High Energy Physics (Theory)
Holographic correlators with non-supersymmetric multi-particle states
Michele Giorgi and Stefano Giusto
We consider heavy-heavy-light-light (HHLL)
holographic correlators in which the heavy states are coherent superpositions of $n$-particle operators. In the limit of large $n$ and large central charge, $c$, with $n/c$ held fixed, these HHLL correlators are described by a classical supergravity computation. When the multi-particle operators are half-BPS, it has been shown that the $n/c\to 0$ limit of the HHLL correlator encodes the tree-level connected contribution to the 4-point function with the heavy operators replaced by two $n$-particle operators with finite $n$. We provide evidence that this relation continues to hold when the multi-particle operators are non-supersymmetric. Although our checks are carried out in the AdS$_3$/CFT$_2$ setting, we expect that our
conjecture extends to more general
holographic dualities.
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Mathematical Physics
Factorization method for a clamped obstacle from near-field measurements via a far-field transformation
General Ozochiawaeze and Isaac Harris
This paper considers an inverse shape problem for recovering an unknown impenetrable clamped obstacle in two dimensions from near-field point source and dipole measurements for the biharmonic Helmholtz equation in the frequency domain. The measured data consist of the scattered field and its normal derivative on a closed measurement curve surrounding the obstacle. Since the associated near-field operator does not directly admit the symmetric factorization required by the factorization method, we introduce a far-field transformation. This transformation is defined independently of the obstacle and augments the near-field operator into the associated far-field operator which does admit a symmetric factorization. This yields a rigorous complete characterization of the obstacle by the factorization method theory and leads to a practical reconstruction
algorithm based on the spectral data of the transformed operator. Numerical experiments are presented to demonstrate the effectiveness of the proposed method, with synthetic near-field data generated using the method of fundamental solutions. We also consider reconstructions using only scattered-field measurements generated by point sources, demonstrating the potential for reduced the amount of measured data.
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Optics
Path-Integrated Polarization Rotation Signatures in Subsea Networks: Cable Geometry Effects in 2023 Turkey Earthquakes
Mohammad M. Hosseini, Miquel Masanas, Giuseppe Parisi et al. (+5 more)
We analyze polarization data streamed from a commercial coherent transponder, used in MedNautilus link, during 2023 Turkey earthquakes. We show how earthquake features and cable geometry fundamentally govern the optical polarization response, taking the first steps for detailed interpretation in designing fiber-based seismic sensing systems.
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All authors Mohammad M. Hosseini, Miquel Masanas, Giuseppe Parisi, Wesley Braga Melo, Alberto Marullo, Danilo Decaroli, Sergei K. Turitsyn, Antonio Napoli
Strongly Correlated Electrons
Multiconfigurational Analysis of Local Electronic Structure of $\mathrm{RuO_2}$ Using Relativistic Embedded Clusters
Zhosan I. A., Lomachuk Yu. V., Maltsev D. A. et al. (+2 more)
We present a multiconfigurational, relativistic embedded-cluster study of the local electronic structure of ruthenium dioxide ($\mathrm{RuO_2}$), a candidate altermagnetic material. Starting from free $\mathrm{Ru}$ ions, we progressively build up the local environment through a $\mathrm{Ru+Q_6}$ electrostatic model, a bare $\mathrm{[RuO_6]^{8-}}$ ligand model, and finally a high-accuracy $\mathrm{RuO_6}$@CTEP embedded cluster that reproduces the crystalline surroundings. All systems are treated at the SA-CASSCF and NEVPT2+SOC levels of theory to capture strong electron correlation and
spin-orbit coupling on an equal footing. While the formal local site
symmetry of the $\mathrm{Ru}$ sites in $\mathrm{RuO_2}$ is orthorhombic ($D_{2h}$), we find that the calculated $4d$-orbital energy spectrum and its splitting pattern behave much closer to the higher tetragonal ($D_{4h}$)
symmetry, preserving a strong quasi-degeneracy among the relevant $4d$ orbitals. Since the local $xy$ quadrupolar order responsible for altermagnetic
spin splitting in independent-particle models relies on this
symmetry reduction, its suppression by orbital quasi-degeneracy offers a natural explanation for why altermagnetism is not observed in bulk $\mathrm{RuO_2}$ experiments, in contrast to the robust altermagnetic signatures reported in strained thin films.
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All authors Zhosan I. A., Lomachuk Yu. V., Maltsev D. A., Moiseev I. A., Andreev O. Yu
Statistical Mechanics
Formal Fluctuation-Response Relations for Non-Stationary Systems: The Dynamic Conjugate Variable
Igor M. Sokolov
Fluctuation-response relations (FRRs) connect the linear response of a system to an external perturbation with properties of spontaneous fluctuations in the unperturbed system. We provide a simple derivation of FRRs for non-stationary dynamics following an almost standard way based on introducing a variable conjugated to perturbation (a dynamic conjugate). The derivation relies solely on the Markovianity of the underlying dynamics, with the only additional assumption that the transition PDF of the process is differentiable with respect to the strength of a constant, time- independent perturbation. The structure of this conjugate variable is however unusual: it is a two-time one, and reduces to a usual single-time conjugate in stationary situations. We show how several known results follow from this approach.
