ Steane code, and the $[[9,1,3]]$ Shor code, we demonstrate that these hybrid architectures outperform pure architectures based on a single
memory platform in terms of end-to-end
entanglement distribution rate. In our study we develop a full
circuit-level noise model of our architectures and examine the impact of an imperfect interface between the two platforms on our hybrid architecture. We also develop a modified version of the swap-as-soon-as-possible policy with multiplexing, more suited to our architecture where some nodes perform error-correction while others do not. This modified policy significantly reduces the information storage time in
memory qubits relative to the previously considered swap policies in encoded repeater chains.
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All authors Stav Haldar, Saikat Guha, Don Towsley, Filip Rozpędek
High Energy Physics (Experiment)
Status and Prospects of the HEP Statistical Inference Ecosystem
Massimiliano Galli
Statistical inference is a crucial part of HEP analyses. Historically based on RooFit and RooStats, the statistical tools used by the experiments are now facing unprecedented challenges, such as the rapidly growing complexity of statistical models (involving hundreds of parameters of interest and thousands of nuisance parameters), the need for scalable performance in large likelihood minimizations, and the demand for interoperability across an increasingly diverse ecosystem of tools, computational hardware, and frameworks and libraries, especially the ones developed and used within the machine learning world. This contribution summarizes status and future plans for the statistical tools used by some of the main LHC experiments (CMS, ATLAS), with a focus on improvements coming from the ROOT world (RooFit automatic differentiation), interoperability with modern libraries (JAX) and communication across frameworks (HS3).
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Cosmology and Nongalactic Astrophysics
Constraints on the Pop III Sky Surface Brightness from High-Redshift Caustic Transients in MACS0416
Jakob P. Perivolotis, Pietro Bergamini, Rogier A. Windhorst et al. (+18 more)
Population III (Pop III)
stars are hypothetical zero-
metallicity stellar structures formed from
primordial hydrogen and helium. They are theorized to span a wide mass range, extending to several 100
solar masses, and may have played important roles in nucleosynthesis and reionization. Their expected fluxes are far below JWST NIRCam detection limits, making direct observation unlikely. However, extreme magnification near the caustics of massive foreground
galaxy clusters may enable their detection. We search for overlooked high-
redshift (7 <= z <= 17) caustic transits in the
lensing cluster MACS J0416.1-2403. Using three observations spanning 126 days, we create difference images to identify potential candidates. Critical curves for sources at 7 <= z <= 17, derived from a strong-
lensing model, guided visual inspection of three difference-images. No additional transits were found. The longer caustics in our model sweep a larger source-plane area, increasing the probability of detecting an event. Combining this increased statistical sensitivity with deeper imaging, we establish a fainter limit for the unresolved
stellar population at z >= 7. From this null result, we constrain the 100
solar mass 2 micron Pop III sky surface brightness to >= 32.8 +/- 0.6 mag arcsec^-2. Modeling the non-detection as a Poisson process gives a posterior mean caustic-transit rate of 0.29 cluster^-1 yr^-1 and a 95 percent upper credible limit of lambda_95 = 0.86 cluster^-1 yr^-1. The inferred rate remains consistent with the adopted fiducial Pop III caustic-transit model and provides an empirical
benchmark for future multi-epoch monitoring campaigns. This search exploits the fact that individual
stars projected close to source-plane caustics can be briefly magnified far beyond their unlensed fluxes. These constraints provide a direct test of the abundance of luminous Pop III
stars at early
cosmic times.
