Peer Revenue Fully funded

Papers

Fresh from arXiv, typeset properly. Highlighted words trade on the market.

Physics

Watch Physics (sign in to use)

Thursday 23 July

High Energy Physics (Phenomenology)

Charged Higgs Search at Future Neutrino Telescope and Higgs Factory

We investigate the discovery potential of the charged Higgs boson at future lepton colliders and neutrino telescopes within two simplified benchmark scenarios with universal Yukawa couplings. We demonstrate that both the muon-track and cascade events at neutrino telescopes can be exploited to search for or constrain the charged Higgs boson through resonant neutrino scattering process, and we compare the sensitivities obtained under different astrophysical neutrino flux models. We study the effect of the detector volume of neutrino telescopes on the discovery potential of the charged Higgs boson. We study the signal of charged Higgs boson at future lepton colliders over different kinematic regimes using optimized reconstruction strategies. We compare the discovery potential of the two experimental approaches over the relevant parameter space and find that future lepton colliders generally provide better sensitivity in most of the parameter space, while neutrino telescopes with very large detector volume can offer competitive and complementary sensitivity in the heavy-mass region of the charged Higgs boson.
Read the full abstract

All authors YiCheng Dai, Wei Liao, Yi-Song Lu, Qi-Shu Yan

Physics and Society

Topological measures in weighted hypergraphs

Higher-order interactions introduce an additional structural dimension to complex networks, requiring consistent generalizations of classical topological measures. In hypergraphs, the definition of distance between nodes is not unique: beyond the conventional measure derived from clique projection, an alternative formulation that explicitly incorporates the sizes of hyperedges, those of their intersection and their weights has been recently proposed. Here, we generalize three distance-based topological measures, namely closeness centrality, betweenness centrality and node eccentricity, using this new hypergraph distance. Trough tractable illustrative examples, we demonstrate that the differences between results obtained with the two distances are systematic and arise from structurally meaningful features of the higher-order networks. Also, analyzing a series of real-world datasets, we show that hypergraphs can be divided into three distinct classes, corresponding to the possible dominance of specific orders of interaction over their general metric structure. This provides practical guidance on the possibility of limiting the analysis to only some specific interaction orders, reducing its complexity while maintaining the full information of the system.
Read the full abstract

All authors Ekaterina Vasilyeva, Liubov Tupikina, Daniil Musatov, Andrei M. Raigorodskii, Charo. I. del Genio, Stefano Boccaletti

Quantum Physics

Large deviations in quantum dynamics and complexity

We study three definitions of large deviation in many-body quantum dynamics: (i) via the full distribution of an extensive observable, (ii) via the distribution of measurement outcomes (from a continuous monitoring of the observable) over a time interval $t \le t_{\max}$, and (iii) via the distribution of expectation values over $t \le t_{\max}$. In generic systems without conservation laws, the large deviation function (i) reaches its longtime limit at $t \sim \mathcal{O}(1)$, independently of system size $N$. (ii) and (iii) reach their longtime limit at $t \sim e^{ N}$ and $t \sim \exp(e^{N})$, respectively. Before that, there is a sharp frontier between the explored and unexplored outcomes/expectation values; their distribution equals the longtime limit truncated at values that drift with $t_{\max}$. We propose that the evolution of these values with $t_{\max}$ provides a measure of quantum complexity.
Read the full abstract

Adaptation and Self-Organizing Systems

Enhanced robustness of evolving systems with bipartite topology

Evolving open systems, in which new entities are continually introduced and those turning unfit go extinct, exhibit a phase transition between a diverging phase, where the system size grows indefinitely, and a finite phase, where it remains bounded. We show that imposing a bipartite interaction topology alone leaves this transition unchanged when the two partitions are introduced with equal initial connectivity. In contrast, when the initial degrees are asymmetric, the robustness of the system is markedly enhanced such that the transition shifts to higher connectivity and the diverging phase persists even when both initial degrees individually exceed the critical point of the corresponding unstructured system. In addition, we find a re-entrant transition, i.e. a return to the diverging phase as asymmetry is increased while the initial degree of one of the partitions is fixed, making it lying entirely outside the original mean-field picture. An extended mean-field analysis identifies the origin of these effects such that in the asymmetric regime, a feedback between the bipartite handshaking constraint and different extinction rates drives the mean degree of emergent network far above the initially assigned connectivity. This degree elevation suppresses extinction probabilities across the community while simultaneously concentrating extinctions among recently introduced, low-degree nodes. The interplay of these two effects constitutes a simple and universal robustness mechanism for evolving systems with asymmetric bipartite structure.
Read the full abstract

Optics

Enhanced abrupt autofocusing and depth-of-focus of circular Airy derivative beams via controlled asymmetry