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Quantum Physics
Noise-Robust Quantum State Characterization for Remote State Preparation with Deep Learning
Bo Tang, Zixuan Liao, Hao Li et al. (+9 more)
Quantum communication underpins secure information processing and scalable
quantum networks. In particular, remote state preparation (RSP) enables efficient
quantum state transfer, but accurately estimating target states under complex noise remains challenging. Here, we propose a
Transformer-based
Quantum State Characterizer (TQSC) model for noisy RSP experiments. Our model reconstructs experimentally prepared pure and mixed photonic polarization states from noisy measurements in complex scattering environments, while its
attention patterns provide physically grounded insights into correlations among the measured observables. The method achieves a mean
estimator-target fidelity exceeding 99.999% under complex scattering and dynamic Gaussian noise, while its robustness and generalization are further examined using Qiskit-simulated Bloch-ball states. Furthermore, in a practical MNIST image transmission task with held-out states, the decoded bit error rate is reduced from 50.34% to zero after TQSC post-processing. The TQSC model enables accurate tomographic characterization under dynamic noise and provides physically grounded post-hoc insights, holding promise for intelligent
quantum information processing applications.
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All authors Bo Tang, Zixuan Liao, Hao Li, Yilin Yang, Jiani Lei, Zengya Li, Jing Qiu, Zhaohui Dong, Zhengyang Mao, Yuanhua Li, Yuanlin Zheng, Xianfeng Chen
Chemical Physics
Truncated automatic sparse differentiation for machine learning interatomic potentials
Marcel F. Langer, Adrian Hill and Michele Ceriotti
Machine learning interatomic potentials (MLIPs) learn the mapping from atomic positions to potential energy. The forces, the negative gradient of this energy, drive molecular dynamics and are readily obtained using automatic differentiation. Higher-order derivatives, most notably the Hessian, describe collective motion and allow the direct prediction of experimental observables, but are considered computationally inaccessible for large systems. We suggest a solution: in physical systems, interactions decay with distance, and most MLIPs build on this locality through message passing up to a finite receptive field. This implies both sparsity of higher-order derivatives and their decay with distance. This structure can be exploited using automatic sparse differentiation (ASD). We explain how to compute the sparsity pattern for MLIP derivatives and demonstrate that, for multiple foundation MLIPs, ASD computes full Hessians of large porous materials exactly, but with modest speedups at best. The larger gains come from truncated ASD: discarding small, but nonzero, Hessian entries between distant atoms yields order-of-magnitude speedups with negligible impact on predicted observables.
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Astrophysics of Galaxies
Thioacetaldehyde (CH3CHS) on interstellar ices: a key molecule to unravel two chemical dichotomies in the ISM
María Mallo, Miguel Sanz-Novo, Marcelino Agúndez et al. (+6 more)
Thioacetaldehyde (CH3CHS), recently detected in TMC-1, has an abundance approximately 36 times lower than its oxygen analog, acetaldehyde (CH3CHO). This makes the CH3CHS/CH3CHO pair the one with the largest column density difference among the detected oxygen/sulfur analogue pairs in this cloud. We investigate the hydrogenation pathways of CH3CHS to address two chemical dichotomies in the ISM: (i) the differenciation between CH3CHS and CH3CHO, and (ii) the apparent absence of both CH3CHS in the G+0.693-0.027 molecular cloud and ethyl mercaptan (CH3CH2SH), in TMC-1. Our results reveal a complex scheme that involves multiple competing reactions, highlighting an efficient sequence of consecutive hydrogenations that can lead to CH3CH2SH. This finding suggests that the high S/O ratio observed for thioacetaldehyde in TMC-1 (~36), and even more pronounced in G+0.693-0.027 ($\geq$112), may result from its conversion via hydrogenation on the ice surface, contrary to the case of CH3CHO, which is more resistant to that chemical process. The straightforward hydrogenation of CH3CHS on ices, which can also take place even in the gas-phase at 150 K, provides a reliable explanation for its non-detection in G+0.693-0.027, where grain-surface chemistry is expected to play an important role, favoring the conversion of CH3CHS into CH3CH2SH, which is indeed detected in G+0.693-0.027. In contrast, TMC-1 represents a more pristine gas-phase environment, where grain-surface chemistry has a lower impact. Under these conditions, CH3CHS can persist, while CH3CH2SH remains undetected. Overall, our results show the entirely different reactivity that contributes to the chemical complexity of two of the largest interstellar sulfur factories.