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All authors Jakob P. Perivolotis, Pietro Bergamini, Rogier A. Windhorst, Erik Zackrisson, Timothy Carleton, Seth H. Cohen, Jordan C. J. D'Silva, Rachel Honor, Rolf A. Jansen, Anton M. Koekemoer, Rafael Ortiz III, Jake Summers, Dan Coe, Christopher J. Conselice, Jose M. Diego, Brenda Frye, Massimo Ricotti, Gibson B. Bowling, Brent Smith, Christopher N. A. Willmer, Haojing Yan
Optics
Rapidity-Coupled Spin Dynamics in Pulsed Laser Fields from Physics-Informed Neural Networks
N. S. Akintsov, A. P. Nevecheria, S. N. Andreev et al. (+1 more)
Carrier-envelope-phase (CEP) stabilized few-cycle pulses make the sub-cycle field structure a control parameter for
laser-driven polarized electron sources, yet
spin solvers for such pulses are rarely tested against exact results. We show that for an electron initially at rest in a linearly polarized plane-wave pulse the rest-frame polarization angle follows the instantaneous vector potential, $\Sigma = 2\arctan(a_x/2) + a_e a_x$ with $a_e$ the electron anomaly: the net rotation vanishes for every CEP, while the peak intra-pulse angle varies over the CEP by 3.02 degrees for a two-cycle and by 0.22 degrees for an eight-cycle pulse. The result follows from the Volkov orbit in longitudinal and transverse rapidities. We use it to validate a light-front reference integrator and a physics-informed neural network trained only on the light-front equations, which reaches $4\times10^{-5}$ in the
spin sector and carries over to elliptical polarization, for which no closed-form solution is known. This gives validated tools for CEP-resolved
spin dynamics in intense fields.
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All authors N. S. Akintsov, A. P. Nevecheria, S. N. Andreev, Qing-Hua Qin
High Energy Physics (Experiment)
Recent benchmarks in the Analysis Grand Challenge and integration with Combine (and HS3)
Peter Fackeldey, Massimiliano Galli, Hannah Havel et al. (+4 more)
The Analysis Grand Challenge (AGC) showcases an example of HEP analysis. Its reference implementation uses modern Python packages to realize the main steps, from data access to statistical model building and fitting. The packages used for data handling and processing (coffea, uproot, awkward-array) have recently undergone a series of performance optimizations. While not being part of the HEP Python (PyHEP) ecosystem, the Combine tool is a pillar of CMS analyses, covering more than 90% of the analyses published in the last few years. As such, it is necessary to have Combine integrated in the PyHEP ecosystem, using the AGC as example. This project also includes, in the long-term, providing support and integration for the High Energy Physics Statistics Serialization Standard (HS3), as a way to have a
language-independent way of representing the likelihood and use different frameworks interchangeably. In these proceedings we cover part of the recent work performed on the AGC and Combine, including: performance
benchmarks, covering benefits introduced by the recent improvements in the data processing packages; examples of how Combine can be integrated and run in a dedicated infrastructure (coffea-casa); and examples and plans to integrate HS3 in Combine.
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All authors Peter Fackeldey, Massimiliano Galli, Hannah Havel, Alexander Held, Iason Krommydas, Oksana Shadura, Nick Smith
Plasma Physics
Indirect-Drive Fusion Target Design for Commercial Fusion Energy
C. R. Weber, A. L. Kritcher, S. Bhandarkar et al. (+26 more)
This paper presents the physics basis for commercially relevant
laser indirect-drive (LID) (radiation-driven) inertial fusion energy (IFE) using a 10 MJ
laser driver. To date, this approach, proven at the National Ignition Facility (NIF), remains the first and only controlled fusion method to demonstrate the key physics required for fusion energy production, including a self-sustained burning
plasma, substantially de-risking the path to commercial fusion energy. Building directly on these results, we present scaled designs to larger target sizes and fusion gains relevant for commercial power generation ($G\sim 26$–$43$). The designs remain close to experimentally demonstrated ignition physics, modifying target components to improve scalability, manufacturability, and cost-effectiveness for fusion energy applications while preserving ignition-relevant implosion physics and fusion power plant compatibility. The baseline platform retains a high-density carbon ablator and clean cryogenic DT fuel layering while extending ignition platforms to substantially larger fuel masses (exceeding 10 times that of current ignition experiments at the NIF) and higher burn fractions ($\sim$40%) with total areal densities at stagnation of $\sim$3~g/cm$^2$. Benchmarked simulations anchored to NIF ignition experiments (using HYDRA and LASNEX) predict that these designs achieve robust ignition and propagating burn at substantially higher fusion yields (265–427~MJ) with significant ignition margin (2–4$\times$ relative to NIF) against hydrodynamic instabilities and representative power-plant non-idealities, including low-mode asymmetry, polycrystalline DT ice roughness, HDC ablator voids, and target-support and fill-hole perturbations. We also show that implosion
symmetry and
laser-
plasma interactions (LPI) can be controlled with our novel multi-beam configuration using thousands of
laser beam-lines.