We demonstrate simultaneous enhancement of abrupt autofocusing and depth-of-focus (DOF) in circular Airy derivative beams through controlled asymmetry. The controlled asymmetry enables multiple discrete autofocusing events to merge into a single elongated focal region, thereby enhancing both the autofocusing ability and the DOF. The DOF is extended by up to 400% with a 32% improvement in autofocusing ability and a ~ 32 {\mu}m focal spot size, whereas the autofocusing ability can be further enhanced by up to 193% with a ~ 56 {\mu}m focal spot size, while maintaining nearly the same DOF. Experimental results show good agreement with numerical simulations. The resulting asymmetric circular Airy derivative beams (ACADBs), combining strong abrupt autofocusing with extreme DOF, offer promising applications in optical trapping, optical communications, microfabrication, and biomedical imaging
Read the full abstract

General Relativity and Quantum Cosmology

Using horizon shadows to distinguish a black hole and a white hole

Within theoretical frameworks such as loop quantum gravity, black holes may evolve into white holes through a quantum bounce. This paper uses general relativistic ray-tracing techniques to calculate the ray-traced imaging of accretion disks from the previous cosmic stage during the Kerr black hole and post-bounce Kerr white hole phases. Calculations show that the black hole image presents a crescent emission ring and a central shadow. In contrast, after radiation from the previous universe penetrates the rotating white hole, eccentric and asymmetric nested intensity ring structures form in the synthetic image due to frame-dragging and lensing effects. We analyze the influence of spin parameters, observation inclinations, and accretion disk geometric configurations on the distribution of this nested ring structure using synthetic images and intensity profiles. Building upon this, we introduce polarized ray-tracing calculations for radiation across evolutionary stages. This process results in the polarization image features after the polarization vector is subjected to the gravitational field and spacetime spin dragging during the photon propagation through the white hole horizon and internal spacetime. The spatial rotation patterns and concentric interference fringes in the white hole polarization images exhibit a distinct inter-ring polarization discontinuity. This phenomenon differs from the polarization behavior of black holes. The intensity ring structures and polarization inter-ring discontinuity features provide multi-band and polarimetric interferometry baselines to overcome morphological observational degeneracies. This provides theoretical guidance for future very-long-baseline interferometry (VLBI) to distinguish black holes and white holes.
Read the full abstract

Strongly Correlated Electrons

Gaplessness indicator by topologically trivial twisting operators

We propose several general necessary conditions for quantum many-body system in one dimension respecting U(1) symmetry to be gapped. We show that the ground-state expectation value of topologically trivial twisting operators must approach unity in the thermodynamic limit with a certain finite-size scaling. Equivalently, its violation can indicate gaplessness of U(1)-symmetric Hamiltonians. The topological triviality of such a twisting operator enables us to derive infinitely many other gaplessness indicators by static structure factor to any order in real experiments, which are impossible to obtain by earlier topologically nontrivial twisting operators. We also apply analytic and numerical calculations to test the efficiency and consistency of our results.
Read the full abstract

Quantum Physics

An Analytically Trained Variational Surrogate for Quantum Phase Estimation on NISQ Hardware

Quantum Phase Estimation (QPE) is a foundational algorithm for molecular ground-state energy estimation, but its deep circuit requirements make direct hardware execution impractical on Noisy Intermediate-Scale Quantum (NISQ) devices. We present an analytically grounded variational surrogate framework in which a shallow Variational Quantum Circuit (VQC) is trained to reproduce the QPE measurement distribution without any quantum circuit simulation. The training target is computed entirely classically via the Dirichlet kernel, evaluated directly from the Full Configuration Interaction (FCI) ground-state energy, the ancilla qubit count, and the time evolution parameter, eliminating the exponentially scaling simulation bottleneck of prior surrogate approaches. We apply this framework to the hydrogen molecule (H$_2$) with a symmetry-tapered Hamiltonian, conducting a four-stage experimental investigation on IBM Quantum hardware. Stage 1 compares linear and full entangler topologies for the $R_Y$-$R_Z$-$CZ$ ansatz, with and without XpXm Dynamical Decoupling (DD), across four distributional metrics (Hellinger distance, fidelity error, total variation distance, Jensen-Shannon divergence), identifying the linear entangler as optimal. Stage 2 varies VQC layers ($p=1$ to $5$) for the linear-entangler ansatz, identifying single-layer depth as optimal under hardware noise. Stage 3 applies this configuration to the reduced $R_Y$-$CZ$ ansatz, comparing ideal and noisy simulator-trained parameters. A supplementary noise analysis at $p \in \{8,64\}$ characterizes the depth-dependent interplay between circuit depth and DD effectiveness. The framework enables faithful QPE mimicry using a linearly scaling VQC, recovering the ground-state energy within the chemical accuracy threshold (1 kcal/mol), constituting a scalable, hardware-efficient paradigm for QPE-based molecular energy estimation on NISQ devices.
Read the full abstract

All authors Mousumi Kundu, Ashish Kumar Patra, Anurag K. S. V., Ruchika Bhat, Sai Shankar P., Alok Shukla, Jaiganesh G

Astrophysics of Galaxies

Observations of High Galactic Latitude Line and Continuum Emission (912 - 1600 Å) with New Horizons