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All authors María Mallo, Miguel Sanz-Novo, Marcelino Agúndez, José Cernicharo, Gisela Esplugues, Víctor M. Rivilla, Izaskun Jiménez-Serra, Carlos Cabezas, Germán Molpeceres
Chemical Physics
Collective Ion Dynamics from Finite-Volume Fluctuations in Model Explicit-Solvent Electrolytes
Jeongmin Kim
Understanding how collective ion transport emerges from
equilibrium fluctuations is central to electrolyte statistical mechanics. Finite-volume fluctuations provide an accessible route to this information, but their interpretation is complicated because they mix wave numbers and collective fields. Here, we extend the finite-volume counting framework for inferring collective ion
diffusion by combining the exact window projection with an inertial independent-particle reference, and apply it to a symmetric 1:1 solvent primitive model. The growth of ion-number fluctuations between the ballistic and plateau regimes appears nearly ideal, but this apparent ideality results from compensation between negative structural and positive dynamical excess contributions. The coupled ion-number–solvent relaxation further reveals a signed redistribution between solvent-associated and solvent-orthogonal projections that is largely hidden in the total response. The inferred collective
diffusion depends on observation length and dynamical closure: measured structure alone does not systematically improve the estimate, whereas the coupled-field description reduces the high-concentration discrepancy. These results provide a basis for analyzing more realistic electrolytes with mutually coupled ion-number, charge, and solvent fluctuations.
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Strongly Correlated Electrons
Unconstrained compact lattice QED$_{2+1}$ coupled to phonons: Gauss sectors, orthogonal semimetal, and deconfined criticality
João C. Inácio and Fakher F. Assaad
Gauge theoretic descriptions of 2D
quantum magnets are defined on a restricted physical
Hilbert space by imposing Gauss's law. In this work, we study an unconstrained compact
lattice QED$_{2+1}$ coupled to bond
phonons, in which local Gauss operators are conserved, but their
eigenvalues are not a priori fixed. Using exact auxiliary-field
quantum Monte Carlo simulations at $N_f = 2$, we investigate how the physical Gauss sector becomes energetically favourable, and how this process is connected to confinement and
symmetry breaking. We identify an orthogonal semimetallic (OSM) phase, in which
fermions striped off their gauge charge and form a Dirac
liquid. This phase mixes various Gauss sectors, and becomes unstable when Gauss's law is explicitly enforced. Upon the imposition of Gauss's law, compactness allows for monopole excitations carrying
antiferromagnetic (AFM) and valence-bond-solid (VBS)
quantum numbers. Gauge field fluctuations and spinon-
phonon coupling tune between the competition of such monopoles and generate a phase diagram with OSM, AFM and VBS orders. The transitions out of the OSM phase coincide with the dynamical generation of Gauss's law, while the competition between AFM and VBS charged monopoles produces a transition consistent with deconfined
quantum criticality. Thus our results establish that upon the projection to the physical
Hilbert space, deconfinement in compact
lattice QED$_{2+1}$ is always unstable towards either AFM or VBS order.
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High Energy Physics (Phenomenology)
Particle Physics Driven by Quantum Technology - Quantum Simulations and Quantum Sensing
Itay M. Bloch, Marcela Carena, Yifan Chen et al. (+3 more)
We review recent advances in particle physics enabled and motivated by the rapid progress of
quantum technologies. The continued development of
quantum computing toward large-scale, fault-tolerant systems has the potential to address dynamical problems that remain extremely challenging for classical computational approaches, opening new avenues for studying nonperturbative dynamical processes. Tabletop detectors and
quantum-enhanced technologies have reached unprecedented sensitivities, enabling novel searches for ultralight particles, gravitational waves, and other physics beyond the Standard Model in parameter regimes previously inaccessible to conventional instrumentation. Taken together, these developments highlight a rapidly evolving landscape in which
quantum technologies are beginning to reshape fundamental physics. We aim to synthesize recent progress and illuminate the opportunities they present for advancing particle physics in the coming years.
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All authors Itay M. Bloch, Marcela Carena, Yifan Chen, Xinran Li, Ying-Ying Li, Jing Shu
High Energy Physics (Theory)
Four-Point Yang-Mills Correlators in AdS$_4$ from All-Line Recursion: All-Plus, Single-Minus and MHV
Dhruv Pathak
We review Raju's all-line recursion relations for Yang-Mills theory in AdS${}_4$ and evaluate four-point correlators for the All-plus, Single-minus, and MHV helicity configurations. We point out the relevant deformation for the legs needed to obtain the correlators. In particular, we explicitly derive the expressions for all the residues contributing to all three correlators. We also perform an explicit numerical check with the results computed by Witten diagram computations and find perfect agreement with our results. Finally, we conclude by discussing some applications of these recursions for obtaining higher-point functions.