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All authors C. R. Weber, A. L. Kritcher, S. Bhandarkar, T. Briggs, T. Chapman, T. M. Fears, B. A. Hammel, D. D.-M. Ho, O. Hurricane, B. Kozioziemski, J. Milovich, A. Nikroo, A. Oudin, W. Riedel, A. Wray, N. Alexander, G. Cearley, M. Dunne, J. Gaffney, D. Hammond, J. Kilkenny, R. Lau, J. Lawson, J. Ludwig, B. MacGowan, R. Peterson, V. Smalyuk, R. Toro, Inertia Collaboration
High Energy Physics (Phenomenology)
Hidden charm pentaquarks and the nature of $P_{c}$ states observed at LHCb
Zhi-Biao Liang, Jun-Jie Liu, Mu-Yang Chen et al. (+2 more)
We carry out a unified study of the low-lying $1S$-wave compact states and hadronic molecules composed of hidden charm pentaquarks $qqqc\bar{c}$ ($q=u,d$) within a semirelativistic potential
quark model. Apart from the linear confinement and one-
gluon exchange potential between
quarks and/or antiquarks, one-
boson exchange potential is also included for
baryon and
meson clusters within the pentaquark system. We also evaluate the fall-apart decays by combining the obtained spectra within the
quark exchange model. It is found that the $P_c (4312)^+$, $P_c (4440)^+$, and $P_c (4457)^+$ observed by the LHCb Collaboration in 2019 can be well explained by the hadronic molecules of $[\Sigma_c\bar{D}]_{1/2^-}^{1/2}(4318)$, $[\Sigma_c\bar{D}^*]_{1/2^-}^{1/2}(4437)$, and $[\Sigma_c\bar{D}^*]_{3/2^-}^{1/2}(4458)$, respectively. Meanwhile, $P_c(4380)^+$ reported by LHCb in 2015 may be assigned as the molecule $[\Sigma_c^*\bar{D}]_{3/2^-}^{1/2}(4382)$, except that it turns to be a narrow state other than a broad one shown by the experimental data. Our study shows that the $\sigma$- and $\rho$-
meson exchanges are crucial for the formation of $\Sigma_c^{(*)}\bar{D}^{(*)}$ bound states with isospin $I=1/2$. Depending on the potential strength of the $\sigma$ exchange, there may exist very shallow bound states of $\Lambda_c\bar{D}^{(*)}$ with isospin $I=1/2$ and $\Sigma_c^{(*)}\bar{D}^{(*)}$ with isospin $I=3/2$. Our study may provide useful information for further exploring the hidden-charm pentaquarks in future experiments.
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All authors Zhi-Biao Liang, Jun-Jie Liu, Mu-Yang Chen, Xian-Hui Zhong, Qiang Zhao
High Energy Astrophysical Phenomena
Polarization of Synchrotron Emission from Rotation Powered Pulsars
Seima Saeki, Shota Kisaka and Jumpei Takata
With the launch of the Imaging X-ray Polarimeter Explorer in 2021, recent observations have provided X-ray polarization data for several rotation-powered
pulsars. To fully exploit these data, it is important to better understand the relationship between polarization properties and the magnetospheric structure. In this paper, we investigate polarization properties in the outer gap model, incorporating both outward emission and inward emission toward the rotation axis, which has not been considered previously. We find that the polarization position angle varies at the intensity peaks, typically accompanied by a high polarization degree, as is in the case for outward emission. Moreover, the variation in the polarization position angle tends to exceed 50 degrees when the intensity peaks of outward and inward emissions overlap, compared to cases with only outward emission. We compare the polarization model including inward emission with IXPE observations. For example, for PSR B1509-58 where inward emission is proposed to be dominant in the outer gap model, we find that observed PA swing prefers a line of sight from the southern hemisphere rather than the northern hemisphere.