We present observations of the cosmic ultraviolet background (CUVB) from 912 - 1600 A using the Stem aperture of the Alice spectrograph on the New Horizons spacecraft at 56 AU from the Sun, providing a spectral resolution of 9 A for diffuse sources. We detect emission lines of CIII (977 A) and CIV (1548/1551 A) at the 3 sigma level with strengths of 4200 +/- 1500 and 4100 +/- 1200 ph cm(-2) s(-1) sr(-1), respectively, and a marginal detection of OVI (1032/1038 A) at 1400 +/- 1300 ph cm(-2) s(-1) sr(-1). We report a 3 sigma detection of an emission line at 1135 A, which we have identified with the N I resonance triplet. Although this line had earlier been observed in FUSE and SPEAR data, it had been attributed to airglow or instrumental effects. We confirm, for the first time, that it must originate in the Galaxy. The dust-scattered continuum is dominated by a small number (N < 100) of O9 - B2 stars and shows the deep absorption feature near 1000 A seen in the stellar spectrum. Our models suggest an albedo of a < 0.5 over most of the spectrum (950 – 1550 A) for the dust grains with the phase function asymmetry of g < 0.6. We find an offset, comprising the extragalactic background light and halo contributors, consistent with our earlier results from the Box, including the decline in the offset near the Lyman limit. We confirm that much of the emission must be from an unidentified component of the CUVB.
Read the full abstract

All authors Jayant Murthy, James Overduin, Seth Redfield, J. Michael Shull, Joel Wm. Parker, Jon P. Pineau, Anne J. Verbiscer, Richard C. Henry

Quantum Physics

Generation of bright quantum high-order harmonic driven by combined coherent and bright squeezed vacuum light

Attosecond quantum light, formed by the superposition of high-order harmonics driven by intense quantum light, opens new routes to probe quantum-mechanical correlations in matter. In this study, we have investigated the macroscopic propagation effects of quantum high-order harmonics generated by the combination of strong coherent and weak bright squeezed vacuum (BSV) lasers interacting with atomic gas. Our results reveal that the pressure-dependent intensity of harmonics arising from absorbing or emitting BSV photons differs from that of harmonics generated using only strong coherent pulses. Macroscopic propagation simulations indicate that the action phase of harmonics is perturbed by the weak BSV pulses. This perturbation modulates the phase mismatch of sub-cycle attosecond bursts and affects their quantum properties when the gas pressure varies. The ability to generate bright quantum high-order harmonics lays a foundation for the establishment and application of attosecond quantum spectroscopy.
Read the full abstract

All authors Wentao Wang, Yaoshun Sun, Liyuan Wang, Lingrui Hu, Dajun Ding, Xiangyu Tang, Mingxuan Li, Jianmin Yuan, Sizuo Luo

High Energy Physics (Theory)

Boundary Completion of Vacuum Persistence Probability

The vacuum persistence probability, encoded in the imaginary part of the in-out effective action, is a basic measure of vacuum instability and particle production. However, its evaluation may appear prescription-dependent: the Bogoliubov prescription and the Green's function prescription can yield different results. This discrepancy reflects the incomplete treatment of the endpoint vacuum states in the conventional Green's function reconstruction of the effective action. We establish a boundary-completed reconstruction that consistently incorporates the bulk Green's function and the endpoint vacuum contributions, thereby determining the structure of the complete in-out effective action. The resulting vacuum persistence probability is uniquely determined and agrees with the Bogoliubov result.
Read the full abstract

2607.20936 · 23 Jul · v1: 6+10 pages. Comments are welcome. v2: 7+13 pages. Revised version with improved readability. The discussion has been expanded, and two illustrations of the boundary-completion mechanism have been added to the Supplemental Material. Accepted by Physical Review D

High Energy Physics (Theory)

Coherent states versus Glauber-Sudarshan States: Bootstrapping, Schwinger-Keldysh Contours and Lefschetz Thimbles

We investigate how, in a highly constrained system such as a four-dimensional diffeomorphism-invariant theory with vanishing bulk Hamiltonian and non-trivial interactions between the metric and additional degrees of freedom, transient excited states–called Glauber-Sudarshan states–can be constructed over supersymmetric minima. These states are generically non-supersymmetric and, although they are not minima of any potential, they admit positive-energy metric configurations that effectively mimic four-dimensional quasi-de Sitter backgrounds. We analyze how such states differ from conventional coherent states by studying their time evolution both in the canonical formalism–via boundary Hamiltonians–and in the in-in path-integral framework through Schwinger-Keldysh contours. We also examine the consistency of the construction across three complementary descriptions: the 1PI effective action, the Wilsonian (or exact renormalization group) effective action, and the Picard-Lefschetz (Lefschetz-thimble) decomposition of the Schwinger-Keldysh path integral, which provides the trans-series organization of the theory. In the presence of gauge-fixing and ghost sectors, we show that the dynamics of these transient configurations are governed by a nontrivial bootstrap relation that simultaneously constrains their behavior near supersymmetric Minkowski vacua and along quasi-de Sitter-like trajectories. Finally, we examine the Wheeler-DeWitt equation, the notion of time in the presence of transient excited states, and the emergence of the bulk Schrodinger equation. We further show that these states admit a natural structural interpretation analogous to the vertex operators that arise in the two-dimensional world-sheet formulation of string theory.
Read the full abstract

