Earth and Planetary Astrophysics
NGTS-39 b: A 58 d transiting warm Jupiter in an eccentric orbit
Ioannis Apergis, Daniel Bayliss, Solène Ulmer-Moll et al. (+53 more)
We report the discovery and characterisation of NGTS-39 b (TIC 453147896 b), a warm Jupiter transiting a Sun-like
star on a 58.2 day, eccentric (e = 0.386 +/- 0.019) orbit. NGTS-39 b was first identified from a TESS single-transit event, and subsequently confirmed with NGTS photometry and radial-velocity measurements from CORALIE and HARPS. The host
star is a bright (Tmag = 11.02) F9
dwarf with an effective temperature of Teff = 6053 +67/-30 K. NGTS-39 b is a Jupiter-sized gas
giant with a radius of 1.088 +/- 0.012 RJ and a mass of 1.467 +/- 0.081 MJ. Its
equilibrium temperature is 519 +6/-5 K, placing it between short-period hot Jupiters and cold, Jupiter-like
giants. The high orbital eccentricity and intermediate
equilibrium temperature of NGTS-39 b make it a valuable test case for formation and migration models, particularly in the poorly sampled regime of long-period gas
giants. The RV data show a linear trend of gamma dot = -17.75 m s^-1 yr^-1, which indicates the presence of an outer companion. The discovery of NGTS-39 b contributes to the small but growing population of transiting warm Jupiters with P > 50 days orbiting bright
stars.
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All authors Ioannis Apergis, Daniel Bayliss, Solène Ulmer-Moll, Samuel Gill, Toby Rodel, Matthew Battley, Paul Benni, Allyson Bieryla, James A. Blake, Andrea Bonfanti, François Bouchy, Edward M. Bryant, Matthew R. Burleigh, Samuel J. Carlier, Sarah L. Casewell, Hritam Chakraborty, Alastair B. Claringbold, Karen A. Collins, Benjamin D. R. Davies, Xavier Dumusque, Troy A. Edkins, Fintan Eeles-Nolle, Jo Ann Egger, Jorge Fernández Fernández, Marcelo Aron Fetzner Keniger, Pedro Figueira, Michael R. Goad, George Harvey, Faith Hawthorn, Melissa J. Hobson, Mathilde Houelle, Giovanni Isopi, Timour Jestin, Alicia Kendall, Monika Lendl, Daniel Lewis, Isobel Lockley, Franco Mallia, James McCormac, Morgan A. Mitchell, Lucile Mignon, Hugh Osborn, Angelica Psaridi, Alex Romanec, Suman Saha, Amber Sedgley, Sérgio Sousa, Neil Thomas, Stéphane Udry, Christopher Watson, Richard G. West, Thomas G. Wilson, Peter J. Wheatley, Jamie T. Williams, Aldo Zapparata, Krzysztof Sz. Zieliński
Chemical Physics
On the Symplectic Propagation of the Spin-MInt Algorithm for Non-Adiabatic Quantum Dynamics
James R. Rampton, Lauren E. Cook and Timothy J. H. Hele
Mapping methods are often used for the numerical simulation of nonadiabatic systems by propagating classical mapping variable trajectories. A recently popularised mapping method is
spin-mapping, whose mapping variables arise from
quantum mechanical operators with
symmetries described by a Lie-Poisson
algebra. Simulating the classical-like dynamics of
spin-mapping systems accurately is generally challenging, with many methods unable to preserve the underlying
geometric structure of the
symplectic form. The
Spin-MInt
algorithm is a recently proposed
algorithm propagating
spin-mapping variables, with a direct proof of symplecticity existing only for 2 electronic states. Here, we directly prove the symplecticity of the
Spin-MInt
algorithm for a general $K$ electronic states. A review of the
symplectic nature of coadjoint orbits of the $\mathfrak{su}(K)$ Lie-Poisson
algebra provides the framework needed to understand symplecticity of the
Spin-MInt
algorithm in this general case. The symplecticity of the method on the associated coadjoint orbit is then shown for what we believe to be the first time via an explicit verification of the symplecticity condition $\mathbf{MJ}\mathbf{M}^\textrm{T}=\mathbf{J}$ exploiting the Lie-Poisson structure of the system. To our knowledge, this is the first time the monodromy
matrix for the
Spin-MInt
algorithm has been explicitly stated using canonical coordinates on the coherent state
manifold for a general number of states. We hope that this will assist the development of classical-like
spin-mapping methods which might utilise elements of the monodromy
matrix, and inform future work on similar
symplectic algorithms for coupled and uncoupled Lie-Poisson systems.
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Quantum Physics
Undamped Modes in an N-Qubit Heisenberg Chain with Collective Dissipation
Chun Hei Leung
We investigate the undamped behaviors in a
spin-1/2 Heisenberg chain coupled with an environment via collective
spin jump operators. Using the Bethe ansatz basis, we show that undamped modes exist for any chain length N >= 3. These modes remain robust against variations in the system parameters, including the specific form of the collective dissipation, and the external field. Exploiting the Bethe ansatz solution, we further characterize the number of undamped modes and their oscillation frequencies, uncovering long-lived coherent dynamics in open integrable
quantum systems.