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Mathematical Physics · Cross-listed from math.PR
Classification of commutation relation for multi-radial SLE
Chongzhi Huang and Hao Wu
Locally commuting multiple radial Schramm-Loewner evolutions ($\mathrm{SLE}_{\kappa}$) are encoded by partition functions satisfying the radial Belavin-Polyakov-Zamolodchikov (BPZ) equations and a conformal Ward identity with spectral parameters $\lambda,\nu\in\mathbb{R}$. For $\kappa>0$ and $\lambda\in\mathbb{R}$, we show that the solution space of the radial BPZ system has dimension $2^n$, where $n$ is the number of variables. We then determine all admissible Ward parameters $\nu$ and the exact dimensions of the subspaces selected by the conformal Ward identity, covering both generic and degenerate cases. The classification reveals a parity difference: nonzero rotation-invariant solutions exist for every $\lambda$ when $n$ is even, but only at finitely many exceptional values when $n$ is odd. When $0<\kappa\leq4$, $\lambda>0$ for odd $n$ or $\lambda>-3/2$ for even $n$, we construct a basis of positive solutions using multiple SLE, providing global realizations of the locally commuting SLEs. At $\kappa=4$, we identify a family of explicit solutions as partition functions for level lines of a Gaussian free field with suitable boundary data and interior singularities.
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Astrophysics of Galaxies
Kinematics of the System of Young Open Clusters based on Gaia DR3 Data
A.K.Dambis and A.S.Rastorguev
We use a kinematical model including circular rotation of the Milky-Way disk incorporating effects produced by a spiral density wave with constant radial and vertical components of the velocity dispersion tensor and adopted
solar Galactocentric distance R_0=8.277kpc (inferred by
GRAVITY collaboration in 2022) to derive the velocity field parameters for a sample of 2384 open clusters from the Hunt and Reffert (2024) catalog having ages no greater than 100 Myr almost all of which reside at Galactoaxial distances between 5 and 14 kpc. We estimate the velocity-field parameters using maximum-likelyhood method and the affine-invariant variant of the Markov chain Monte-Carlo method proposed by Goodman and Weare (2010) with both methods yieilding almost identical parameter values. The inferred rotation curve, on the whole, is consistent with the results based on our kinematical analysis of a sample of
Galactic masers. We find the linear rotation velocity at the
solar distance to be V=242.3+/-1.1~km/s; it reaches its maximum V~244 km/s at Galactoaxial distance of about R_g~7 kpc followed by a slow and smooth decline with V~227 km/s at R_g=14 kpc. The inferred radial and vertical components of the velocity dispersion tensor are (sigma U_0, sigma W_0)~(10.63+/-0.15, 4.56+/-0.15) km/s. We find the pitch angle and the phase of the Sun for a four-armed spiral pattern to be i~-11.7+/-0.3 degrees and chi_0~138+/-5 degrees, respectively, and the amplitudes of radial and tangential perturbations, f_R=-3.0+/-0.4 and f_{theta}=-3.1+/-0.4 km/s, respectively.
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Superconductivity
Vortex-mediated spin current injection into two-dimensional superconductor NbSe2
Meng Yang, Xiaolong Yin, Jingjing Liu et al. (+7 more)
Injection of pure
spin current into
superconductors remains a major challenge in superconducting spintronics. Previous studies have primarily focused on
spin-polarized quasiparticles and
spin-triplet supercurrents, while
vortices, ubiquitous topological defects in type-2
superconductors, have been theoretically proposed as alternative carriers of
spin angular momentum, yet direct experimental evidence is still lacking. Here, we report the
vortex-mediated
spin current injection in NbSe2/LiAl2Fe3O8(LAFO)
bilayer, an Ising
superconductor/ferrimagnetic
insulator heterostructure. Under an out-of-plane temperature gradient and an in-plane
magnetic field, the NbSe2/LAFO
bilayer shows a pronounced thermoelectric peak near the upper critical
magnetic field, which has the opposite sign to the conventional
vortex Nernst signal observed in a single-layer NbSe2. The sign reversal suggests that the
vortex flow induced by
spin current injection is opposite to the flow driven by the temperature gradient, which is consistent with theoretical mechanisms including
spin-vorticity transmutation and the inverse
vortex spin Hall effect. By mapping the field temperature phase diagram, we reveal that the
spin current injection occurs exclusively in the
vortex liquid phase of NbSe2. Absence of the thermoelectric signal above the superconducting transition temperature further rules out the quasiparticle contribution. Our results establish
vortices as efficient carriers of
spin information in
superconductors, opening a new route towards
vortex-mediated superconducting spintronic devices.