All authors Heliudson Bernardo, Tatsuya Daniel, Keshav Dasgupta, Brayden Hull, Yue Katherine Lei, Yiya Selina Li

High Energy Astrophysical Phenomena

Exploring Physics beyond the Standard Model from kHz-Gravitational-Wave Signals of Core-Collapse Supernovae

Recent advances in multidimensional modeling of core-collapse supernovae (CCSNe) have enabled detailed predictions of high-frequency gravitational-wave (GW) signals, offering a new probe of extreme matter and gravity. A proto-neutron star (PNS) emits quasi-continuous GWs through the excitation of its characteristic oscillation modes. State-of-the-art CCSN simulations show that these oscillations, in particular $g$- and $f$-modes, dominate the GW spectrum, with frequencies rising from a few hundred hertz to the kilohertz (kHz) range as the PNS compactness increases in the post-bounce phase. Therefore, the temporal evolution of these GW frequencies, if detected, would provide a direct and quantitative tracer of the PNS internal structure and the surrounding explosive dynamics. In addition to such standard GW emission mechanism, fully general relativistic (GR) simulations have revealed additional GW sources linked to more exotic physical processes. In highly massive progenitors, continuous mass accretion drives rapid PNS contraction and early black-hole (BH) formation, producing strong kHz GW emission that abruptly ceases when the PNS core is swallowed by the BH horizon. Similarly, a strong first-order quantum chromodynamics (QCD) phase transition can induce a secondary collapse and rebound of the nascent quark core, generating powerful, millisecond-duration GW bursts with frequencies exceeding $\sim$2 kHz. Alternative theories of gravity, such as scalar-tensor frameworks, predict spontaneous scalarization that can trigger multiple collapses of the PNS, yielding analogous high-frequency and broadband GW signals. The combined analysis of these GW signals, together with their detection by next-generation GW detectors, offers a promising multi-messenger pathway to identify smoking-gun signatures of new physics beyond the standard model of the CCSN GW mechanism and general relativity.
Read the full abstract

Atomic Physics

Measurement of the reduced dipole matrix element in Ba$^+$

We present a high-precision measurement of the reduced electric-dipole matrix element $\langle P_{1/2}\|r\|S_{1/2}\rangle$ in $^{138}\mathrm{Ba}^+$. By comparing off-resonant scattering rates with dispersive Stark-shift measurements, we determine the matrix element to be $3.322\,7(12)$, corresponding to a $P_{1/2}$ excited-state radiative lifetime of $7.866\,3(56)$~ns. Combining our experimental results with a prior model for the differential scalar polarizability $\Delta\alpha_0(\omega)$, we extract the static value $\Delta\alpha_0(0) = -73.09(12)$a.u. This determination directly improves the evaluation of the blackbody radiation (BBR) shift, minimizing a prominent systematic limitation in room-temperature $\mathrm{Ba}^+$ optical clock error budgets. These results provide a stringent benchmark for atomic-structure calculations and advance high-precision applications in quantum metrology and tests of fundamental physics.
Read the full abstract

All authors N. Jayjong, M. D. K. Lee, K. J. Arnold, M. D. Barrett

Quantum Physics

Random unitary circuits with constant spectral gap

We prove constant lower bounds for the spectral gap of the following random walks on unitary groups $\mathsf{SU}(2^n)$ on $n$ qubits. (i) Random Pauli Rotation: choose an $n$-qubit Pauli operator $P$ and an angle $\theta \in [0,2\pi)$, both uniformly at random, and apply $e^{\mathrm i \theta P}$. (ii) Brickwork Random Unitary Circuit: choose $n-1$ unitaries $U_{i}$ uniformly at random from $\mathsf{SU}(4)$ (including central phases of the parent group) independently, and apply $U_{2j-1}$ on two qubits $2j-1, 2j$ and then $U_{2j}$ on two qubits $2j, 2j+1$. Importantly, the gap bounds are independent of $n$ and apply for all finite dimensional unitary representations of $\mathsf{SU}(2^n)$ uniformly. Our results immediately imply that the Random Pauli Rotation and Brickwork Random Unitary Circuit converge to approximate unitary $t$-designs after $\mathcal{O}(nt)$ steps. As a consequence, we improve implications for the complexity growth of random unitary circuits as a function of the depth. The existing argument can be applied almost verbatim, but previously the depth had to be $\mathcal{O}(2^{cn})$ for some $c < 1$. Our unconditional constant spectral gap removes this restriction. We prove analogous constant-gap results for orthogonal and Clifford groups; the latter is indispensable for our result on the Brickwork Random Unitary Circuit. The former implies convergence to approximate orthogonal $t$-designs. In this case, the implied mixing time with respect to a constant additive and multiplicative error is optimal (up to an absolute constant factor) for $t=2$.
Read the full abstract