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Quantum Gases
Unified hydrodynamics for density and spin supersolids
Ashwath N. Madhusudan, Au-Chen Lee, P. B. Blakie et al. (+1 more)
Two-component supersolids can exhibit in-phase or out-of-phase component density modulations, corresponding to density and
spin supersolids, respectively. We formulate a general hydrodynamic theory for the collective dynamics of multicomponent supersolids, guided by their broken
symmetries and conservation laws. We
benchmark it against microscopic calculations for a binary dipolar condensate confined to an infinite tube, finding quantitative agreement for the sound speeds of all three Goldstone branches throughout the density- and
spin-supersolid regions. The resulting relations link collective-mode measurements to elastic coefficients and superfluid fractions.
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All authors Ashwath N. Madhusudan, Au-Chen Lee, P. B. Blakie, R. N. Bisset
Materials Science
Strain-Induced Metal-to-Insulator Transition in Antiferromagnetic SrCrO$_3$ Thin Films
S. Jöhr, A. Carta, J. Moreno et al. (+11 more)
Antiferromagnetic (AF) metals are rare, yet they combine properties attractive for spintronic devices like robustness against stray fields and electrical readout. Among AF metal
oxide candidates, SrCrO$_3$ remains largely unexplored due to its notoriously difficult synthesis. In this paper, we demonstrate the growth of high-quality SrCrO$_3$ thin films by magnetron sputtering on substrates that impose a wide range of tensile and compressive strains.
Muon spin relaxation experiments, supported by x-ray
magnetic dichroism, unveil the emergence of an AF phase with dilute
magnetic disorder at low temperatures, while resistivity measurements confirm the simultaneous metallic ground state of SrCrO$_3$ under low strain. As both compressive and tensile strain increase, a metal-to-
insulator transition is induced in the films, while the onset of the
magnetic transition temperature remains unchanged. Moreover, an intriguing resistivity upturn, accompanied by a change in the dominant charge-carrier type, occurs at a temperature that correlates with strain. These observations suggest a complex strain-dependent band structure, with strain-induced Jahn-Teller distortions or tilting of the CrO$_6$ octahedra that emerge depending on the sign of the strain, as inferred from density functional theory calculations.
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All authors S. Jöhr, A. Carta, J. Moreno, A. Suter, Z. Salman, A. Panda, J. Spring, G. De Luca, J. Herrero-Martin, B. Mundet, C. Piamonteze, M. Gabay, C. Ederer, M. Gibert
Computational Physics
Mechanical resilience of ultra-low-density racing-shoe foams
Jeremy A. McCulloch and Ellen Kuhl
High-performance racing shoes rely on ultra-low-density elastomeric foams that undergo large, repeated deformations during running. Yet little is known about how their mechanical properties vary throughout the shoe or change with repeated use. Here, we characterize the midsole foam in an elite-level racing shoe from the heel, midfoot, and toe of a new shoe and a shoe worn for 300 miles. Microscopy reveals a characteristic pore length scale of 128+/-18 um and supports an approximately isotropic continuum description. We then quantify the mechanical response under tension, compression, and shear. Remarkably, despite 300 miles of real-world use, the foam retains its mechanical response across all three loading modes and shoe regions. Energy return remains largely unchanged, with values of 85-93% in tension and compression and 64-71% in shear. At the same time, we observe strong regional variations, with tensile and compressive stiffnesses 38-51% lower in the toe than in the heel. The foam also exhibits a pronounced tension-compression asymmetry in Poisson's ratio. Together, these findings reveal a spatially structured and mode-dependent mechanical response that remains largely preserved after 300 miles of use. This mechanical resilience may extend the functional lifetime of racing shoes, with implications for runners, replacement recommendations, and sustainability.
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Materials Science
Tuning the Coercive Field in Ferroelectric Hf0.5Zr0.5O2-Al2O3 Heterostructures via Interfacial Charge Dynamics
Marshall B. Frye, Chanyoung Kim, Jeong-Woo Sun et al. (+8 more)
Interleaving dielectric layers into ferroelectric Hf0.5Zr0.5O2 (HZO) films increases the
memory window (MW) beyond what is accounted for by the dielectric constants. Determining the physical mechanisms behind these MW improvements is critical to reaching the full potential of HZO FeNAND. Here, we show that MW improvements stem from the interfacial charge dynamics enabled by oxygen vacancies at the interlayer interface. X-ray photoelectron spectroscopy(XPS) etching experiments demonstrate increased off-stoichiometry at the interface, with a 2.3x increase in oxygen vacancies. Polarization-dependent XPS and first-order reversal curves(FORC) show that tunneling between interfacial defect states causes a bidirectional internal bias of 0.56MV/cm. The impact of defects is further corroborated through phase-field modeling(PFM), which only recreates the coercive fields, FORC, and internal bias for defect densities and tunneling barrier heights that are consistent with experiment, quantitatively capturing an internal electric field of 0.55 MV/cm. The phase field models are then used to simulate 36 devices with varied charge densities and dielectric thickness to provide a predictive framework for further improvements in the MW of interlayer HZO. These findings redefine the role of defects in ferroelectric HZO from deleterious to engineerable and provide critical insights into how to tune ferroelectric device architectures for improved
memory.