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Space Physics
Energetic particle-mediated interplanetary shocks observed by Solar Orbiter
D. Trotta, D. Lario, B. Reville et al. (+10 more)
Context: In collisionless shocks, energetic particles can carry sufficient pressure to modify the upstream
plasma and the shock structure itself, a regime often invoked in theories of
cosmic-ray acceleration but rarely observed in the heliosphere. Aims: We find and characterize {interplanetary} IP shocks where energetic particles dynamically dominate the upstream pressure. Methods: We analyze IP shocks observed by
Solar Orbiter inside 1 au and compute the energetic particle pressure $P_{EP}$ from
proton measurements above 10\,keV, comparing it with the upstream thermal $P_{Th}$ and
magnetic $P_{B}$ pressures. Results: We identify four shocks for which $P_{EP} \geq P_{Th} + P_B $. These events correspond to strong and fast shocks in the high-Mach-number tail of the
Solar Orbiter shock population. In several cases the $P_{EP}$ increase coincides with a decreasing upstream bulk flow speed in the shock frame, and the resulting particle-mediated foreshocks extend up to $\sim10^5$ {ion inertial lengths} $d_i$. The extent of such energetic particle dominated region depends on shock geometry. Conclusions: These observations provide evidence that accelerated particles can dynamically modify interplanetary shocks. They highlight the importance of the coupling between energetic particles, upstream fluctuations, and shock structure for understanding particle acceleration at collisionless shocks.
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All authors D. Trotta, D. Lario, B. Reville, S. Raptis, O. Pezzi, H. Hietala, P. Mostafavi, J. Giacalone, R. F. Wimmer-Schweingruber, P. Kuehl, A. Kollhoff, D. Turner, D. Burgess
Nuclear Theory
Probing hot QCD medium with heavy quarkonium in small and large collision systems
Jiamin Liu and Baoyi Chen
The yield ratios of different heavy-quarkonium states serve as sensitive probes of final-state interactions in relativistic
nuclear collisions, because common cold-
nuclear-matter effects are expected to be substantially reduced in these ratios. To quantify hot QCD medium effects in small collision systems, such as
proton-
nucleus collisions, we employ a time-dependent Schrodinger equation framework to consistently simulate the real-time
evolution of both bottomonium and charmonium states in the presence of in-medium complex heavy-
quark potentials. In p-Pb collisions at sqrt(sNN) = 8.16 TeV, our model successfully describes the observed suppression in the yield ratios of excited-to-ground states, specifically Upsilon(nS)/Upsilon(1S) and psi(2S)/J/psi, as a function of charged-particle multiplicity. This agreement supports the formation of a transient, hot QCD medium in small systems. Furthermore, the framework is employed to study the ratio of bottomonium
nuclear modification factors in sqrt(sNN) = 5.02 TeV Pb-Pb collisions, where hot medium effects become stronger. By establishing a unified description across two distinct heavy-
quark flavors and different collision systems, our study indicates that the yield ratio of bottomonium states serves as a comparatively clean probe of the hot QCD medium generated in small collision systems.
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Optics
Four-channel prototype using coherent combining of ultrashort laser pulses for dipole configuration approximation
Konstantin Burdonov, Mikhail Zolotavin, Alexey Sidnev et al. (+10 more)
This paper presents a four-channel prototype system for the
geometric combining and coherent addition of tightly focused femtosecond
laser radiation into a standing-wave field configuration. A stabilization system for beam pointing and relative phase of the four optical channels has been implemented, and its performance has been experimentally demonstrated. To characterize the standing-wave electromagnetic field distribution at the main focus of the system, an original measurement technique based on a fiber subwavelength optical probe has been employed. This work has been conducted in support of the exawatt-scale XCELS project.
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All authors Konstantin Burdonov, Mikhail Zolotavin, Alexey Sidnev, Evgeny Blinov, Alexander Kotov, Sergey Perevalov, Artem Korzhimanov, Ivan Mukhin, Alexey Pestov, Mikhail Starodubtsev, Efim Khazanov, Andrey Shaykin, Alexander Soloviev
General Relativity and Quantum Cosmology
Nonlocal correlations of fermionic entanglement in the spacetime of Einstein-Gauss-Bonnet black hole
Yifei Xu, Yanjun Chen, Qi Xiao et al. (+1 more)
The investigation of nonclassical correlations in curved spacetimes offers key insights into the intersection of
quantum information theory and gravitational physics. This paper studies two nonlocal correlation measures, non local advantage of
quantum coherence (NAQC) and Bell nonlocality (BN) in a $d$-dimensional spherically symmetric Einstein-Gauss-Bonnet (EGB) black hole spacetime. We consider two observers (Alice and Rob) initially sharing a maximally entangled Bell state: Alice freely falls into the black hole (inertial Kruskal frame), while Rob accelerates outside the horizon (non-inertial Schwarzschild-like frame). The Unruh-Hawking effect modifies Rob's field modes, requiring Bogoliubov transformations to relate the two frames. We derive the mixed bipartite density
matrix for fermionic fields and analytical expressions for NAQC and BN, which depend on Hawking temperature (itself governed by $\alpha$, $d$, and $r_h$). Our results show both correlations degrade monotonically with increasing Hawking temperature, confirm the NAQC-BN hierarchical relationship persists in EGB spacetime, and highlighting the impact of high
curvature corrections on
quantum resources.
