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Physics

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Tuesday 8 September

Classical Physics

Projection Angles of Projectiles in Sports: Qualitative Assessment of the Effects of Aerodynamic Forces or Run-Up

Kazuhiro Tsuboi

We examine two major factors that influence the optimum projection angle: aerodynamic forces and the effect of run-up. With respect to aerodynamics, we consider not only the drag but also the lift generated by spin during flight. By linearizing the equations of motion that include these forces, we derive perturbation solutions with respect to drag and lift coefficients and clarify their qualitative effects. The results show that both drag and lift reduce the optimum projection angle, with the latter exerting a stronger influence. To investigate the effect of run-up, we use an extended projection model in which the initial speed depends on the initial angle. Analysis of this model reveals that a stronger run-up increases the relative projection angle but decreases the launch angle observed from the ground. These findings provide a mechanical explanation for the release angle in shot put and the takeoff angle in long jump. The present study establishes a simple theoretical framework for clarifying the respective roles of aerodynamic and run-up effects in determining the optimum projection angles in sports.
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High Energy Astrophysical Phenomena

Revisiting EBL Constraints from Gamma-Ray Observations: A Critical Assessment and Methodological Improvements

K. Abe, S. Abe, J. Abhir et al. (+185 more)

The extragalactic background light (EBL), ranging from the infrared to the ultraviolet bands, is the second most intense photon field in the universe, surpassed only by the cosmic microwave background (CMB). It is primarily generated by starlight in galaxies, either directly or through absorption by dust and re-emission at longer wavelengths. Very high energy (VHE, $E$ > $100\,$GeV) photons can be absorbed via $\gamma \gamma$ interactions with the EBL during their propagation across cosmological distances, providing an indirect method to probe the EBL by studying its impact on the energy spectra of distant VHE sources. This paper examines the robustness of EBL constraints derived from gamma-ray data, critically assessing the assumptions made in previous studies about the intrinsic source spectra, the uncertainties of the observations and the validity of the analysis tools. We find that earlier studies likely underestimated the uncertainties in the EBL intensity constraints, underscoring the need to account for systematic uncertainties comprehensively. By employing a Monte Carlo (MC) simulation and a plausible model for unknown systematic errors, we compute more realistic uncertainties. Additionally, we discuss possible alternatives to set EBL constraints, relaxing the assumptions on the intrinsic spectra of gamma-ray sources, with the goal of achieving more robust constraints.
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All authors K. Abe, S. Abe, J. Abhir, A. Abhishek, V. A. Acciari, A. Aguasca-Cabot, I. Agudo, I. Albanese, T. Aniello, S. Ansoldi, A. Arbet Engels, C. Arcaro, T. T. H. Arnesen, A. Babić, C. Bakshi, U. Barres de Almeida, J. A. Barrio, I. Batković, J. Baxter, J. Becerra González, W. Bednarek, E. Bernardini, J. Bernete, A. Berti, J. Besenrieder, C. Bigongiari, A. Biland, O. Blanch, G. Bonnoli, Ž. Bošnjak, E. Bronzini, I. Burelli, A. Campoy-Ordaz, A. Carosi, R. Carosi, M. Carretero-Castrillo, A. J. Castro-Tirado, D. Cerasole, G. Ceribella, A. Cerviño, Y. Chai, G. Chon, A. Cifuentes Santos, J. L. Contreras, J. Cortina, S. Covino, G. D'Amico, P. Da Vela, F. Dazzi, A. De Angelis, B. De Lotto, M. Delfino, J. Delgado, C. Delgado Mendez, F. Di Pierro, R. Di Tria, L. Di Venere, A. Dinesh, D. Dominis Prester, A. Donini, D. Dorner, M. Doro, L. Eisenberger, D. Elsaesser, L. Foffano, L. Font, F. Frías García-Lago, S. Fröse, Y. Fukazawa, S. García Soto, M. Gaug, J. G. Giesbrecht Paiva, N. Giglietto, F. Giordano, P. Gliwny, T. Gradetzke, R. Grau, J. G. Green, P. Günther, D. Hadasch, A. Hahn, G. Harutyunyan, T. Hassan, J. Herrera Llorente, D. Hrupec, D. Israyelyan, J. Jahanvi, I. Jiménez Martínez, J. Jiménez Quiles, S. Kankkunen, T. Kayanoki, G. W. Kluge, J. Konrad, P. M. Kouch, H. Kubo, J. Kushida, M. Láinez, A. Lamastra, E. Lindfors, S. Lombardi, F. Longo, R. López-Coto, M. López-Moya, A. López-Oramas, S. Loporchio, L. Lulić, E. Lyard, P. Majumdar, M. Makariev, M. Mallamaci, G. Maneva, M. Manganaro, S. Mangano, K. Mannheim, M. Mariotti, M. Martínez, P. Maruševec, D. Mazin, S. Menchiari, J. Méndez Gallego, S. Menon, D. Miceli, J. M. Miranda, R. Mirzoyan, M. Molero González, E. Molina, H. A. Mondal, A. Moralejo, C. Nanci, A. Negro, V. Neustroev, M. Nievas Rosillo, C. Nigro, L. Nikolić, K. Nilsson, S. Nozaki, A. Okumura, J. Otero-Santos, S. Paiano, D. Paneque, R. Paoletti, J. M. Paredes, M. Peresano, M. Persic, M. Pihet, F. Podobnik, P. G. Prada Moroni, E. Prandini, W. Rhode, M. Ribó, J. Rico, A. Roy, N. Sahakyan, F. G. Saturni, F. Schiavone, K. Schmitz, F. Schmuckermaier, A. Sciaccaluga, G. Silvestri, A. Simongini, J. Sitarek, V. Sliusar, D. Sobczynska, A. Stamerra, J. Strišković, D. Strom, M. Strzys, Y. Suda, M. Takahashi, R. Takeishi, J. Tartera Barberà, P. Temnikov, T. Terzić, A. Tutone, S. Ubach, M. Vazquez Acosta, S. Ventura, G. Verna, I. Viale, A. Vigliano, C. F. Vigorito, E. Visentin, V. Vitale, M. Vorbrugg, I. Vovk, R. Walter, C. Walther, F. Wersig