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All authors Marshall B. Frye, Chanyoung Kim, Jeong-Woo Sun, John Wellington-Johnson, Lance Fernandes, Prasanna Venkatesan Ravindran, Bogdan Dryzhakov, TaeYoung Song, Mengkun Tian, Asif I. Khan, Lauren M. Garten
Earth and Planetary Astrophysics
Daytime seeing variations in Paranal through a SHABAR system. Description of the method and first measurements from the PoET solar telescope
A. M. Silva, B. Wehbe, A. Oliveira et al. (+8 more)
Aims. In this paper we present the software and first seeing measurements from a SHAdow Band Ranger (SHABAR) system that is coupled with the recently comissioned PoET
solar telescope, installed at ESO's VLT platform in the Paranal Observatory. The seeing measurements that are collected by this system play a pivotal role in the observational strategy of PoET, as it employs apertures ranging between 1 and 55 arcseconds to observe resolved
solar regions. As such, the usage of the smaller apertures hinges upon good observational conditions, which are assessed through real-time measurements from the instrument. Methods. We employ a SHABAR system, consisting of a series of scintillometers that are non-uniformly spaced in a bar, measuring the scintillation of the incoming light. The scintillation is measured in individual detectors, which are then used to characterize the atmospheric
turbulence at a given range of heights. We use previously derived formulations, following Kolmogorov
turbulence models, to model the collected data and transform it into a seeing measurement. Results. We find that the Paranal daytime seeing can reach values close to 1 arcsecond in the early morning, before the ground temperature increases and creates
turbulence in the lower layers of the atmosphere. Over the day, the seeing gradually worsens, with the median seeing reaching values larger than 4 arcseconds in the afternoon. We also find that these variations appears to be stable over the first weeks of observations, yielding compatible results when comparing 37 independent days of operations, with a median seeing of 2.37 arcseconds.
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All authors A. M. Silva, B. Wehbe, A. Oliveira, M. Abreu, C. Cardenas-Conde, A. Cabral, P. Moreno, J. H. C. Martins, M. A. Monteiro, N. C. Santos, R. Gafeira
Strongly Correlated Electrons
Collective Charge-\(2e\) Bosonic Excitations in Charge-Ordered Systems
Ping Tang
Charge order is conventionally characterized by a static modulation of the electronic density, while its collective excitations remain less developed from a quasiparticle perspective than those of
spin-ordered systems. Here, we formulate the collective excititations of charge order within an effective charge-pseudospin model, in which the charge-ordered ground state is represented by staggered pseudospin order. Quantizing fluctuations around this ordered state via a Holstein–Primakoff transformation, we reveal two branches of bosonic quasiparticles with degenerate, gapped dispersions that carry opposite quantized electric charges $\pm 2e$. We therefore term these charge-$2e$
bosons “bichargons,” closely paralleling the two
magnon branches of a bipartite antiferromagnet that carry opposite
spin angular momenta. We show that a temperature gradient drives the
diffusion of thermally excited bichargons, generating a charge Seebeck response when the degeneracy between the oppositely charged branches is lifted by tuning the chemical potential away from the charge-neutrality point. In contrast, despite carrying finite electric charges, a thermal bichargon gas remains electrically insulating under a static electric field because bichargon quasiparticle number is not conserved. An ac electric field, however, can parametrically generate coherent pairs of oppositely charged bichargons that support a finite dc drift current in the presence of a bias electric field, offering a bosonic analogue of photoconductivity mediated by photoexcited electron–hole pairs in
semiconductors. Our results establish bichargons as a new class of collective bosonic charge carriers in charge-ordered systems and extend the quasiparticle paradigm of
magnons in
spin-ordered systems to the charge sector, with electric charge replacing
spin angular momentum as the transported quantity.
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Mesoscale and Nanoscale Physics
Disorder-induced modulation of the nonlinear Hall effect in Weyl semimetals
Juan A. Cañas, Daniel A. Bonilla and A. Martín-Ruiz
We study the effects of
impurity scattering on the nonlinear
Hall response of Weyl semimetals within the semiclassical Boltzmann approach. We derive the rectified and second-harmonic conductivity tensors for a general momentum-dependent transport relaxation time and evaluate this quantity microscopically for short-range, Gaussian, screened Coulomb, and
magnetic impurities. For scalar disorder, the relaxation time is isotropic and chirality independent. The nonlinear
Hall response is then determined by the anomalous velocity associated with the Berry
curvature, and a finite net response requires energetically inequivalent Weyl nodes to avoid cancellation between opposite chiralities. Polarized
magnetic impurities lead to a qualitatively different behavior. We find that interference between the first- and second-order Born amplitudes generates a helicity-dependent anisotropic correction to the relaxation time. This anisotropy changes the tensor structure of the nonlinear
Hall conductivity and gives rise to a finite second-harmonic current for suitable orientations of the electric field relative to the
impurity polarization. For representative parameters, however, the anisotropic contribution is several orders of magnitude smaller than the dominant isotropic response. These results establish how the microscopic form of
impurity scattering enters the nonlinear
Hall response of Weyl semimetals through the transport relaxation time.