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All authors Yifei Xu, Yanjun Chen, Qi Xiao, Xiaolong Gong
Quantum Physics
Idling error suppression through gate scheduling
Hoiki Madison Liu, Kazunori Maruyama, Hirotaka Oshima et al. (+1 more)
Achieving high-precision
quantum computation requires effective suppression of idling errors that occur when
qubits remain inactive during waiting periods within a
quantum circuit. Conventional mitigation techniques, such as dynamical decoupling, suppress decoherence by periodically refreshing
quantum states through the insertion of additional control gates. In this paper, we propose an alternative approach that suppresses idling errors through
quantum circuit scheduling without introducing any additional gate operations. By appropriately adjusting the execution timing of
quantum gates with scheduling flexibility, we demonstrate through both numerical simulations and hardware experiments that the overall computational accuracy can be significantly influenced and, in many cases, improved. In addition, we analytically derive the density-
matrix evolution under idling noise and provide a theoretical framework that explains the observed behavior.
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All authors Hoiki Madison Liu, Kazunori Maruyama, Hirotaka Oshima, Shintaro Sato
Quantum Physics · Cross-listed from cs.SE
Benchmarking Quantum Software Testing with Scalable Quantum Programs
Yuechen Li, Minqi Shao, Xiyuan Li et al. (+2 more)
Quantum software testing (QST) checks whether
quantum programs behave according to their intended specifications. A key requirement for QST research is a
benchmark that supports rigorous empirical evaluation on programs that are testable and better reflect current software development practices. However, existing studies heavily rely on small hard-coded or
circuit-level
benchmarks, while available
quantum programs are scattered across repositories without clear selection criteria, which limits fair comparison and systematic reproducibility. To this end, we present Qolumbina, a
benchmark infrastructure for controlled QST experiments on scalable
quantum programs. Qolumbina curates 40 programs from open-source repositories, turns them into test-ready subjects through systematic selection, refactoring, specifications, test case examples, unit tests, and standardized interfaces. We also propose QST-oriented criteria to characterize
quantum programs along functionality, output behavior, development complexity, and
quantum-specific execution complexity. Using these criteria, our empirical study shows that Qolumbina covers diverse testing-relevant properties and supports scalability analysis beyond fixed-size
circuit benchmarks. Through controlled experiments with two recent QST approaches, we demonstrate the feasibility of using Qolumbina for execution-cost and fault-detection studies, and highlight backend-dependent effects that can influence QST result interpretation.
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All authors Yuechen Li, Minqi Shao, Xiyuan Li, Jianjun Zhao, Kai-Yuan Cai
High Energy Physics (Phenomenology)
One-loop proton decay from Peccei-Quinn symmetry
H. B. Câmara
We promote the accidental $B+L$
symmetry of the Standard Model to a Peccei-Quinn (PQ)
symmetry while realizing spontaneous
proton decay radiatively. The PQ anomaly sector consists of vector-like
quarks (VLQs), providing a Kim-Shifman-Vainshtein-Zakharov-type
axion solution to the strong CP problem. After spontaneous PQ breaking, a residual $\mathcal{Z}_2$
symmetry remains, which forbids tree-level
proton decay. The VLQs required to generate the QCD anomaly, together with scalar mediators, odd under the residual $\mathcal{Z}_2$, induce one-loop
proton decay through the effective operator $u_R u_R d_R e_R$. We study its ultraviolet completions, featuring distinct vector-like
fermion and scalar representations, and show that the resulting models lead to distinct predictions for the
axion-to-
photon coupling, testable in helioscope and haloscope experiments. We investigate
proton and
neutron decay pheneomenology focusing on the channel $p \rightarrow e^+ \pi^0$. We also discuss
axion dark matter in pre- and post-inflationary cosmology.
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Statistical Mechanics
Sandpile Models on complex networks
Komlan Fiagbe, Jean-François de Kemmeter and Timoteo Carletti
We investigate the sandpile model on complex networks by developing a branching-process framework that explicitly incorporates dissipation during avalanche propagation. Unlike classical branching descriptions, which assume conservative transport and locally tree-like independence, the present approach introduces grain-loss effects directly into the offspring distribution, yielding generalized generating functions for dissipative avalanche dynamics. In the dissipative regime, avalanche-size distributions acquire exponential cutoffs while preserving
topology-dependent scaling behavior. Numerical simulations confirm the theoretical predictions on sparse random networks and reveal systematic deviations in highly structured
topologies. In particular, by using Holme-Kim clustered scale-free networks, we show that increasing clustering continuously lowers the avalanche exponent and enhances the probability of large cascades, demonstrating that short cycles generate strong correlations that invalidate the classical independent-branch approx imation. Surprisingly, trees also exhibit substantial deviations from power-law because low edge density and the abundance of leaves constrain avalanche propagation. These results show that dissipation, clustering, and sparse connectivity fundamentally reshape avalanche size distribution of the sandpile model on networks and establish quantitative limits for branching-process descriptions of avalanche dynamics.