Atmospheric and Oceanic Physics

EastAsiaClimateExtremes: An AI-Ready Dataset of Weekly Atmospheric and Oceanic Extremes over East Asia for Subseasonal Prediction Research

Miae Kim, Yun-Young Lee and Uran Chung

Despite growing interest in AI-based prediction of climate extremes, event- or label-based AI-ready extreme climate datasets remain limited, constraining efforts to systematically characterize and forecast such phenomena. To address this gap, we present EastAsiaClimateExtremes, an open dataset that provides ERA5/OISST reanalysis-based weekly extreme labels and event-based metrics for anomalously high temperature (AHT), heavy rainfall (HR), and marine heatwaves (MHW) over East Asia, together with analysis workflows hosted on GitHub to facilitate reproducibility and adaptation. The dataset is fully documented and co-registered with ECMWF S2S hindcast outputs on a common spatial grid and temporal framework, thereby enabling direct comparison between reanalysis-derived labels and dynamical model forecasts. This unified dataset serves as a reference framework for East Asian climate extreme research and AI-based subseasonal-to-seasonal prediction. It supports both quantitative characterization of the spatiotemporal occurrence of regional extremes and systematic diagnosis of S2S model skill in reproducing extreme signals. Beyond these immediate applications, the dataset enables a broader range of studies such as extreme event attribution and compound risk analysis. The accompanying analysis workflows characterize the historical statistics of reanalysis-based weekly extremes-including occurrence frequency and mean and maximum intensity-together with their climatological means and trend characteristics, and further assess the skill of the ECMWF hindcast.
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Computational Physics

Beyond Residuals: Energy based solutions of partial differential equations using scientific machine learning

Timon Rabczuk and Yizheng Wang

Energy-based approaches provide a natural and physically consistent framework for a large class of partial differential equations arising in solid and fluid mechanics, where the governing equations follow from variational principles. In contrast to residual-based physics-informed neural networks (PINNs) and their weak-form variants, which enforce the strong or weak form of the equations through loss minimization, the Deep Energy Method (DEM) directly computes the solution as the minimizer of an energy or incremental potential functional. This eliminates the need for residual weighting, avoids high-order derivatives, and enables the direct enforcement of physical constraints through the variational structure.In this work, we systematically revisit the Deep Energy Method, placing it in the broader context of physics-informed learning and variational modeling. We clarify the relationship between DEM, PINNs, and VPINNs, and identify the class of problems for which energy minimization provides intrinsic advantages in terms of stability, robustness and interpretability. Particular emphasis is placed on incremental variational formulations, which allow DEM to be applied to nonlinear, history-dependent and time-dependent problems, including phase-field fracture and dissipative systems. The variational structure underlying DEM further provides a natural foundation for optimization and inverse problems, where the energy functional acts as a physics-based constraint rather than a residual penalty. Through a series of numerical examples, we demonstrate that DEM offers a principled and effective alternative to residual-based methods for variational problems, highlighting its strengths and limitations relative to existing physics-informed approaches.
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Superconductivity

Magnetochiral anisotropy of thermally activated phase slips in noncentrosymmetric superconductors

Alex Levchenko

Resistive tails of narrow superconducting wires below the critical temperature are governed by phase slips, thermally activated near the transition and quantum at lower temperatures. We develop the theory of thermally activated phase slips in wires lacking inversion symmetry, modeled microscopically as a diffusive wire formed from a two-dimensional electron gas with Rashba spin-orbit coupling in an in-plane magnetic field. The phase-slip resistance acquires magnetochiral anisotropy: at fixed current it changes upon reversal of the field, and at fixed field upon reversal of the current, while the linear-response resistance remains field symmetric as required by Onsager reciprocity. The nonreciprocity originates from an asymmetry of the phase-slip activation barrier that is odd in both current and field. It is generated by the Lifshitz invariants of the free energy, the cubic gradient term and the momentum-odd quartic vertex, together with even gradient terms promoted to odd ones by the helical ground state, precisely the combination that determines the superconducting diode effect. The barrier asymmetry is therefore fixed by the diode efficiency of the same wire through a universal numerical ratio, with no adjustable parameters. The kinetic Lifshitz invariant, which makes relaxation and noise of the order parameter nonreciprocal, affects only the fluctuation prefactor at a parametrically subleading level. Because the asymmetry resides in the activation exponent, the magnetochiral signal is amplified relative to the diode asymmetry by the ratio of barrier height to temperature, and appears as a field-antisymmetric splitting of the exponential slopes of differential-resistance traces routinely used to identify thermally activated phase slips.
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Soft Condensed Matter