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Quantum Physics
Neutral atom quantum computing for materials science and quantum chemistry
J. D. Pritchard
Neutral atom arrays have emerged as versatile platforms for performing both digital and analogue
quantum computing and simulation, with demonstrations ranging from large-scale programmable
Hamiltonians realising topological phases or weighted graph optimisation to error-corrected logical
qubits with transverse gate operations. This paper provides a broad overview to the neutral atom platform, and the potential applications relevant to materials science and
quantum chemistry.
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Computational Physics
Correlation-Free Transition Path Sampling through Shooting Point Generation Guided by Committor Learning
Maximilian Negedly, Sebastian Falkner, Alessandro Coretti et al. (+1 more)
Studying the dynamical behavior of a system often depends on characterizing how it transitions between long-lived states. Because such transitions are rare, observing them usually requires specialized enhanced sampling techniques. Transition Path Sampling (TPS) is a well-established method for generating reactive trajectories, which is simple to implement and does not require the definition of a preconceived reaction coordinate. However, its efficiency is limited by its sequential nature and the resulting correlations between sampled paths. Previous work addressed this limitation by combining TPS with a sampling scheme based on conditioned Boltzmann Generators, a generative machine learning model capable of sampling a given target probability distribution. This approach produces uncorrelated transition paths but relies on an accurate reaction coordinate, which is rarely known in advance. Building on recent advances in committor learning, specifically on the Artificial Intelligence for Molecular Mechanism Discovery (AIMMD) method, in this work we introduce GenAIMMD, an iterative
algorithm that actively and self-consistently learns the ideal reaction coordinate (the committor) and trains a conditioned Boltzmann Generator to sample from arbitrary bias windows along it. GenAIMMD thereby provides a correlation-free and fully parallelizable path sampling scheme that does not require prior knowledge of the system's transition mechanism. We apply GenAIMMD to a two-dimensional toy model and a higher-dimensional
polymer system. In both cases, GenAIMMD succeeds in training the Boltzmann Generator and learning the committor.
Benchmark results show a substantial increase in performance compared to standard TPS.
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All authors Maximilian Negedly, Sebastian Falkner, Alessandro Coretti, Christoph Dellago
High Energy Physics (Theory)
The Page Transition in the Multi-Time Correlations of Hawking Radiation
Tushar Waghmare
The Page curve and the island formula describe a reorganization of
quantum information in Hawking radiation across the Page time. We study how this reorganization appears in correlations among emissions collected at several retarded times. The late radiation is treated as a covariant multi-time process, or process tensor, and $\chi_{\mathrm{island}}=\mathcal{N}_{\varnothing}-\mathcal{N}_{R}$ measures the temporal
memory removed when the early radiation register $R$ is supplied. Operationally, this quantity is the corresponding change in the optimal distinguishability of the radiation process from a Markovian reference. We exhibit evaporation processes whose single-bin states and all process marginals below a finite order $k_\ast\geq 3$ remain fixed and coincide with a CP-divisible reference, while $\chi_{\mathrm{island}}$ changes by order one at order $k_\ast$. The Page transition can therefore appear as a transition in the Markov order of the radiation process. When the interior mediates the late-time
memory,
entanglement-wedge reconstruction of the predictive interior from $R$ Markovianizes the late process; conversely, when the late process has a minimal predictive
memory and its future-affecting information is mediated by that
memory, Markovianization by $R$ supplies a simulator of its influence. A Hayden–Preskill evaporation comb and an evaporating-JT calculation realize this mechanism. The late radiation retains temporal
memory across the transition, while the early radiation becomes sufficient for predicting its future multi-time statistics.
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Nuclear Theory
A comprehensive theory framework for perturbative calculations of $\delta_C$ in superallowed beta decays
Chien-Yeah Seng
The present high precision determination of $|V_{ud}|$ from superallowed beta decays of $J^P=0^+$, $T=1$
nuclei is largely built on top of the “standard” calculation of the isospin breaking correction $\delta_C$ to the
Fermi matrix element, which assumes the splitting $\delta_C=\delta_{C1}+\delta_{C2}$, where $\delta_{C1}$ and $\delta_{C2}$ represent the “isospin mixing” correction and the “radial mismatch” correction, respectively. In this paper I show that this formalism violates the rule of nucleon basis independence, similar to the gauge invariance requirement in
quantum field theory, therefore its outcome is inevitably subject to uncontrolled systematic errors. I further argue that the perturbative formalism is the only approach that allows the computation of $\delta_C$ at the precision level required for the test of the Cabibbo unitarity. Advancing from existing literature, I develop the full “generating function approach” to compute $\delta_C$ perturbatively, with connections to
nuclear mass splittings and the isospin breaking in
nuclear charge radii as theory
benchmarks.