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Materials Science
A depth resolved investigation of hydrogen uptake in carbon based nanostructures by soft-to-hard photoemission spectroscopy
Orlando Castellano, Alice Apponi, Luca Cecchini et al. (+11 more)
Hydrogen chemisorption on graphitic carbon modifies the carbon orbital hybridization from sp2 to sp3, altering both structural and electronic properties. Understanding not only the lateral extent but also the depth distribution of hydrogen uptake in three-dimensional carbon architectures is essential for both fundamental studies and storage applications. To this end, we investigate here the
evolution of the C 1s core-level lineshape in nanoporous
graphene (NPG) and vertically aligned carbon nanotubes (CNTs) upon hydrogenation, exploiting soft-to-hard X-ray photoemission spectroscopy to achieve a depth-resolved analysis. Decomposition of the C 1s spectra reveals the formation of an sp3 rich overlayer, indicating hydrogen chemisorption limited to the outermost accessible surfaces in both systems. These results clarify the depth distribution of hydrogen in curved and porous graphitic networks and provide quantitative constraints on its chemisorption for carbon-based hydrogen storage applications.
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All authors Orlando Castellano, Alice Apponi, Luca Cecchini, Daniele Paoloni, Simone Ritarossi, Francesco Pandolfi, Ilaria Rago, Tien-Lin Lee, Samuel Jeong, Yoshikazu Ito, Carlo Mariani, Gianluca Cavoto, Francesco Offi, Alessandro Ruocco
Mesoscale and Nanoscale Physics
An efficient formalism for inertial spin waves: Dzyaloshinskii-Moriya antiferromagnets as case studies
De-Yun Zhao, Ri-Xing Wang, Meng-Qiu Cai et al. (+2 more)
Magnetic inertia, emerging in the ultrafast regime, supports inertial
spin waves (SWs) as novel
magnetic excitations. Despite considerable efforts devoted to inertial SWs, a systematic formalism for fully characterizing their intrinsic properties, especially chirality and polarization, is still lacking, and inertial SWs in spatially nonuniform
magnetic configurations remain poorly explored. Here, we develop a framework for calculating inertial SWs and establish a general definition of their chirality and polarization via the ellipticity angle, a unified parameter encoding frequency sign, phase difference, and elliptical axis ratio. Using this method, we systematically investigate precessional and nutational SWs in uniaxial antiferromagnets with staggered and homogeneous Dzyaloshinskii-Moriya interactions (DMIs), covering uniform collinear, canted, and spiral
magnetic configurations. The results reveal that small staggered DMI preserves
spin-wave degeneracy, whereas small homogeneous DMI lifts it. Further space-time inversion
symmetry breaking in canted and spiral structures fully removes
spin-wave degeneracy across the entire Brillouin zone. Long-wavelength nutational SWs behave as backward waves, and flat bands emerge in canted and spiral configurations near a critical inertial relaxation time. In canted and spiral configurations, nutational modes are always lefthanded whereas precessional modes are always righthanded; additionally, the dispersion spectra of the canted configuration can be derived from those of the spiral configuration via band folding. Polarization is wavenumber insensitive for uniform configurations but becomes strongly dispersive for nonuniform ones. This work advances the fundamental understanding of
magnetic inertial dynamics and provides theoretical insights for the development of ultrafast magnonic devices.
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All authors De-Yun Zhao, Ri-Xing Wang, Meng-Qiu Cai, Mikhail Cherkasskii, Peng-Bin He
General Relativity and Quantum Cosmology
Boson Stars in Teleparallel Gravity with a Nonminimally Coupled Field: The Violation of Energy Conditions and Gravitational Waveforms from EMRIs
Long-Xing Huang, Ke Yang and Yong-Qiang Wang
In this work, we investigate
boson star models within the framework of teleparallel
gravity with non-minimal coupling, and obtain static, spherically symmetric solutions for both the ground state and excited states. The results indicate that the energy density of the excited-state solutions can become negative. For these solutions, the four commonly used energy conditions are no longer satisfied. In contrast, for all the ground-state solutions we have studied, the energy density remains positive and all four energy conditions are consistently satisfied. Moreover, considering the importance of astrophysical observations, the gravitational-wave signals from Extreme-Mass-Ratio Inspirals (EMRIs) composed of these
boson stars are investigated. Our results reveal that the frequency-domain characteristic strain of these waveforms falls within the detectability range of LISA, which can provide potential evidence for distinguishing compact astrophysical objects.