A unified description of flow-induced scission of wormlike micelles under shear and extensional flows

Yusuke Koide, Takato Ishida, Takashi Uneyama et al. (+1 more)

We investigate flow-induced scission of wormlike micelles under different flow kinematics using dissipative particle dynamics simulations of surfactant solutions in shear, uniaxial extensional, planar extensional, and biaxial extensional flows. The average lifetime of wormlike micelles is used to quantify the degree of scission. While flow-induced scission occurs in all flow types when the deformation rate is sufficiently high, the dependence of the average lifetime on the deformation rate differs among flow types. To provide a unified description, we introduce an effective extension rate determined by the velocity gradient tensor and micellar orientation. When expressed in terms of this effective extension rate, the average lifetimes obtained under all flow types considered collapse onto a single curve. These results demonstrate that a unified description of flow-induced scission requires not only the strength and kinematics of the imposed flow, but also the micellar orientation relative to the extensional direction.
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All authors Yusuke Koide, Takato Ishida, Takashi Uneyama, Yuichi Masubuchi

Quantum Physics

Transversal Fanout for Fault Tolerant Distributed Quantum Computing: Analysis and Application

Seng W. Loke

We study a resource-efficient approach for implementing logical fanout operations in fault-tolerant distributed quantum computing using transversal operations on quantum error-correcting code blocks. Logical fanout, comprising multiple controlled-NOT operations from a common control qubit to target qubits located at remote nodes, is an important primitive for distributed quantum computation but can require substantial non-local communication when implemented directly between encoded blocks. We exploit the structure of encoded blocks and the availability of transversal logical operations to construct distributed fanout circuits that reduce the required non-local operations while preserving the logical action of the fanout operation. The construction is developed for encoded quantum information and illustrated using Bivariate Bicycle (BB)-code blocks. We analyze the resulting physical gate, entanglement, circuit-depth, and ancilla requirements. The approach provides a systematic method for implementing large logical fanout operations across distributed error-corrected quantum processors. Also, we study a distributed implementation of the global gate GCZ involving logical qubits (encoded using BB-code blocks), exploiting the concurrency in transversal distributed fanouts.
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Mathematical Physics · Cross-listed from cs.IT

Finite-Modal Realization and Operator-Norm Convergence of a Source-to-Observation Electromagnetic Scattering Green Operator

Zhukang Wang, Da Li, Ruifeng Li et al. (+7 more)

Source-to-observation operators provide reusable environment-level descriptions for multi-query electromagnetic (EM) prediction and communication-mode analysis. However, in practical multiple-scattering models, these operators are represented with finitely many angular modes, and agreement for selected excitations or between successive truncation orders does not establish uniform accuracy of the full map or reliability of its singular channels. To close this gap, we formulate the environment-induced response as a scattering Green operator on fixed continuous source and observation spaces and derive an exact trace-space factorization that reconstructs the Maxwell scattered field. For fixed, pairwise-disjoint enclosing trace spheres and a well-posed collective problem, nested vector spherical wave function (VSWF) realizations converge in operator norm. A structural bound separates external modal tails from collective-resolvent sensitivity, and operator-norm convergence guarantees uniform convergence of the singular values. We further construct a finite metric core that preserves the nonzero singular values of each finite-order operator and reconstructs matched orthonormal source–field channels without introducing external-support discretization degrees of freedom (DoF) into the spectral problem. Full-wave benchmarks verify the finite-order implementation. A controlled near-resonant two-sphere study shows that adjacent-order agreement can precede resolution of the dominant high-order collective direction. It further shows that only part of the internal amplification appears in externally accessible gains and that resonance promotes a distinct high-order channel pair above an otherwise preserved low-order family. The resulting framework provides a convergent, metric-consistent finite-modal representation of multiple-scattering source-to-observation operators and their accessible channels.
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All authors Zhukang Wang, Da Li, Ruifeng Li, Jinyan Ma, Jiarun Hu, Jiahui Wang, Anqi Xia, Tengjiao Wang, Said Mikki, Er-Ping Li

Quantum Gases

Large-Chern-number flat bands, anomalous Dirac cones, and unconventional superfluidity in square-lattice systems with SU(N) non-Abelian gauge fields

Wentao Zhong and Zhongbo Yan

We study topological band structures and superfluid phases in two-dimensional square-lattice systems with homogeneous SU($N$) non-Abelian gauge fields. Starting from an SU(4) gauge-field model related to the Hofstadter model with flux $\alpha=1/4$, we show that the lowest and highest bands are isolated Chern bands that carry Chern numbers $C=-4$ and give rise to four chiral edge modes in a strip geometry. Remarkably, although the two middle bands touch and form $16$ gapless Dirac cones, their combined Chern number is $C=8$. We then generalize the construction to SU($N$) systems and reveal an even–odd structure of the band topology: when $N$ is odd, all bands are isolated and carry nonzero Chern numbers; when $N$ is even, the two middle bands touch at $N^{2}$ Dirac points, while all other bands remain isolated and topologically nontrivial. We find that the uppermost and lowermost bands become increasingly flat and their Berry curvature becomes more uniform as $N$ increases, providing a promising platform for realizing fractional Chern insulating phases. We further examine the spin-$3/2$ SU(4) model with on-site attractive Hubbard interactions, exploring its superfluid phases at partial filling. We find that the non-Abelian gauge field breaks the hidden SO(5) degeneracy of the quintet pairing and selects distinct nematic superfluid states. For fillings in the middle-band regime, the resulting spectrum can host topologically protected Bogoliubov Fermi surfaces. Our results provide a starting point for exploring both topological band physics and unconventional superfluidity in synthetic SU($N$) cold-atom systems.
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Statistical Mechanics