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Astrophysics of Galaxies
ELUCID. IX. Recovering the Substructures and History of the Coma Cluster
Xiong Luo, Huiyuan Wang, Weiguang Cui et al. (+7 more)
We employ constrained hydrodynamic simulations of the Coma
galaxy cluster from the ELUCID project to study its substructures and assembly history. Our simulations accurately reproduce the global properties of Coma, including its position, virial mass, radius, and surrounding large-scale filaments. Using a combined HBT+SKID method, we obtain a total intracluster light (ICL) fraction of $12.2\%-23.5\%$, consistent with recent observations. The mass-weighted ICL profiles of velocity dispersion,
stellar age, and iron abundance generally agree with MaNGA measurements, and its clumpy east-west elongation is closely linked to the merger history of the two brightest cluster
galaxies (BCGs). The simulation also successfully reproduces the north and west intracluster filaments (ICFs) detected by weak
lensing, and the surrounding
galaxy groups are distributed in
alignment with the directions toward the nearby A2199 and A1367 clusters. The simulation further predict a complex cluster assembly history, with two major mergers at $z=0.74$ and $0.45$, and a pericentric passage of the two BCGs occurring $\sim 0.64 \ {\rm Gyr}$ before its current state. Our results demonstrate that constrained simulations are a powerful tool for connecting observed structures to the unobservable assembly histories of individual
galaxy clusters.
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All authors Xiong Luo, Huiyuan Wang, Weiguang Cui, Yipeng Jing, Weipeng Lin, Neal Katz, Romeel Davé, Houjun Mo, Xiaohu Yang, Hao Li
Astrophysics of Galaxies
The Galactic centre G+0.633-0.0604 molecular cloud: A new astrochemical gold mine: II. Chemical richness
D. San Andrés, V. M. Rivilla, L. Colzi et al. (+4 more)
In recent years, the inventory of interstellar molecules has rapidly grown, yet detections of complex species are confined to a few chemically rich sources, raising the question of whether such complexity is genuinely rare or shaped by observational biases. We present the
Galactic Centre G+0.633-0.0604 molecular cloud, located in the southern part of the Sgr B2 complex, as a new and very promising laboratory for the discovery of new interstellar molecules. We analysed data from a high-sensitivity molecular line survey of G+0.633, covering nearly 100 GHz of aggregated bandwidth over the 31$-$275 GHz frequency range with the Yebes 40m, IRAM 30m and APEX
radio telescopes. G+0.633 exhibits an exceptionally rich molecular feedstock comparable to that of the chemically rich G+0.693 cloud in the northern part of Sgr B2, establishing it as its 'astrochemical twin'. We report new robust interstellar detections of 15 astrochemically relevant species, most of prebiotic interest, previously identified only in G+0.693 or a very limited number of sources. These species include urea, $C$- and $N$-cyanomethanimine, ethanolamine, glycolamide, carbonic acid, and dimethyl sulphide. Our results reveal that the extraordinary molecular complexity observed in G+0.693 is not unique, but may instead reflect a natural outcome of shock-dominated chemistry in the
Galactic Centre. The G+0.633 and G+0.693 clouds exhibit remarkably similar excitation conditions and comparable molecular abundances, establishing them as an ideal benchmarking pair for astrochemical studies. Moreover, G+0.633 offers a clear advantage for molecular observations over G+0.693 owing to the significantly narrower linewidths of its molecular line emission, nearly half as broad as those characteristic of G+0.693, making it an exceptionally powerful target for guiding the search for increasingly complex molecules in the ISM.
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All authors D. San Andrés, V. M. Rivilla, L. Colzi, M. Sanz-Novo, S. Martín, I. Jiménez-Serra, S. Zeng
Quantum Physics
VQE Validation on the Mononuclear T1 (Blue-Copper) Site: A Stepping Stone to the Multi-Copper Laccase Cluster
Lucia Malickova
Validating variational
quantum eigensolver (VQE) pipelines on realistic chemical systems is a critical stepping stone toward tackling classically intractable molecules. In this work, we report emulator-based validation of the VQE workflow proposed for the copper active site, executed on the LRZ Eviden Qaptiva emulator. A problem-tailored ADAPT-VQE with a full singles-doubles-triples (S+D+T) pool removes over 99% of the correlation error, reaching a stable plateau at 4.03 mEh relative to exact diagonalisation (148 selected operators). This establishes a >40x improvement over the hardware-efficient ansatz (HEA). Finally, we frame these emulator results as a robust baseline for upcoming physical
quantum hardware runs on Euro-Q-Exa.
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Strongly Correlated Electrons
Non-Thermal Effects in Fermionic Atoms Coupled to Open Cavities
Jules Sueiro and Marco Schiro
We study a
Fermi-Hubbard model coupled to a open dissipative single cavity mode. Using Keldysh diagrammatics we derive and solve the
quantum kinetic equations for the
fermions, taking the bosonic cavity mode as a source of non-
equilibrium noise and dissipation. In absence of Hubbard interactions we show that the
fermions reach generically a non-
equilibrium steady-state, characterized by a non-thermal distribution function. Quite interestingly we demonstrate that the latter exactly nullifies the heat-current between
fermions and cavity mode. We discuss the regimes of parameters where a low-frequency effective temperature description emerges and how the fluctuations affect the mean-field phase diagram for the superradiance phase transition. Finally we include Hubbard interaction in the weak-coupling regime and show that it leads to a crossover towards a full
equilibrium distribution.