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Quantum Physics
Mid-infrared pure-state quantum light source based on lithium niobate waveguides
Huang Yuhang, Wang Dongzhou, Ke Shaolin et al. (+1 more)
Mid-infrared
quantum light sources hold broad application prospects in fields such as gas sensing and infrared thermal imaging. However, currently used mid-infrared
quantum entangled light sources primarily rely on bulk periodically poled lithium niobate (PPLN)
crystals, which limits brightness and integration. This paper proposes a theoretical scheme based on lithium niobate thin films, in which 1556.9 nm pumping is used to generate entangled
photon pairs with a central wavelength of 3113.8 nm. By optimizing the waveguide structure and periodic polarization design, type-II phase matching and group velocity matching are achieved. This enables transverse electric (TE)-polarized pump input to be down converted to generate
photon pairs with TE and transverse
magnetic (TM) polarizations. Furthermore, by combining a domain arrangement
algorithm used for the customized design of polarization direction in PPLN waveguides, precise phase matching is achieved, resulting in a
quantum light source with a purity as high as 0.999 and a brightness of 6.18$\times 10^6$ cps/mW, which is three orders of magnitude higher than that of the bulk PPLN
crystal source. This study provides a promising solution for realizing high-brightness, high-purity on-chip
quantum light sources in the mid-infrared band.
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All authors Huang Yuhang, Wang Dongzhou, Ke Shaolin, Jin Ruibo
Materials Science
Transition-Metal Tailored $Ga_{2}O_{2}$ Monolayer: From Room-Temperature Gas Sensing to Chemical Scavenging
Afreen Anamul Haque and Aniket Singha
Pristine $Ga_{2}O_{2}$ monolayers suffer from poor sensitivity and weak molecular capture, limiting their application in toxic gas detection and environmental detoxification. Here, we employ first-principles density functional theory (DFT) calculations to investigate the gas sensing and scavenging properties of $Ga_{2}O_{2}$ monolayers substitutionally tailored via seven transition-metals (TM): Pd, Zn, Zr, Mo, Ag, Ti, and Pt. All TM-substituted monolayers exhibit negative formation and binding energies, negligible
lattice distortion, and structural stability in molecular dynamics simulations. Performance evaluation against eight toxic industrial and three environmental gases reveals functionalities ranging from selective, reusable room-temperature sensing to permanent molecular capture. Ag substitution exhibits exceptional selectivity for $NO$ with moderate adsorption strength (~-0.83eV), an up to eight-order-of-magnitude conductivity enhancement, besides facilitating reusable $O_2$ and $NO_2$ detection. Additionally, Pd-, Zn-, Zr-, and Mo substitutions tune selectivity toward $NO$, $NO_2$, $CO_2$, $CO$, and $O_2$. Coming to applications towards toxic gas capture, Zr- and Mo-substituted systems selectively scavenge oxidizing gases, whereas Ti and Pt act as universal scavengers. Further analysis reveals that Pd- and Ag-substituted monolayers remain selective for $NO$, while Zn substitution favors $NO_2$ detection even in ambient atmospheric conditions. Thus, these tailored $Ga_{2}O_{2}$ monolayers offer a practical platform for atmospheric monitoring and detoxification.
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Solar and Stellar Astrophysics
Research Progress on Solar Small-Scale Dynamo
Wen-Jie Jiang, Lei Ni, Chun-Lan Jin et al. (+2 more)
The small-scale
solar dynamo theory, as the core mechanism explaining the origin of the persistent, disperse weak
magnetic field in the quiet Sun regions, has made significant progress over the past three decades in the fields of observation, theory, and simulation. Breakthrough observations from high-resolution space-based and ground-based
telescopes have revealed that the quiet Sun is ubiquitously populated by highly dynamic, mixed-polarity and possibly predominantly horizontal
magnetic structures with complex
topology. These observations confirm that their total
magnetic flux is substantial, with a high and widely distributed
magnetic flux emergence rate, strongly suggesting a local dynamo effect independent of the
solar cycle and driven by intense
turbulence and convection. Theoretical studies indicate that even in the challenging low
magnetic Prandtl number ( Pm << 1) environment of the
solar photosphere and convection zone, turbulent motions can self-excitedly convert kinetic energy into
magnetic energy through the stretching, folding, and twisting of
magnetic field lines. MHD simulations have successfully reproduced observed features, demonstrating that a pure small-scale dynamo can operate efficiently and sustain
magnetic fields even in an open, stratified
solar environment incorporating realistic physical processes. Current research strongly suggests that small-scale
magnetic fields constitute the majority of the
magnetic energy in the quiet Sun and also influence coronal heating,
solar wind acceleration, and radiation distribution. This article conducts a literature review centered on observations, theoretical models, and numerical simulations of the small-scale dynamo, organizing and discussing the relevant research history and progress. Finally, it summarizes the content and provides an outlook on future research from multiple perspectives.
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All authors Wen-Jie Jiang, Lei Ni, Chun-Lan Jin, Zhi Xu, Mei Zhang
Quantum Physics
Local distinguishability of six bipartite orthogonal product states
Guang-Bao Xu, Hua-Kun Wang, Yu-Guang Yang et al. (+1 more)
It is necessary to investigate the local distinguishability of orthogonal
quantum state sets, as their adoption in protocol design helps diminish
quantum state transmission and cut operational costs. In this paper, we explore the local distinguishability of six orthogonal product states (OPSs) on any bipartite
quantum system. We classify different sets of six bipartite OPSs into eight categories by using the vectors of the numbers of pairwise orthogonality relations, where any two states are orthogonal on only one subsystem within each set. We find that these eight categories contain a total of 78 distinct cases, all but five of which are perfectly distinguishable via local operations and classical communication (LOCC). Furthermore, we discuss the local distinguishability of those five distinct cases in detail. Our work explicitly characterizes the local distinguishability of six bipartite OPSs.