Nuclear Theory

Gauge Auxiliary-Field Quantum Monte Carlo Method for Many-Fermion Systems

We propose novel Quantum Monte Carlo (QMC) methods for interacting many-fermion systems by leveraging the stochastic gauge freedom, originally developed in Gaussian phase-space QMC, within the phaseless auxiliary-field QMC (AFQMC) framework. In particular, we reinterpret the conventional force bias in phaseless AFQMC as a drift gauge and explore Fermi gauges based on natural orbitals of a reduced one-body density matrix defined via a mixed estimator, yielding stochastic, time-dependent Hartree-Fock-like dynamics. We propose a symmetry-projection sampling scheme to enhance the sampling efficiency. As a proof of concept, we apply these gauge-augmented AFQMC methods to a simple shell-model Hamiltonian: the Lipkin-Meshkov-Glick model. Numerical results illustrate the potential of stochastic gauges to enhance accuracy and reduce fluctuations, underscoring the promise for advancing these new techniques toward more realistic shell-model applications.
Read the full abstract

Biological Physics · Cross-listed from q-bio.PE

Evolutionary Le Chatelier's Principle: Phenotypic Plasticity and Genetic Assimilation via Timescale Separation in the Price Equation

Phenotypic plasticity and genetic assimilation play key roles in adaptive evolution, yet their underlying mechanism has lacked a unified physical description. A major theoretical difficulty lies in the fundamental difference in timescales, as phenotypic plasticity occurs rapidly within a generation whereas genetic changes accumulate slowly across generations. Here, we formalize these processes by bridging the continuous-time Price equation, a foundational equation of evolutionary dynamics, with the physical concept of timescale separation. A sudden environmental change induces a fast plastic displacement of the phenotype relative to the slow genotypic variable. Through genotype–phenotype coupling, this displacement generates an internal genetic stress. We demonstrate that genetic assimilation is a dynamical relaxation process in which the genotype evolves to resolve this self-generated stress. These evolutionary dynamics mathematically realize Le Chatelier's principle, where the slow genetic response naturally amplifies the initial plastic shift in the same direction. The theory predicts that a weaker restoring force, which can manifest as larger clonal phenotypic fluctuations, requires a longer evolutionary timescale for assimilation. In the ideal limit of cost-free, perfectly adaptive plasticity, the relaxation time diverges, so assimilation effectively stalls. This formulation provides a macroscopic physical mechanism for genetic assimilation, offering a universal response law for evolutionary systems in which rapid phenotypic responses precede slower genetic change.
Read the full abstract

Materials Science

Uni-XAS: Alignment-Driven Bidirectional Multimodal Learning for X-ray Absorption Spectroscopy

X-ray absorption spectroscopy (XAS) is a key technique for probing local atomic environments, yet learning based modeling must bridge two heterogeneous modalities: 1D continuous spectra and 3D atomic structures. Existing approaches typically decouple forward spectrum prediction and inverse structure inference into separate regression tasks, hindering shared representation learning. Moreover, severe permutation ambiguity among identical atoms often limits inverse modeling to coarse structure descriptors rather than explicit 3D structure generation. In this work, we present Uni-XAS, a unified benchmark and learning framework that reframes bidirectional XAS modeling as a cross-modal alignment and conditional generation problem. We first propose XASLip, an alignment recipe coupling a physics-aware spectral encoder with an absorberaware manifold optimization strategy to resolve fine-grained intra-element coordination variations. Building upon this shared latent space, we formulate forward prediction as anchored absolute-spectrum generation via retrieval-augmented decoding, effectively preventing physical scale collapse and energy drift. For the inherently ill-posed inverse problem, we introduce Permutation-Rectified Flow Matching, which integrates type-wise optimal transport into a continuous generative flow to provide a principled solution to ligand permutation ambiguity without relying on heavy high-order equivariant architectures. Evaluated on a largescale standardized benchmark of 328,839 structure-spectrum pairs, Uni-XAS demonstrates strong performance in cross-modal retrieval, accurate absolute-spectrum prediction, and composition-conditional 3D structure generation, establishing a scalable, reproducible, and protocol-consistent foundation for multimodal learning and standardized evaluation in scientific spectroscopy.
Read the full abstract

All authors Suyang Zhong, Yuhao Zhao, Boying Huang, Fanjie Xu, Pengwei Xu, Haoyi Tao, Xi Fang, Jun Cheng, Fujie Tang

Quantum Physics

Multicritical dissipative phase transitions manipulated by dipole–dipole interactions

Precise control of criticality in superradiant phase transitions is essential for quantum state engineering and the simulation of nonequilibrium phase transitions. Here, we investigate theoretically multicritical phenomena in a dissipative two-Rydberg-atom cavity–QED system. The intrinisic dipole–dipole interaction between the two Rydberg atoms restructures the energy-level landscape of the atomic subsystem, thereby significantly modifying the boundary of the continuous second-order superradiant phase transition, and shifting both the phase boundary and the multicritical point toward weaker atom–cavity strengths. For sufficiently strong dipole–dipole interactions, the continuous second-order phase transition and the multicritical point both disappear, leaving only a discontinuous first–order phase transition that enables the emergence of a superradiant phase even at arbitrarily weak atom–cavity coupling. This work is of fundamental interest for studying dissipative quantum phase transitions, with potential implications for quantum precision measurement and quantum sensing.
Read the full abstract