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Statistical Mechanics
Khinchin's ergodicity and typicality in statistical mechanics
Dario Lucente, Marco Baldovin, Giacomo Gradenigo et al. (+1 more)
The formulation of statistical mechanics in terms of ensembles, originally proposed by Gibbs, has proved to be extremely effective in describing the
equilibrium state of many-particle systems, in the most diverse contexts (critical phenomena,
quantum mechanics, biophysics, just to mention a few). The reasons of this success are still debated, and the connection between dynamics and probability in large systems remains somehow elusive. Indeed, in order to derive the main results of
equilibrium statistical mechanics, strong assumptions on the ergodicity of the dynamics are usually required. Nonetheless, empirical observations seem to suggest that the predictions of the theory hold true even when such assumptions are not verified. In this paper we reconsider the point of view put forward by Khinchin, stating that the only relevant ingredients for the validity of statistical mechanics are the large number of degrees of freedom in the system and the choice of extensive observables, irrespectively of the details of the microscopic dynamics. In particular, the presence of dynamical chaos is not required. To this aim, we discuss some analytical and numerical results on a couple of classical integrable systems, the harmonic chain and the Toda model, showing that many important features predicted by
equilibrium statistical mechanics, as for instance Maxwell-Boltzmann distribution, are found even in absence of chaos.
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All authors Dario Lucente, Marco Baldovin, Giacomo Gradenigo, Angelo Vulpiani
Strongly Correlated Electrons
Emergent Surface Kondo Flat Band Driven by Competing Interactions in a Topological Ferromagnet
Nazar Zaremba, Susmita Changdar, Haojie Guo et al. (+28 more)
A central goal of modern condensed matter physics is to uncover new
quantum states of matter arising from the intertwined effects of strong electron correlations, magnetism, and band
topology. Heavy-
fermion phases, generated by Kondo interactions, represent one of the most remarkable manifestations of electronic correlations, and topological heavy-
fermion states have been identified in several non-
magnetic materials. Yet, the consequences of their competition with
magnetic order have remained largely unexplored. Here, we reveal a new phenomenon: the spontaneous spatial separation of correlated
quantum phases. By showing that magnetism can drive distinct strongly correlated electronic states to coexist in different regions of a single material, our work establishes a previously unknown mechanism for organizing
quantum matter and opens a new direction in the study of correlated topological systems. Using bulk-sensitive probes, we show that UAsS
crystals are, in the bulk, metallic ferromagnets with only moderate correlation-driven band renormalizations. First-principles calculations reveal a topological electronic structure hosting both nodal lines and Weyl points, pointing to a rich underlying
topology. Angle-resolved photoemission spectroscopy (ARPES) measurements are consistent with these predictions, resolving the nodal lines and Weyl crossings. In striking contrast, surface-sensitive ARPES and scanning tunneling microscopy/spectroscopy (STM/STS) measurements reveal a pronounced flat band pinned at the
Fermi level, accompanied by a sharp resonance – hallmarks of an emergent, strongly correlated Kondo state not captured by first-principles calculations.
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All authors Nazar Zaremba, Susmita Changdar, Haojie Guo, Iñigo Robredo, Daniel Lozano-Gomez, Andreas Leithe-Jasper, Rui Lou, Yurii Prots, Mitja Krnel, Markus König, Konstantin Semeniuk, Berit H. Goodge, Yuri Grin, Andrii Kuibarov, Oleksandr Suvorov, Alexander Fedorov, Adam Pikul, Ivan Soldatov, Rudolf Schäfer, Bernd Büchner, Oksana Kvitnitskaya, Yurii Naidyuk, Louis Lamm, Meike Pfeiffer, Elena Hassinger, Matthias Vojta, Sergey Borisenko, Miguel M. Ugeda, Jeroen van den Brink, Eteri Svanidze, Maia G. Vergniory
Quantum Physics · Cross-listed from math.PR
Parisi Formula for the ground state energy of quantum p-Spin Hamiltonians
Sohom Bhattacharya
Quantum $p$-local
spin glass
Hamiltonians are natural
quantum analogues of the classical
spin glass models. We provide an asymptotic characterization of the maximal energy achievable by the product states. We prove that for every $p \ge 2$, the limit of ground state energy exists and is given by a Parisi-type variational formula. This settles a question left open by Anschuetz et. al. (2025). The variational formula also recovers the known large-$p$ asymptotics as a consequence. Finally, we prove that the limiting product state energy is universal for a broad class of non-Gaussian interactions.
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