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All authors Guang-Bao Xu, Hua-Kun Wang, Yu-Guang Yang, Dong-Huan Jiang
Quantum Physics
Quantum sensing of aging transitions
Huining Zhang, Yunbo Zhang, Xiaoguang Wang et al. (+1 more)
The aging transition is a critical phenomenon in which collective dynamics deteriorate as the fraction of inactive
quantum nodes exceeds a threshold, referred to as the aging transition point. Such transitions are relevant to a broad range of biological and physiological systems, and may play an important role in
quantum information processing, particularly in the stability assessment and robustness control of
quantum networks. Detecting the aging transition point is therefore crucial for predicting network breakdown, since it marks the critical threshold at which a
quantum network abruptly loses its stable active state and enters a degraded inactive phase. Here we propose a
quantum sensing strategy to locate this transition point using a single
qubit probe coherently coupled to a small subset of oscillator nodes. As the inactive fraction p approaches the aging transition point, the excited-state population of the probe becomes highly sensitive to variations in p, leading to a pronounced enhancement of the Fisher information. This critical enhancement enables high-precision estimation of the transition point. Remarkably, this enhancement survives even in the classical regime for the oscillators, where the Fisher information increases dramatically as p approaches the transition region. Our results establish a feasible route to sensing aging transitions in oscillator networks and provide a metrological perspective on critical phenomena in
quantum many-body systems.
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All authors Huining Zhang, Yunbo Zhang, Xiaoguang Wang, X. X. Yi
Quantum Physics
Compressive Spectrum Sensing via Spectral Multiplexing in Rydberg Atomic Receiver
Jun-Rong Chen, Yi-Ming Yin, Le-Bin Chen et al. (+7 more)
Rydberg-atomic receivers exhibit exceptional sensitivity yet are fundamentally constrained by the narrow instantaneous bandwidth, limiting their practical deployment in broadband scenarios. Prior approaches typically expand the bandwidth by physically broadening the atomic response, which usually requires auxiliary electromagnetic fields or stringent parameter tuning, thereby increasing overall system complexity. Here, we propose a compressive spectral multiplexing framework implemented in a waveguide-coupled Rydberg atomic receiver using a frequency-modulated local oscillator (FMLO). The FMLO creates multiple parallel sensing channels that collectively constitute a physical compressive sensing
matrix, generating multiple narrowband intermediate-frequency replicas of the input signal. Thus, a broadband microwave spectrum is projected onto a set of narrowband atomic responses. It is demonstrated that spectral information spanning a bandwidth of over 640 MHz can be effectively compressed into the intrinsic atomic bandwidth of 126 kHz, achieving a spectrum compression ratio exceeding 1000. Furthermore, these output replicas offer intrinsic measurement redundancy and facilitate signal-to-noise ratio enhancement. An approximate 10 dB gain is achieved in the required bit-energy-to-noise-power-density ratio for multi-channel communication via maximal-ratio combining. This approach requires no auxiliary fields or broadband electronics, providing a simple and scalable pathway for chip-scale
quantum receivers, latency-critical sensing, and next-generation wireless communications.
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All authors Jun-Rong Chen, Yi-Ming Yin, Le-Bin Chen, Kai Wang, Bang Liu, Li-Hua Zhang, Hao Tian, Ming-Min Zhao, Bin-Bin Wei, Dong-Sheng Ding
High Energy Physics (Theory)
Local symmetry and the dependence on extended spacetime
Keith Glennon and Peter West
We show that linearised E theory possesses a local
symmetry at low levels provided the parameters of the local
symmetry obey differential conditions that restrict their dependence on the extended spacetime. In the decomposition of E theory that leads to Siegel theory, also known as Double Field theory, we also find the analogous restrictions on the parameters. They are different to the section conditions which are universally used in this context. We also show that the dilaton equation of Siegel theory is invariant under the local
symmetry if the parameters satisfy an analogous non-linear constraint on the parameters. We argue that there is no need to impose conditions on the fields of E theory or Siegel theory.
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Quantum Physics
Partially-Blind Single-Qubit Classification over a Prototype Hybrid Quantum Network
Matteo Pasini, Tzula Benjamin Propp, Janice van Dam et al. (+4 more)
In the NISQ era, there is a need for resource-efficient proof-of-principle experiments that can be built up to genuine utility. Single-
qubit classifiers (SQCs) are small-scale hybrid
quantum-classical machines capable of performing a basic machine learning task: classifying data. In principle, these can be scaled up to many-
qubit quantum classifiers capable of
quantum computational advantage. Another type of
quantum advantage is enabled by blind
quantum computation (BQC), wherein a client may run delegated
quantum computations on an untrusted server with information-theoretic security. In this paper, we develop a framework and propose a prototype experiment for a SQC where it is known to the server that a classification is being performed, but the data and outcome stay hidden, i.e., it performs partially-blind SQC (PB-SQC). This can be integrated into a
quantum network to deliver
quantum-secured classifications to remote clients; we study this for a heterogeneous
quantum network link in which
entanglement is shared between a server and a client equipped with a multiplexed solid-state
quantum memory using
entanglement swapping. The framework we develop for PB-SQC on this setup is tested in a simulation with realistic hardware parameters on a real-world credit card transaction fraud database with classification outcomes approaching those of its equivalent classical deep-belief network. In addition, we show how a two-
qubit classifier (TQC) instead of a SQC enables verification of the computation. These results pave the way towards a short- to mid-term
quantum network offering use-case-ready
quantum applications.