Speed Limit for Information Acquisition in Stochastic Learning Dynamics

Shuta Kobayashi and Andreas Dechant

Neural networks acquire internal representations through learning. In this work, we formulate stochastic gradient descent (SGD) as a Markovian stochastic process and derive a Fisher-information flow speed limit that bounds the rate at which trainable parameters can acquire information about latent variables in the data-generating process. The resulting inequality decomposes the information flow into drift and noise contributions, thereby quantifying the roles of deterministic learning forces and SGD-induced fluctuations from an information-theoretic perspective. We verify the bound in analytically tractable basis-function linear regression, where the information budget predicted by the bound reproduces the ordering and characteristic time scales with which different latent variables are encoded in the learned parameters. These results establish Fisher-information speed limits as a quantitative framework for diagnosing when and how different aspects of the data-generating mechanism are acquired during stochastic learning.
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Quantum Gases

Increase of Magnetic Trap Loading Efficiency for $^{39}\mathrm{K}$ Bose–Einstein Condensation Experiments

Yihao Cheng, Xiaoyang Shen, Weixin Li et al. (+3 more)

During the experimental sequence, a large atom number is important for the creation of high-quality Bose–Einstein condensates. We report an experimental increase of about 15% in magnetic-trap (MT) loading efficiency by optimizing the MT loading process. The loading time is much shorter than the lifetime of the atoms in the MT, which means atom loss during loading due to the finite trap lifetime can be neglected. We obtain an almost pure $^{39}\mathrm{K}$ condensate with $1.2\times10^{5}$ atoms after evaporative cooling in our optical trap.
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All authors Yihao Cheng, Xiaoyang Shen, Weixin Li, Hao Du, Hongwu Zhao, Lin Xia

Quantum Physics · Cross-listed from cs.IT

Asymptotically good binary triorthogonal codes and higher-level transversal gates

Rodrigo San-José

For each level of the Clifford hierarchy from the third level onward, we construct explicit asymptotically good binary CSS codes for which a strongly transversal diagonal rotation, followed by a correction from the preceding level, implements the corresponding logical rotation. We achieve this using algebraic geometry codes over binary extension fields and performing an alphabet reduction that translates orthogonality conditions over the extension field to binary overlap conditions. In particular, we obtain the first asymptotically good family of binary triorthogonal codes. We also give a stronger construction with worse parameters for which the strongly transversal physical rotation implements the desired logical rotation, with no subsequent correction. Finally, adapting an error-correction-based distillation protocol, our binary $T$-gate families yield direct constant-overhead $T$-state block distillation from noisy $T$-state inputs under sufficiently weak input noise and ideal stabilizer operations.
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Soft Condensed Matter

Viscoelasticity reshapes the frequency response of a rotating magnetic particle

Zhiyuan Zhao, Tingting Sun, Han Gao et al. (+3 more)

A magnetic particle driven by a rotating magnetic field undergoes a transition from synchronous to asynchronous rotation at a critical driving frequency. The asynchronous dynamics is well understood in Newtonian fluids but remains unclear in viscoelastic media. Here, we develop a theoretical description of the asynchronous rotation of a magnetic particle in a Jeffreys-type viscoelastic fluid. The particle's time-averaged angular velocity exhibits a nontrivial frequency dependence that changes from non-monotonic to monotonic as the polymer relaxation time increases. This behavior is explained by the interplay among magnetic driving, viscoelastic relaxation, and frequency-dependent viscous dissipation. We further derive an asymptotic expression that captures the non-monotonic dependence. These results clarify how solvent and polymer contributions jointly control asynchronous rotation and provide a physical basis for guiding relevant applications in complex fluids.
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All authors Zhiyuan Zhao, Tingting Sun, Han Gao, Ye Xu, Mingcheng Yang, Masao Doi

Materials Science

Pressure Evolution of Atomic Volume Systematics in Transition Metals

Masaaki Geshi and Yuichi Akahama

We investigated the evolution of the well-known parabolic dependence of atomic volume on atomic number in transition metals under extreme compression at pressures up to 400 GPa using density functional theory calculations. Our results reveal that the ambient-pressure parabolic trend transforms into a characteristic cubic-like behavior at high pressures. This evolution is attributed to the higher compressibility of bcc transition metals associated with comparatively large increases in the total energy. The present findings are discussed in relation to previous experimental observations and first-principles calculations.
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Optics

Integrated yoctosecond-precision timing detector

Jie Yang, Tong Wang, Yulin Shen et al. (+12 more)