All authors Jia-Xin Wang, Qian Bin, Jing-Jing Cao, Xin-You Lü

Materials Science

Visualizing Microwave-Driven Dynamics of Antiskyrmions and Surface Skyrmions

Microwaves provide coherent access to low-energy excitations and serve as effective probes of high-frequency spin dynamics in quantum and magnetic systems. For topological spin textures, microwave excitation is expected to generate rich collective responses, yet direct real-space observation of ultrafast dynamics remains limited. Here we use time-resolved Lorentz transmission electron microscopy to visualize microwave-driven dynamics in a hybrid antiskyrmion structure composed of a central antiskyrmion and surface skyrmions. We resolve the picosecond evolution of antiskyrmion area and second-harmonic signals, evidencing nonlinear responses of spin textures under microwave excitations. We track the core motions of the antiskyrmion and surface skyrmions, which follow distinct trajectories while sharing the same rotational sense. Micromagnetic simulations reproduce the key observations and associate the dynamic modes with the spatial modulation of the core profile along the thickness. These achievements establish ultrafast electron microscopy as a powerful real-space approach for probing high-frequency microwave-driven dynamics of topological magnetic solitons.
Read the full abstract

All authors Zhuolin Li, Daisuke Nakamura, Spencer Reisbick, Chuhang Liu, Myung-Geun Han, Kosuke Karube, Wataru Koshibae, Naoto Nagaosa, Yasujiro Taguchi, Yimei Zhu, Yoshinori Tokura, Xiuzhen Yu

High Energy Physics (Theory)

Quantum Mpemba effect in holography

We investigate the quantum Mpemba effect in a holographic superfluid, in which states with stronger initial symmetry breaking relax faster toward the symmetry-restored equilibrium. We demonstrate its emergence by identifying the shifted free energy computed from the energy flux into the black hole horizon as monotonic distance measure. By decomposing the nonlinear bulk dynamics based on quasinormal modes, we reveal that the anomalous relaxation is governed by a dynamical competition in which the slowest-decaying mode is suppressed while the second mode is amplified. These findings provide a holographic perspective on the quantum Mpemba effect in nonequilibrium relaxation involving strongly coupled degrees of freedom.
Read the full abstract

All authors Xian-Hui Ge, Shuta Ishigaki, Yu-Qi Lei, Yu Tian

Soft Condensed Matter

Cross-streamline diffusiophoretic migration of colloids in Taylor-dispersed channel flows

Diffusiophoretic transport of colloids in pressure-driven channel flow is commonly analysed in two limits: an early-time regime in which the solute field is fully two-dimensional, and a late-time macrotransport regime in which cross-sectional homogenization leaves only a weak axial bias on the particles. For colloids, however, many experiments operate in the broad intermediate window \(a^2/D_{\mathrm s}\ll t\ll a^2/D_{\mathrm p}\): the solute has entered the Taylor-dispersion regime, but the particles remain effectively non-diffusive across the gap. We show that the Taylor-dispersed solute retains a residual transverse gradient that is Péclet-enhanced relative to the axial gradient and decays only as \(t^{-1/2}\). This gradient is small in the solute concentration but large enough in \(\nabla\ln c\) to drive cross-streamline migration of colloids. Attractive fronts (\(c_{\mathrm f}>c_{\mathrm i}\)) move particles toward faster centreline streamlines, sharpening the leading edge and accelerating removal; repulsive fronts (\(c_{\mathrm f}<c_{\mathrm i}\)) move particles toward slower near-wall streamlines, broadening the trailing edge and delaying removal. Direct simulations and microfluidic experiments confirm these front-sharpening and front-broadening dynamics. An asymptotic Taylor-regime solute field, combined with a non-diffusive trajectory model, captures the observed front geometries, density profiles, and removal dynamics. The results show that Taylor-dispersed solute fields can remain dynamically two-dimensional for particles, even when their concentration is nearly cross-sectionally uniform.
Read the full abstract

Quantum Physics

Heralded high-dimensional module-based quantum computation

Parity measurements have been explored as building blocks for preparing and discriminating entangled states, as well as for implementing quantum computation. We first develop two alternative high-dimensional generalized parity modules, and then propose a procedure for constructing high-dimensional generalized module-based controlled-NOT gate. The construction of module-based quantum computing introduced here is deterministic, heralded, insensitive to the dimensionality of the computing basis, and postselection technique is not required. The result shows that out of $(d-1)!$ generalized parity modules, only modules $ \mathcal{P}=(j\ominus i)\bmod d$ and $ \mathcal{P}=(j \oplus i)\bmod d$ can be used as building blocks for high-dimensional quantum computing. Furthermore, we proposed an optical nondestructive scheme for implementing generalized parity module through quantum nondemolition measurements, and the success of the parity module is heralded by photon-number-resolving detectors and single-photon detectors.
Read the full abstract