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All authors Matteo Pasini, Tzula Benjamin Propp, Janice van Dam, Garazi Muguruza Lasa, Alexandre Wanick, Hugues de Riedmatten, Gustavo C. do Amaral
Materials Science
HVAF Spraying of NiTi Coatings: Microstructure, Phase Transformation and Shape Memory Behavior
Sneha Samal, Shrikant Joshi, Stefan Björklund et al. (+8 more)
Depositing various coatings on surface of engineering components with the aim to improve their performance concerning wear, corrosion, friction and thermal protection is already a standard practice. Depositing metallic NiTi shape
memory alloy coatings may be a viable alternative for hard ceramic coatings. NiTi coatings offer additional benefits originating from unique functional thermomechanical properties. However, fabrication of thick NiTi coatings turned out to be difficult. Standard electroplating and
laser cladding methods are not suitable for NiTi the most widely used
plasma spray methods tend to produce chemically inhomogeneous coatings that do not transform martensitically, cold sprayed NiTi coatings suffer from poor adhesion to the substrates. In this work we report on first ever successful fabrication of thick NiTi coatings (100-300 um) that display functional thermomechanical properties and simultaneously show very good adherence to the substrate. We used high velocity air fuel thermal spray method to fabricate NiTi coatings deposited on mild steel using four different sets of processing parameters. Chemical composition, porosity, microstructure, phase transformation and functional thermomechanical properties of the NiTi coatings were evaluated. Although the coatings contain inhomogeneous microstructure, voids,
oxide particles, high density of dislocation defects and internal stress, they undergo martensitic transformation upon cooling and or mechanical loading. As sprayed NiTi coatings need to be annealed to display functional thermomechanical properties. Despite their limited tensile strength, the coatings displayed thermal actuation in 3 point bending tests and shape
memory effects in nanoindentation and scratch tests.
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All authors Sneha Samal, Shrikant Joshi, Stefan Björklund, Mohit Chandra, Akhil Bhardwaj, Jaromír Kopeček, Stanislav Habr, Lukáš Václavek, Jan Tomáštík, Ondřej Tyc, Petr Šittner
Optics
Meshfree versus grid-based Schrödinger solvers for modeling the interactions between free-electron wave packets and light
Mitja Funk, Sebastian Merk, Caroline Lasser et al. (+2 more)
The interaction of free-electron wave packets with electromagnetic fields provides a powerful route toward coherent electron control, enabling the generation of energy combs, momentum-state superpositions, and aberration-engineered electron beams. Existing theoretical descriptions, however, often rely on eikonal or no-
recoil approximations. Here, we present a mesh-free numerical framework that directly solves the time-dependent single-particle Schrödinger equation for arbitrary electromagnetic potentials. Comparison with a
benchmark mesh-based Schrödinger solver reveals excellent quantitative agreement. By eliminating the need for spatial meshing, our method offers an efficient and scalable route for simulating electron wave packet dynamics in complex time-dependent and static electromagnetic environments, while the simulation time is significantly improved by up to 800 times faster. These capabilities establish a versatile computational tool for
quantum electron optics and free-electron-light interactions beyond eikonal approximations.
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All authors Mitja Funk, Sebastian Merk, Caroline Lasser, Marlis Hochbruck, Nahid Talebi
High Energy Physics (Theory) · Cross-listed from math.CO
Double-scaled SYK from boundary metrics of planar maps
Timothy Budd
The enumeration of planar maps with control on the boundary metric, i.e. the pseudometric induced on the outer face of the map by its bulk graph distance metric, is a difficult problem in general. However, we show that for a family of bipartite planar map models with special q-deformed face weights that arise in the physics context of the double-scaled Sachdev-Ye-Kitaev model (DSSYK) the enumeration admits a very simple answer. Encoding the boundary metric of a bipartite planar map by its so-called geodesic chord diagram, we prove that the weighted enumeration depends only on the crossing number of the chord diagram. At fixed perimeter, the induced law of the geodesic chord diagram in these planar map models coincides exactly with the chord diagram representation of the DSSYK model.
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Quantum Physics
False vacuum decay in a two-dimensional quantum spin system
Luka Pavešić, Ian G. Moss and Simone Montangero
False
vacuum decay describes the relaxation of a metastable state through the nucleation and growth of bubbles of the stable phase. Despite describing a broad variety of phenomena across different fields, the
quantum version of the nucleation theory has little experimental or numerical support. Testing its predictions is particularly important in two or more spatial dimensions, where bubble nucleation acquires its true geometrical nature. Here, we study false
vacuum decay in the
quantum Ising model in two dimensions. Through tree tensor network simulations we extract the decay rate, the effective interface tension and the critical bubble size. We compare them to new semi-classical field theory calculations, and find excellent agreement. These results provide numerical evidence that the critical-bubble picture survives in an interacting
quantum spin system in 2+1 dimensions.