Precise timing detection is essential for exploring ultrafast phenomena in fields ranging from free-electron lasers to ultra-high-power laser facilities. However, achieving simultaneous high resolution and large dynamic range remains a fundamental challenge, and state of the art systems are often constrained by their physical size, power requirements, and limited scalability. Here we introduce an integrated dual electro optic sub cycle timing detector (DEST) that overcomes these limitations. In a proof of principle measurement, the device resolves timing jitter as small as 11 yoctoseconds (ys, $10^{-24}$ s) at 1 MHz–equivalent to the transit time of light across two protons–while maintaining an unambiguous measurement range of 6.15 ps and a dynamic range exceeding 155 dB. The core detection unit is miniaturized to chip scale dimensions of 18 mm x 2 mm x 1 mm on a thin film lithium niobate platform, ensuring inherent stability and immunity to environmental disturbances. Moreover, the architecture naturally lends itself to massive parallelization through array integration, with the potential to push timing precision to the sub 10 rontosecond (rs, $10^{-27}$ s) level within a 1 $m^2$ footprint. This combination of extreme sensitivity, wide dynamic range, compact size, and scalability opens new avenues for detecting previously inaccessible weak signals, including those from gravitational waves, quantum vacuum fluctuations, and beyond.
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All authors Jie Yang, Tong Wang, Yulin Shen, Dehui Pan, Zhichao Chen, Ming-Yang Zheng, Bin Wang, Shaobo Fang, Yi Zhang, Ke Zhang, Jiahui Yao, Minghua Chen, Guorong Wu, Xueming Yang, Ming Xin

Optics

Topology of Photonic Time Crystals under Complex Refractive Index Modulation

Huili Lin, Zhaohui Dong, Xianfeng Chen et al. (+1 more)

Photonic time crystals, constructed by periodic modulation of electromagnetic parameters in time, hold unique topological properties. Here, we explore permittivity and conductivity co-modulated PTCs (PCM PTCs) by dynamically tuning permittivity and conductivity simultaneously of the spatially-uniform materials, and discover their distinctive non-Hermitian effects. We find that such PCM PTCs hold a global shift of the Floquet spectrum along the imaginary quasifrequency axis, which controls field amplification and decay in both momentum bands and band gaps. By further considering the temporal interface consisting of two different PCM PTCs, we can unveil the relationship between the emergence of topological edge states and momentum band inversion by analyzing the eigenstates at exceptional points. Moreover, the characteristic of the topology of PCM PTCs can also be captured from the complex Dirac mass. Our work studies the topology of PTCs in complex modulation regime, offering new opportunities for manipulating topological edge states in the time domain.
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All authors Huili Lin, Zhaohui Dong, Xianfeng Chen, Luqi Yuan

Quantum Physics

Classical Active-Space Hybrid Quantum Subspace Expansion (CASH-QSE): Quantum Corrections without Remeasuring the Classically Calculable Energy

Artur F. Izmaylov

The wave function prepared by a variational quantum eigensolver (VQE) can contain a substantial classically tractable component, yet its energy contribution is sampled on the quantum device. Representing the wave function as a combination of a classical reference and separately prepared quantum states allows the reference energy to be evaluated without quantum sampling. However, near-linear dependence among these components can amplify measurement errors and destabilize the resulting energy estimate. We introduce Classical Active-Space Hybrid Quantum Subspace Expansion (CASH-QSE), which retains a complete-active-space self-consistent field (CASSCF) reference classically and uses occupation structure to construct quantum states exactly orthogonal to the reference and to one another. The energy follows from an ordinary Hermitian eigenvalue problem without overlap measurements, while the same occupation constraints simplify the measured operators. Using full configuration interaction to guide component selection, we test CASH-QSE along H$_2$O and N$_2$ bond-stretching coordinates spanning weakly to strongly correlated regimes. The benchmarks use STO–3G for both molecules and a restricted cc-pVDZ orbital space for H$_2$O. CASH-QSE reaches chemical accuracy while limiting the largest complete measurement circuits to a few hundred all-to-all logical controlled-NOT gates. In favorable cases, it also reduces the idealized final-energy sampling cost by several orders of magnitude relative to VQE with an adaptive derivative-assembled pseudo-Trotter ansatz (ADAPT-VQE).
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Mathematical Physics · Cross-listed from math.PR

On overlap concentration in the Curie-Weiss Random Field model

Yutong Li, Juspreet Singh Sandhu and Jonathan Shi

We show that the overlaps of two independent replicas drawn from the Gibbs measure of the Curie–Weiss model with random field (CWRF) exhibit sub-Gaussian tails when the inverse temperature $ \beta < 1$ and the random field is drawn from a Gaussian distribution that makes the expected magnetization of the CWRF equal to its expected overlap in the thermodynamic limit. To show this, we prove finite-moment concentration via a rigorous Laplace approximation for a certain random rate function, and “bootstrap” it to a uniform bound for the moment-generating function of the squared overlap deviations using a sharp analysis of the associated rate function.
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Quantum Physics

Saving resources through repeat-until-success positive-operator-valued-measure measurements in quantum computation

Hefeng Wang, Sixia Yu and Hua Xiang

We present a quantum computation approach in which computation is guided by positive-operator-valuedmeasure (POVM) measurements following a given computation path in multisteps. In this approach, one ancillary qubit is coupled to a register of working qubits, and a POVM measurement is implemented effectively on the working qubits by applying a unitary operation on the whole system followed by a projective measurement performed on the ancillary qubit. Each step of the computation is a repeat-until-success procedure such that the desired state of the step is obtained deterministically on the working qubits via POVM measurements. The principle of deferred measurement states that measurements can always be moved from an intermediate stage of a quantum circuit to the end of the circuit without affecting the efficiency of the computation.We demonstrate that in our approach, by introducing intermediate measurements on the ancillary qubit in the computation process, both the number of qubits and unitary operations can be reduced polynomially, compared to the case where the intermediate measurements are deferred to the end of the computation. We also provide a method for implementation of the approach.
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Quantum Physics