Materials Science

Orbital Hall Effect Enables Field-Free Magnetization Reversal in Ferrimagnets without Additional Conversion Layer

The spin Hall effect provides a well-established route for electrical magnetization control, while the orbital Hall effect offers a powerful yet less explored source of angular momentum. Achieving field-free deterministic switching in straightforward orbital-torque architectures remains challenging. Here, we demonstrate orbital-Hall-current-driven switching in a Mo/CoGd bilayer without the need for a separate orbital-to-spin conversion layer across a wide temperature range. In this simplified geometry, Mo serves as both an orbital and spin current source. However, the spin contribution is insufficient due to weak spin-orbit coupling, which is consistent with first-principles calculations predicting a large orbital Hall conductivity. The adjacent ferrimagnetic CoGd layer provides both orbital-to-spin conversion and the perpendicular switching medium. Planar Hall and current-induced loop-shift measurements reveal a substantial unconventional z-polarized damping-like torque originating from interfacial symmetry breaking. Increasing the Mo thickness from 0.2 to 2 nm increases torque efficiency by approximately 31% (y-polarized) and 71% (z-polarized) components. This enhancement enables field-free deterministic switching with a critical current density down to 2.51 x 10^6 A cm^-2. Our results establish Mo/CoGd bilayers as a compact platform for orbital-current switching and point toward low-power orbitronic memory devices.
Read the full abstract

All authors Zelalem Abebe Bekele, Kun Lei, Xiukai Lan, Xiangyu Liu, Hui Wen, Weihao Li, Yongcheng Deng, Wenkai Zhu, Kaiming Cai, Lishu Zhang, Kaiyou Wang

Materials Science

Long- and Short-Range Anion Order in SrTiO$_{3-x}$H$_x$ Perovskite Oxyhydrides: DFT+$U$ Sensitivity and HSE06 Cluster Expansion

Anion ordering in perovskite oxyhydrides can remain significant even in disordered states, particularly at non-dilute hydrogen concentrations. Nevertheless, hydride substitution poses challenges for accurate simulations based on density functional theory due to configurational complexity and Ti 3$d$ reduction. Here, we develop a cluster expansion (CE) framework for SrTiO$_{3-x}$H$_x$ incorporating HSE06 hybrid-DFT energetics. We first demonstrate that calculated mixing energies and ordering stability are highly sensitive to the choice of DFT+$U$, with maximum variations on the order of 100 meV/anion. We benchmark ordering energetics against HSE06 calculations and identify $U$ = 3.3 eV as an HSE06 proxy, which enables extensive configurational exploration while limiting costly HSE06 calculations to key configurations for efficient learning of ordering energetics. Together, ground-state orderings, correlations between octahedral configurations and structural stability, and MC sampling of CE models all support a strong preference for the O$_4$H$_2$ cis configuration in SrTiO$_{3-x}$H$_x$, in which two hydride ions occupy first-nearest-neighbor anion sites. This cis-type preference was overlooked in previous ATiO$_{3-x}$H$_x$ studies, despite its sizable stabilization of ~200 meV per hydride comparable to reported anion-migration and polaron-formation energies. This study addresses both the previously underexplored sensitivity of CE-based ordering analyses to DFT+$U$ and anion-ordering in perovskite oxyhydrides.
Read the full abstract

Cosmology and Nongalactic Astrophysics

A lower bound on primordial power spectrum from halo substructure

We investigate how the primordial curvature perturbation of a certain wavelength scale affects the halo and subhalo structure. Primordial power spectrum considered in this paper features a nearly scale-invariant form with a cutoff at the wavenumber $ k = \mathcal{O}(1)~$Mpc$^{-1}$ and an additional log-normal bump at smaller scales. We compute the host halo evolution, as well as the subhalo mass function. To be consistent with the observations of stellar streams and gravitational lensing data, the amplitude of the bump that is typically the same or larger than $10^{-9}$ of the primordial curvature perturbation should be present at the wavenumbers of $10$ - $30$ Mpc$^{-1}$.
Read the full abstract

All authors Shin'ichiro Ando, Nagisa Hiroshima, Koji Ishiwata, Tomo Takahashi

Materials Science

MatDiffract: A Material-Informed Automated Analysis Platform for X-ray Powder Diffraction