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Quantum Physics
Insecurity of Measurement-Device-Independent Quantum Key Distribution
Konstantin Zaitsev and Polina Acheva
The security of practical
quantum key distribution (QKD) systems is fundamentally constrained by vulnerabilities of single-
photon detectors. Measurement-device-independent
quantum key distribution (MDI-QKD) was proposed to remove this limitation by allowing all measurements to be performed by a completely untrusted party, under the assumption that the measurement node can be treated as
adversarial but does not compromise the security guarantees of the protocol. Here we show that this assumption is insufficient under realistic
adversarial control of the measurement device. We present an attack in which an adversary exploits active control of the measurement node (Charlie) to obtain significant information about the secret key. The attack enables recovery of up to 70% of the sifted key while introducing only 5.6%
quantum bit error rate. Unlike previously reported attacks targeting specific implementations of MDI-QKD, our results demonstrate a limitation of the standard security model underlying the protocol. These findings indicate that additional constraints on the measurement-device independence assumption, or refined security analyses incorporating stronger
adversarial capabilities, are required to ensure the security of MDI-QKD in realistic scenarios.
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Fluid Dynamics
Energy transfer, Intermittency and Mixing in Shear-Driven Stratified Turbulence
Chandra Shekhar Lohani and Vishwanath Shukla
We investigate a stably stratified flow driven by deterministic Kolmogorov forcing that generates horizontal shear, using direct numerical simulations over a broad range of stratification strengths characterized by the Froude number $Fr$. As the stratification is progressively weakened, the flow exhibits a sequence of regimes: a buoyancy-dominated, strongly stratified regime, an intermediate regime characterized by Kelvin–Helmholtz instabilities and enhanced mixing, and a nearly isotropic turbulent regime. A key feature of the intermediate stratification range is the emergence of energetically significant vertically sheared horizontal flows (VSHFs), accompanied by a marked steepening of the reduced one-dimensional perpendicular kinetic energy spectra. The spectral energy transfer remains predominantly forward, although the perpendicular flux becomes negative at large horizontal scales; this apparent upscale transfer reflects anisotropic energy redistribution rather than a true inverse cascade. Strong stratification enhances intermittency, producing increasingly non-Gaussian vertical velocity fluctuations and large kurtosis associated with localized vertical bursts. The energetics-based mixing coefficient remains of order $10^{-1}$ over the parameter range investigated, with a modest enhancement near the Kelvin–Helmholtz instability regime.
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Instrumentation and Methods for Astrophysics
Pulsar Backend for 21 CentiMeter Array: Implementation of Data Acquisition and Initial Results
Yukai Zhou, Junhua Gu, Mengyao Xue et al. (+8 more)
We implemented a data acquisition system for 21 CentiMeter Array (21CMA), enabling baseband observations targeting
pulsars and fast
radio bursts. Based on the
Radio Frequency System-on-Chip (RFSoC) platform, the new backend is capable of instantaneously covering the effective bandwidth from 50 to 350 MHz, with multi-board synchronization achieved at the timescale of the sampling clock. We observed PSR B0329+54 with a single station to verify the signal path integrity; then solved phase relations of multiple station pairs using bright persistent
radio sources like Cas A and Cyg A; using these phase solutions, a multiple-station coherently beamformed observation of PSR B0329+54 was carried out, showing a signal-to-noise ratio of 699.09 for a 2.5-hour observation with eight stations, opening up a possibility of tied-array low-frequency
pulsar observations on 21CMA.
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All authors Yukai Zhou, Junhua Gu, Mengyao Xue, Faxin Shen, Jian Li, Qiuyang Fu, Cijie Zhang, Youling Yue, Weiwei Zhu, Kejia Lee, Renxin Xu
Instrumentation and Methods for Astrophysics
Current status of the High-Resolution Multi-Object Spectrograph (MOS-HR) for the Wide-field Spectroscopic Telescope
Andrea Tozzi, Anna Brucalassi, Matteo Munari et al. (+10 more)
The Wide-field Spectroscopic
Telescope (WST) is a planned 12-meter class dedicated spectroscopic facility for massive spectroscopic surveys. This paper presents the current status of Work Package 4.5, the High Resolution Multi-Object Spectrograph (HR-MOS) module. We describe the international team organization and optical design resulting from extensive trade-off studies, presenting its
evolution driven by scientific requirements and technical constraints. Design parameters derived from science cases and astronomical community requirements are detailed. Given the critical importance of mass and volume budgets, we present envelope dimensions and mass estimates for HR-MOS. The spectrograph constructive parameters are defined, including optical fiber specifications, multiplex capability, and modular architecture. Finally, we present the structural analysis addressing mechanical stability and performance requirements for this high-resolution multi-object spectrograph.
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All authors Andrea Tozzi, Anna Brucalassi, Matteo Munari, Simone D'Auria, Andrea Bianco, Giorgio Pariani, Ciro Del Vecchio, Paolo Picchi, Roland Bacon, Bernard Delabre, David Lee, Sofia Randich, Will Saunders