Quantum-state texture measure and texture transformation

Yufan Lin, Yu Guo, Fei He et al. (+1 more)

Quantum-state texture quantifies structural irregularities of a state in a selected basis and has emerged as a valuable resource for gate characterization in universal circuits. Consequently, a class of contractive distance based texture measures and a framework for constructing convex-roof extended texture measure have been proposed. Here, we extend this theory in several directions. We examine the convertibility of a pure state to any state under texture-free operations, and fully solve the deterministic transformation problem between any two states in the qubit case. We then propose two classes of texture measures: convex-function-based measures and texture cost defined via minimal cost of texture contained in pure states. Moreover, we show that every texture monotone gives rise to a non-negative function which admits the same properties as the function used in the convex-roof extension—thus providing a converse to that construction. Our work thereby offers a relatively comprehensive resource-theoretic formulation of quantum-state texture.
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All authors Yufan Lin, Yu Guo, Fei He, Shuanping Du

Other Condensed Matter

Transport properties and topological phase transitions for a Creutz-Su-Schrieffer-Heeger ladder

K. A. González, S. Bravo, L. Rosales et al. (+1 more)

In this work, we investigate the electronic, topological, and transport properties of a Creutz-Su-Schrieffer-Heeger (CSSH) ladder. Using a tight-binding model within the Green's function formalism, we calculate the energy spectrum, local density of states (LDOS), and electronic transmission. We first determine the energy spectrum of the CSSH ladder and analyze the different topological phases present in the system, identifying one trivial phase and three distinct nontrivial regions. We then study electronic transport and show that the transmission reproduces the different topological phases through characteristic transport signatures. Finally, we derive the conditions for the emergence of non-topological flat bands and demonstrate that these bands also provide the necessary conditions for the formation of bound states in the continuum (BICs). Our results establish a direct connection between the topological properties, flat-band formation, and electronic transport in the CSSH ladder.
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All authors K. A. González, S. Bravo, L. Rosales, P.A. Orellana

Astrophysics of Galaxies

The Roman eXtreme Deep Field (RXDF)

Haojing Yan, Anton M. Koekemoer, Yue Shen et al. (+127 more)

The Roman eXtreme Deep Field (RXDF) program is one of the five General Astrophysics Survey (GAS) programs approved for observing time with the Nancy Grace Roman Space Telescope in Cycles 1 and 2. It has been allocated 386.41 hours to carry out an imaging survey to AB = 30 mag (5-sigma) over ~140x larger area than the Hubble eXtreme Deep Field (HXDF) full-depth area (ACS+WFC3/IR). The RXDF will cover the full Roman wavelength range with 7 bands, reaching AB = 30 mag in RZYJH, 29 mag in F, and 28 mag in K, over a full-depth area of 678.75 arcmin^2 embedded in a total area of 1,243 arcmin^2, and far exceeding the depths of the Roman Core Community Surveys (CCS). The RXDF is within the Euclid Ultra Deep Field (EUDF) near the North Ecliptic Pole (NEP), a strategic long-term field for generational space facilities, with a wealth of multi-wavelength data including extensive coverage from the James Webb Space Telescope (JWST) NEXUS Treasury program. The observations will cover 3 epochs at a 1-year cadence, each epoch divided into 3 sub-epochs ~10 days apart, enabling time-domain studies on time baselines from ~10 days to over ~2 years. The RXDF is uniquely positioned to address critical questions in reionization, large scale structure (LSS), growth of supermassive black holes (SMBHs), little red dots (LRDs), and high-z supernovae (SNe); the volumes probed by HST+JWST are too small at these extreme depths, and even the deepest CCS tiers are too shallow. In addition to our key objectives, a wealth of additional science will be enabled by engaging the community with our rapidly released datasets, revolutionizing a wide range of science for a lasting legacy. This short document, which is converted from the approved RXDF proposal, aims to provide the community with a summary of the program.
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All authors Haojing Yan, Anton M. Koekemoer, Yue Shen, Bangzheng Sun, Norman A. Grogin, Zihao Wu, Christian Kragh Jespersen, Rachel Somerville, Kyoung-Soo Lee, Dale D. Kocevski, Adam J. Burgasser, Pedro H. Bernardinelli, Yicheng Guo, Charles Steinhardt, Xiaohui Fan, Duncan Farrah, Gisella De Rosa, Feige Wang, Jinyi Yang, Lifan Wang, Fengwu Sun, Christopher N. A. Willmer, John David Silverman, Steven L. Finkelstein, Seth H. Cohen, Rolf A. Jansen, Rogier A. Windhorst, Brent M. Smith, Stefano Casertano, Anthony H. Gonzalez, Michael A. Strauss, Ray A. Lucas, Katherine E. Whitaker, Mingyang Zhuang, Rodrigo Angulo, Chloe Aurin, Micaela Bagley, Franz E. Bauer, Jessica M. Berkheimer, Rachel Bezanson, Alejandro S. Borlaff, Rebecca A. A. Bowler, Larry D. Bradley, W. N. Brandt, Denis Burgarella, Timothy Carleton, Delondrae D. Carter, Caitlin M. Casey, Christopher J. Conselice, Kyle W. Cook, Jeff Cooke, David A. Coulter, Tyler Desjardins, Tim Dewachter, Nicole E. Drakos, Simon P. Driver, Qiao Duan, Eiichi Egami, Andreas Faisst, Travis C. Fischer, Adriano Fontana, Ori Fox, Brenda Frye, Yoshinobu Fudamoto, Eric Gawiser, Mauro Giavalisco, Yuichi Harikane, Thomas Harvey, Nimish P. Hathi, Benne W. Holwerda, Taylor Hutchison, Olivier Ilbert, Akio K. Inoue, Lucy R. Ivey, Kartheik Iyer, Mathilde Jauzac, Ignas Juodzbalis, Jeyhan S. Kartaltepe, Daichi Kashino, Susan Kassin, Patrick Kelly, Kotaro Kohno, Stephanie LaMassa, Erini Lambrides, Rebecca Larson, Junyao Li, Zhiyuan Ma, Sangeeta Malhotra, Elizabeth McGrath, Peter Melchior, Marcio Melendez, Hironao Miyatake, Bahram Mobasher, Mireia Montes, Thomas Moore, Takahiro Morishita, Takashi Moriya, Leonidas Moustakas, Rohan Naidu, Rosalia O'Brien, Pascal A. Oesch, Masafusa Onoue, Rafael Ortiz III, Masami Ouchi, Robert G. Pascalau, Molly Peeples, Andreea O. Petric, Sara Petty, Justin Pierel, Marc Rafelski, Eniko Regos, Armin Rest, Mitchell Revalski, James Rhoads, Pierluigi Rinaldi, Aaron Robotham, Kate Rowlands, Pablo M. Sanchez-Alarcon, Paola Santini, Alice E. Shapley, Raymond C. Simons, Swara Ravindranath, Takahiro Sumi, Takumi S. Tanaka, Masayuki Tanaka, Scott Tompkins, Christina C. Williams, Edward J. Wollack, John F. Wu, L. Y. Aaron Yung