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All authors Meng Yang, Xiaolong Yin, Jingjing Liu, Yifeng Chen, Qinwu Gao, Hongxing Zhu, Danni Huang, Lang Chen, Shuo-Ying Yang, Junxue Li
Optics
Voltage-Current-Emission Framework of Time-Resolved Electroluminescence
Hui Bao, Longjia Wu, Yanan Guo et al. (+3 more)
Time-resolved electroluminescence has been a central methodology in the development of LED devices. However, it still lacks quantitative theoretical descriptions of time-resolved electroluminescence. By combining the equivalent
circuit models of
semiconductor devices and the carrier dynamics of electroluminescence processes, we here developed a Voltage-Current-Emission framework to illustrate time-resolved electroluminescence from the pulse voltage as input, to injection current and finally generate electroluminescence as output. The features of different LED devices can be quantitatively interpreted, confirming the universal applicability across LEDs with different materials and device structures. Importantly, the curves of time-resolved electroluminescence can be simulated to quantitatively describe the dynamics of current and carriers of LED operation. In all, the Voltage-Current-Emission framework offers theoretical guidance for achieving advanced LED devices for AI technology.
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All authors Hui Bao, Longjia Wu, Yanan Guo, Jianchang Yan, Ying Wang, Haizheng Zhong
Mathematical Physics · Cross-listed from math.QA
Unitary TQFTs, unitary disk-like $n$-categories, and higher Hilbert spaces
Greyson Wesley
We introduce the notion of a
unitary disk-like $n$-category, which is a disk-like $n$-category equipped with a reflection structure and a sphere trace inducing positive-definite pairings. Since a finite
unitary disk-like $n$-category is defined to be the local field data of a fully extended $(n+1)$D
unitary TQFT, we propose a complete finite
unitary disk-like $n$-category as the definition of a finite $(n+1)$-
Hilbert space for all $n$. For $n=1$ and $n=2$ we verify this proposal, proving that complete finite
unitary disk-like 1- and 2-categories are isometrically equivalent to finite 2- and 3-
Hilbert spaces respectively, and that these equivalences are functorial. For $n=1$ we recover a
unitary refinement of Schommer-Pries' classification of oriented $(1+1)$D TQFTs in terms of $\mathrm{H}^*$-Morita equivalence classes of $\mathrm{H}^*$-
algebras, and for $n=2$ we categorify this to classify oriented $(2+1)$D
unitary TQFTs by $\mathrm{H}^*$-Morita equivalence classes of $\mathrm{H}^*$-multifusion categories. Along the way, we investigate fully incomplete 3-
Hilbert spaces, prove a strictification result for pivotal dagger 2-categories, and define functors and higher transformations between disk-like $n$-categories.
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General Relativity and Quantum Cosmology · Cross-listed from math.DG
Spacetime Positive Mass Theorem with Boundary for Multiple Time Dimensions
Changwen Fang
We prove a positive mass
theorem for one-ended asymptotically flat
spin initial data with multiple time directions and a smooth compact boundary. Assuming the trace-norm dominant energy condition and pairwise commutativity of the second fundamental forms, a fixed auxiliary time direction on each boundary component determines a local chirality condition. We identify the surviving mixed boundary term and obtain the inequality $E\geq\|\mathcal P\|_{\mathrm{tr}}$ under the boundary condition $H+\operatorname{tr}_\Sigma k^T+\|\mathcal Q_T\|_{\mathrm{tr}}\leq0$. The proof constructs a Dirac–Witten harmonic spinor in an affine energy space and evaluates the mass identity by approximation. We also establish the pointwise sharpness of this boundary condition for the fixed projector and give two-time data with a nonzero mixed boundary term.
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Quantum Physics
Local Optimality Does Not Compose: Invariant Simplices and the Complexity of Shared Probabilistic Automata
Yixin Zhao
Probabilistic models are often constructed separately for different test suites and then expected to share a single latent dynamical system. We study bounded-state shared realization for probabilistic automata from finite partial trace specifications. A shared realization uses one normalized automaton with named initial distributions, a common family of row-
stochastic letter-transition
matrices, and one final output vector. We compare it with separate local realizations and a labelled query-specific static relaxation. Local and labelled query-specific static optima need not compose. For every $k,L\ge1$, we construct finite partial specifications for which each individual specification and the labelled query-specific static relaxation have minimum state count $k$, whereas every exact shared realization requires exactly $k(L+1)$ states. The factor $L+1$ reflects the prefix progress that must be tracked by a single shared transition family. In the linear-rank-tight calibrated regime, the existence of an exact $k$-state shared realization is equivalent to finding a $(k-1)$-simplex containing the root responses, contained in the response polytope, and forward-invariant under every single-letter affine update. For finite rational specifications, exact shared realization with at most $K$ states is $\exists\mathbb{R}$-complete, while distinguishing zero minimax defect from inverse-
polynomial defect is $\mathsf{PromiseNP}$-complete. Both classifications hold over a fixed five-letter alphabet when the local and labelled query-specific static optima already equal $K$. They remain valid with Boolean final output vectors, and the robust gap persists over the full cube $[0,1]^d$. Thus the hardness arises from shared word composition.