High-throughput experimentation and self-driving laboratories are drastically accelerating materials discovery, yet automated interpretation of X-ray powder diffraction (XRPD) data remains a critical rate-limiting step. Conventional search-match workflows rely heavily on expert manual intervention, while pure data-driven machine learning approaches suffer from limited generalizability across chemical systems and lack rigorous crystallographic interpretability. Here we present MatDiffract, a material-informed automated analysis platform for high-throughput XRPD characterization. Built on a first-principles density functional theory (DFT)-derived inorganic crystal structure database, Atomly, MatDiffract constructs a perturbation-augmented simulated diffraction database, embeds multi-scale diffraction features into indexable vectors, and integrates hierarchical vector retrieval with full-pattern fitting Rietveld refinement and quantitative phase fitting. Benchmarked on 875 single-phase experimental patterns, the platform achieves 91.3% Top-1 and 97.2% Top-10 identification accuracy after automated refinement. For binary and ternary multiphase mixtures, it delivers 85.0% and 70.0% Top-1 accuracy with mass fraction mean absolute errors as low as 1.2% and 1.8%, respectively. Beyond mere phase labeling, MatDiffract outputs full crystallographic results including refined structural models, fitted profiles, and quantitative compositions within tens of seconds per sample. Its modular vector-based architecture supports seamless incremental expansion to new material systems, providing an end-to-end solution to close the characterization throughput gap for autonomous materials discovery and high-throughput materials development.
Read the full abstract

All authors Hongqing Wang, Mingwei Chen, Hongjie Luo, Wen Yin, Fazhi Qi, Xuqing Chai, Miao Liu, Fengyao Hou

Physics and Society

Invisible walls: how pedestrians navigate around social interactions

Pedestrian dynamics are characterized as complex physical systems constrained by social norms, like personal space. Yet, prior research has ignored the spatial norms imposed by others' social interactions, such as conversations. Unlike physical obstacles, the boundaries of social interactions are latent — even more so than those of personal space — as if they are invisible walls, and must be inferred from signs of interactional involvement. In four field experiments with 4,911 participants, we show that pedestrians integrate others' gaze, proximity, body orientation, and talk to avoid interrupting possible interactions. However, pedestrians also collectively violate these spatial norms by walking through an interaction if other pedestrians had already done so. These results demonstrate how physical mobility depends on pedestrians' social computations.
Read the full abstract

All authors Jack Terwilliger, Julia Di Silvestri, Seika Murase, Anne Elizabeth Clark White, Federico Rossano

Mesoscale and Nanoscale Physics

Machine Learning for Charge State Characterization of Isolated Double Quantum Dots

Scaling semiconductor quantum dot arrays toward fault-tolerant quantum computing requires efficient tuneup of spin qubits, a process that depends on the analysis of charge stability maps (CSMs) and remains largely manual. While machine learning has been widely applied to CSM analysis in reservoir-coupled devices, automated tuning in the increasingly important isolated-mode regime has received limited attention. In isolated-mode CSMs, charge transitions appear as near-vertical lines, making them well suited to compact, task-specific models. We present two convolutional neural networks with fewer than one million parameters, trained on CSMs collected from 32 silicon metal-oxide-semiconductor (SiMOS) double-quantum-dot devices measured at approximately 1 K using an automated cryogenic probing system. Sixteen devices were used for training and sixteen were held out to evaluate cross-device generalization against hand-labeled ground truth. CSMClassifier identifies charge instability and sensor artifacts, achieving 94% macro-averaged accuracy across three quality classes on 2,407 held-out images. ChargeLineNet localizes charge-transition lines and determines electron occupancy, achieving 95.3% exact line-count accuracy on 1,131 held-out images. Combined into a single pipeline, the models correctly determine electron occupancy for 93.8% of clean held-out images. Pre-training on synthetic images substantially improves label efficiency. Fine-tuning the pre-trained model on limited experimental data maintains over 90% accuracy, whereas training from scratch degrades significantly under the same conditions. Together, the two models occupy only 6.5 MB and process images in less than 60 ms on standard laboratory hardware, demonstrating a practical path toward scalable, automated characterization and tuneup of quantum-dot devices.
Read the full abstract

All authors Hyma Vallabhapurapu, Marco Candido, Krishna Choudhary, Paul Steinacker, Ensar Vahapoglu, Chris Escott, Wee Han Lim, Andre Saraiva, Nard Dumoulin Stuyck, MengKe Feng

General Relativity and Quantum Cosmology

Graviton-induced which-path decoherence in matter-wave interferometry

We derive which-path decoherence for matter-wave interferometry that arises from tracing out the gravitons of linearized quantum gravity. Because the gravitons are driven linearly by the matter source, the branch-dependent evolution can be solved exactly, and the reduced coherence is given by the characteristic function of the initial graviton state, evaluated at the difference of the branch-induced field displacements. In vacuum, the decoherence exponent equals half the mean number of gravitons radiated by the difference source. For a smooth Gaussian trajectory, it reduces to $\Gamma_{\rm vac}=(8/15)\,Gm^2d^4/(\hbar c^5\tau^4)$, ranging from $10^{-89}$ to $10^{-61}$ across representative matter-wave platforms. For a general squeezed graviton vacuum, we obtain an exact expression in which squeezing either suppresses or enhances the vacuum response, depending on the squeezing phase. For the strongly squeezed state produced by inflation, this expression reduces to $\Gamma_{\rm inf}=(\pi/20)\,\Omega_{\rm inf}(md^2H_0/\hbar)^2$ and reaches at most $\sim10^{-27}$ for optimistic parameters. Hence, the which-path decoherence induced by radiative gravitons is therefore negligible in current matter-wave interferometers.
Read the full abstract