High Energy Physics (Experiment)

Search for Axion Dark Matter around \texorpdfstring{$15.6\,\mu\text{eV}$}{15.6 microeV} with a Broadly Tunable High-Temperature Superconducting Cavity

Jiwon Lee, Jinsu Kim, Ohjoon Kwon et al. (+9 more)

We report an axion dark matter search in the mass range of $15.30\text{--}15.85\,\mu\text{eV}$ using a broadly tunable high-temperature superconducting (HTS) haloscope. By soldering substrate-stripped rare-earth barium copper oxide (REBCO) films onto a copper shell, we achieved a quality factor 3–4 times higher than in copper cavities across its tuning band in an 8\text{-T} magnetic field. We set robust Frequentist 90%~confidence-level exclusion limits on the axion–photon coupling down to 1.3 times the KSVZ coupling, while a complementary Bayesian analysis achieves KSVZ-level sensitivity.
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All authors Jiwon Lee, Jinsu Kim, Ohjoon Kwon, Saebyeok Ahn, Seonjeong Oh, Sergey Uchaikin, Boris Ivanov, Arjan Ferdinand van Loo, Yasunobu Nakamura, Dojun Youm, SungWoo Youn, HyoungSoon Choi

Strongly Correlated Electrons

Successive Phase Transitions from a Composite Fermion Liquid to a Fractional Quantum Hall State at {\nu}=3/2 Driven by In-Plane Magnetic Field

Xinghao Wang, L. N. Pfeiffer, A. Gupta et al. (+3 more)

We report an even-denominator fractional quantum Hall state at {\nu} = 3/2 induced entirely by in-plane magnetic field B_|| in an ultra-high-mobility GaAs quantum well. As B_|| increases, the system undergoes two successive transitions: from a composite fermion liquid to a soft-gap FQH state (B_||~12.2 T), then via a topological phase transition to a hard-gap robust FQH state (B_||~14.7 T), accompanied by a daughter state at {\nu} = 19/13. We present systematic data, and discuss a possible scenario in interpreting these findings. Our work demonstrates that topological order may be engineered through k-space Fermi contour splitting under an in-plane magnetic field.
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All authors Xinghao Wang, L. N. Pfeiffer, A. Gupta, K. W. Baldwin, K. W. West, Rui-Rui Du

Quantum Physics

Quantum algorithm for PageRank computation through multistep quantum resonant transitions

Chuqing Wang, Hefeng Wang and Hua Xiang

We present a quantum algorithm for obtaining a quantum state that encodes the PageRank vector of the Google matrix through multistep quantum resonant transition (mQRT). In the algorithm, the PageRank vector is encoded in the ground state of a problem Hamiltonian associated with the Google matrix. By dividing the web graph corresponding to the Google matrix into a series of subgraphs with nested structure, we construct a sequence of Hamiltonians based on the subgraphs to form a Hamiltonian evolution path from a simple initial Hamiltonian to the problem Hamiltonian. The ground state of the problem Hamiltonian is obtained by going through ground states of the intermediate Hamiltonians via QRT step by step. This algorithm requires only one ancillary qubit, and the runtime of the algorithm is proportional to the number of steps. It provides a new way for efficiently obtaining the quantum state of the PageRank vector of large-scale networks.
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Mathematical Physics

Energy diffusion in a pinned harmonic chain with free boundary condition and interactions of increasing range

Yipeng Lu and Wei Wang

We consider a finite two-dimensional pinned harmonic chain with an interaction range that diverges with the system size and with conservative rotational noise. Under a joint scaling in which the interaction range diverges microscopically but vanishes macroscopically, we prove that the expected em- pirical energy measures converge to the unique measure-valued weak solution of the heat equation.
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Strongly Correlated Electrons