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Mesoscale and Nanoscale Physics
Qinwu Gao, Andi Cong, Bokai Liang et al. (+6 more)
Long-distance transport of
magnon spin currents in
antiferromagnetic (AFM)
insulators has attracted tremendous
attention recently, however, the AFM
magnon spin relaxation mechanisms remain elusive. Here, we report that the Dyakonov-Perel-type
magnon spin relaxation mechanism governs the
spin current transport along the easy axis in two prototypical uniaxial AFM
insulators, Cr2O3 and alpha-Fe2O3. First, an over 450% enhancement of the first-harmonic nonlocal signal induced by a
magnetic field is observed prior to the
spin-flop transition, which can be well-interpreted by our model incorporating Dyakonov-Perel-type
magnon spin relaxation. Secondly, we find that the
magnon spin diffusion length in both
crystals increases with
magnetic field and saturates at fields above 0.8 T, consistent with our model. Finally, the temperature dependence of the zero-field
magnon spin diffusion length in both AFM
insulators can be qualitatively explained through our model. These findings are valuable for the development of low-dissipation
antiferromagnetic spintronic devices.
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All authors Qinwu Gao, Andi Cong, Bokai Liang, Meng Yang, Jingjing Liu, Lang Chen, Shiwei Wu, Ka Shen, Junxue Li
Mathematical Physics
Reconstructability of Inverse Problems under Symmetry: Separating Structural, Effective, and Physical Upper Bounds
Isshin Arai
In our previous work we introduced the Reconstruction Dimension, an upper bound on the reconstructable degrees of freedom determined solely by the
symmetry. In actual physical systems, however, the state quantities are generated through physical processes $P_o$ induced by the cause $O$. The state space is therefore often degenerate, and the upper bound determined by the representation-theoretic structure is not reached. This calls for a distinction between the upper bound determined solely by
symmetry and the one realized after the physical process. We therefore introduce a three-level structure of upper bounds: the Structural, Effective, and Physical Reconstruction Dimensions (SRD, ERD, PRD), determined respectively by the representation-theoretic structure of the intermediate space, by the concrete design of the reconstruction map, and by the degeneracy of the state space under the physical process $P_o$. For each irreducible component they form the hierarchy $\mathrm{SRD}\ge\mathrm{ERD}\ge\mathrm{PRD}$, so that the two gaps identify at which level reconstructability is lost. The framework is illustrated through two contrasting systems: the orientation dynamics of flake-like particles, where the cause is a velocity gradinet, and the two-body problem, where the cause itself is defined through the
symmetry. This paper provides a concrete framework for reconstruction in physical inverse problems.
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Earth and Planetary Astrophysics
Delayed Methane Detection in 3I/ATLAS: GCR-Driven Subsurface Stratification and Interstellar Exposure Age Constraints
Akshat Rawat and Kinsuk Acharyya
Interstellar comet 3I/ATLAS shows unusual volatile activity, including strong H$_2$O, CO, and CO$_2$ production and a delayed post-perihelion detection of CH$_4$. In this work, we investigate the delayed CH$_4$ detection in an H$_2$O, CO$_2$, and CO ice
matrix using a shape model coupled with a thermophysical
nucleus model that incorporates interstellar processing by
Galactic Cosmic Rays. We track the sublimation, trapping, depletion, and release of these volatiles as a function of heliocentric distance and explore the relevant parameter space through 12000 model runs to identify viable combinations of
primordial volatile inventory and effective GCR exposure age that reproduce the observed production rates of these volatiles. The viable models favour a volatile-rich
primordial inventory consistent with formation in an ultra-cold ($T < 20$ K) region beyond the CO snowline, followed by an effective GCR processing exposure of 0.87–3.1 Gyr during interstellar passage. GCR processing produces a continuous compositional gradient and converts part of the CO reservoir into secondary CO$_2$ and depletes near-surface CH$_4$ through radiolytic conversion. The delayed CH$_4$ detection can be explained by the survival of CH$_4$ trapped within the deeper H$_2$O
matrix and its subsequent release as subsurface heating progresses after perihelion. The timing of CH$_4$ sublimation can be used to estimate the effective GCR processing age of 3I/ATLAS. The posterior distributions also reveal a degeneracy between
primordial dust content and GCR exposure, where
dust-rich, weakly processed and ice-rich, strongly irradiated evolutionary pathways produce processed subsurface layers with similar thermophysical properties.
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Cosmology and Nongalactic Astrophysics
Probing submillimeter number counts below the confusion limit: extreme-value statistics of the P(D) distribution and its modulation by gravitational lensing
Kaustuv Basu, Andrea Guerrero and Frank Bertoldi
The shape of the submillimeter
galaxy number counts below the confusion limit is a key record of
cosmic star formation but is accessible only statistically, through the one-point distribution of map surface brightness, $P(D)$. Classical $P(D)$ analysis compresses the counts into flux-integrated constraints and requires a full instrument forward model. We introduce an extreme-value-theory analysis of the confusion $P(D)$ tail: the peaks-over-threshold formalism, in which exceedances above a threshold $u$ follow a generalized Pareto distribution (GPD). The GPD shape parameter $\xi(u)$ is a flux-resolved, normalization-free readout of the local logarithmic slope of the counts, and its gravitational-
lensing modulation $\Delta\xi(u)$ probes their local
curvature. We derive analytic relations for both, validate them with end-to-end simulations, and apply the method to Planck 857 GHz maps and the Herschel/SPIRE 350 $\mu$m map of GAMA-09. At Planck's 5' resolution the tail reflects the bright, clustered sky rather than the faint counts, though the background alone excludes the single power-law count model. At SPIRE resolution $\xi$ rises markedly with threshold, consistent with the strongly lensed bright population (a first detection of
lensing in a $P(D)$ tail), and the bright-masked map favors the Schechter model. Behind
galaxy clusters we set the first calibrated upper limits on $\Delta\xi(u)$. CCAT/FYST should separate the count models directly, but a cluster-
lensing detection needs more $10^{15}\,M_\odot$ clusters than the sky contains. The GPD tail statistic thus discriminates the functional form of the counts at fluxes of order the threshold, below the detection limit, invariant to map mean, gain and count normalization, and robust to clustering;
lensing supplies a calibrated ruler for count features, whose detection awaits deep, high-resolution surveys of massive clusters.
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Astrophysics of Galaxies
Early steps in the hierarchical assembly of a Milky Way-mass galaxy 1 Gyr after the Big Bang
Yoshihisa Asada, Marcin Sawicki, Guillaume Desprez et al. (+14 more)
We report JWST observations of a $z_{\rm spec}=5.196$ compact group of three strongly lensed low-mass
galaxies ($M_\star \sim 10^{6-7} M_\odot$ each) whose small line-of-sight velocity offsets (from $-120\pm100$ to $+160\pm110$ km s$^{-1}$) and projected separations ($\sim2$ kpc) suggest that they are undergoing merging. On the basis of abundance-matching arguments, the trio appear to be destined to evolve into a Milky Way-mass
galaxy by the present day. Our spectrophotometric analysis suggests that the
stellar mass growth of this system is not simply just due to the merging of its components; rather, it is being dramatically enhanced by intense bursts of
star formation. Presumably initiated by tidally-induced gas inflows, these
star-forming bursts boost the mass growth $2.6\pm0.5$ times that expected in straightforward merging of the existing
stellar masses. These spectroscopic observations thus not only demonstrate that hierarchical assembly remains a viable formation channel in the early assembly phases of present-day massive
galaxy, but also that interaction-induced bursts of
star formation are a major accelerator of this assembly process.
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All authors Yoshihisa Asada, Marcin Sawicki, Guillaume Desprez, Jon Judez, Marusa Bradac, Kartheik Iyer, Nicholas S. Martis, Adam Muzzin, Gael Noirot, Ghassan T. E. Sarrouh, Chris J. Willott, Jacqueline Antwi-Danso, Seiji Fujimoto, Danilo Marchesini, Vladan Markov, Luke Robbins, Visal Sok