Observation of multipartite spin entanglement in a cuprate chain

S. F. R. TenHuisen, Z. Shen, V. Bhartiya et al. (+17 more)

Quantum materials are believed to host highly entangled states of matter, but probing and quantifying such entanglement has long remained experimentally elusive. Here, we use resonant inelastic X-ray scattering (RIXS) as a probe of multipartite spin entanglement. By projecting the RIXS cross section onto the appropriate spin excitation channel, we show that the Quantum Fisher Information can be extracted directly from the measured spin fluctuation spectrum. We detect at least 7-partite spin entanglement in the model one-dimensional cuprate Sr$_2$CuO$_3$, revealing one of the largest entanglement depths yet reported in a solid. The observed entanglement depth agrees with Hubbard-model expectations and persists to elevated temperatures. Our results establish RIXS as an experimental probe of many-body spin entanglement and provide a platform for extensions to charge and orbital sectors and nonequilibrium settings.
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All authors S. F. R. TenHuisen, Z. Shen, V. Bhartiya, V. Menon, P. Sharma, H. Padma, Z. Guan, W. He, M. K. Lajer, J. Li, D. Banerjee, J. Pelliciari, I. A. Zaliznyak, G. D. Gu, M. D. Lukin, S. Johnston, M. P. M. Dean, V. Bisogni, Y. Wang, M. Mitrano

General Relativity and Quantum Cosmology

Scalarized Einstein-Euler-Heisenberg black holes at the approach to extremality

Hong Guo, Xiao Yan Chew and Yun Soo Myung

We investigate extremal black holes with scalar hair in the generic Einstein-Euler-Heisenberg (EEH)-scalar theory with two scalar couplings to the Maxwell term. One is an exponential coupling with coupling constant $\alpha$ and the other is its polynomial coupling. We first construct scalarized black holes on the cold (C)-horizon of EEH black holes described by mass $M$ and magnetic charge $P$ both at the linear level, through the existence curves $\alpha_n(q)$ with $q=P/M$, and as fully backreaction solutions. As extremality ($q=q_e$) is approached, all existence curves accumulate, following $\alpha_n-\alpha_c\sim 1/\ln^2(q_e-q)$, at the critical branch $\alpha_c$ fixed by the Breitenlohner-Freedman bound for the near-horizon (AdS$_2\times S^2$) throat. We obtain scalarized extremal black hole (SEBH) with constant secondary hair and it is recovered exactly from the entropy function approach working on the near-horizon throat. Its entropy is an attractor invariant, being independent of the asymptotic modulus, so the scalar hair remains secondary. Exploiting this constant scalar, we seek further SEBHs with scalar hair keeping its charge $Q_s$ for the zero asymptotic scalar ($\phi_\infty=0$). In the $(q,\alpha)$ plane, we observe that these extremal solutions occupy $q\ge q_e$. Hence, the existence curves $\alpha_n(q)$ existing for $q\le q_e$ and the extremal branches bound the scalarized domain from opposite sides and they meet only at $q=q_e$.
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Mathematical Physics · Cross-listed from math.AG

Negative contacts in genus one: a comparison of punctured and root stack Gromov-Witten theories

Yu Wang

Let $D$ be a smooth divisor in a smooth projective complex variety $X$. For connected curves of arithmetic genus one with prescribed signed contact orders, we prove that the refined punctured cycle of Battistella–Nabijou–Ranganathan and the negative-contact cycle of Fan–Wu–You agree after pushforward to the common moduli space of stable maps with divisor evaluations. Thus the pushed-forward refined punctured cycle is the constant coefficient of the pushed-forward root-stack virtual class, normalized by one power of the root order for each negative contact. The key step is a comparison for the universal target. After restricting to finite-type open substacks determined by the fixed pair $(X,D)$ and numerical data $\Gamma$, we prove that the positive BNR space maps finitely and with generic degree one onto Crumplin's main component. Using Crumplin's genus-one component description and degree formulas, we identify this component's fundamental cycle with the constant coefficient of the universal orbifold virtual class under comparison of root orders. Refined zero-section pullback recovers the negative contacts, and compatible virtual pullbacks and root-forgetting pushforwards transfer the resulting identity to $(X,D)$.
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Strongly Correlated Electrons

Textures as a phase-transition probe for quantum spin chains

Heitor P. Casagrande, Isaac M. Carvalho, William J. Munro et al. (+1 more)

The idea of quantum texture has been recently proposed and used as a tool for quantifying coherences and for quantum gate identification. In this work we offer a study on its usage to quantum phase transitions, demonstrating the rugosity metric as a simple tool for effective phase-transition probing. We establish the link between rugosity in the computational basis and the hierarchy of spin correlators, and analyze rugosities defined in the global ground-state and in ground-states belonging to different magnetization sectors (to which we refer to as global vs symmetry-resolved rugosities) to study the phase diagram of the Heisenberg XXZ model. We find distinct rugosity signatures at both transition points. In particular, a sharp feature appears at $\Delta=1$ already for small systems, revealing a pronounced sensitivity of the correlation hierarchy encoded by the texture to this point. Since the BKT transition coincides with the isotropic $SU(2)$ point of the XXZ model, this behavior may reflect a particular sensitivity of rugosity to the structure of the spin-correlation hierarchy at isotropy.
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All authors Heitor P. Casagrande, Isaac M. Carvalho, William J. Munro, Krissia Zawadzki