Soft Condensed Matter
Physics-Guided Interpretable Machine Learning Framework for Anomalous Transport in Crowded Media with Tunable Flexibility
Zakiya Shireen and Sujin B. Babu
Transport in crowded media is governed by the interplay of multiple physical mechanisms. Quantitatively disentangling their individual and coupled contributions remains a longstanding challenge because the evolving microstructure continuously modifies their relative influence. Here, we develop a physics-guided interpretable machine-learning framework that couples Brownian Cluster Dynamics simulations with surrogate machine-learning models and SHAP-based interpretation to quantitatively disentangle the individual and coupled effects of total volume fraction, explorer fraction, and template bond flexibility on explorer-particle transport. We demonstrate the framework using binary colloidal systems in which explorer particles diffuse through a template network formed by irreversible bonds with tunable flexibility. Structural descriptors, mean-squared displacement, intermediate scattering functions, and displacement distributions reveal that network formation localizes explorer particles through enhanced transient caging. Bond flexibility emerges as an independent regulator of post-network relaxation by promoting local bond rearrangements that facilitate the release of transiently caged particles without altering the irreversible network
topology. Although crowding and composition dominate the overall transport response, quantitative attribution reveals how the relative contributions of crowding, composition, and template bond flexibility evolve as the confining environment develops. Beyond establishing bond flexibility as a distinct control parameter for relaxation in heterogeneous colloidal networks, this work provides a general physics-guided interpretable machine-learning framework for quantitatively disentangling coupled physical mechanisms in complex transport phenomena.
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Solar and Stellar Astrophysics
Solar Wind Proton Heating and its Effect on Temperature Anisotropy Evolution between 0.05 and 1 au
Etienne Berriot, Arnaud Zaslavsky, Olga Alexandrova et al. (+3 more)
This study focuses on the radial
evolution of the
solar wind
proton adiabatic invariants and temperature anisotropies in the inner heliosphere. More specifically, we study in-situ measurements provided by the Parker
Solar Probe, between 0.05 au and 0.25 au from the Sun, and
Solar Orbiter spacecraft between 0.3 au and 1 au. Throughout the studied range of radial distances, we observe a significant average heating in the direction perpendicular to the local
magnetic field for both fast and slow
solar wind populations. On the other hand, there is no clear deviation from adiabaticity in the parallel direction regardless of the wind speed. The perpendicular heating is enough to significantly reduce the generation of the temperature anisotropy expected from a double adiabatic
evolution. Despite the heating, an important portion of the
solar wind (especially the slower wind streams) develops substantial anisotropies with higher parallel temperatures, which eventually become constrained by kinetic firehose instabilities.
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All authors Etienne Berriot, Arnaud Zaslavsky, Olga Alexandrova, Pascal Démoulin, Petr Hellinger, Lorenzo Matteini
Quantum Physics
Optimal Quantum Eigenvalue Transformation via Linear Combinations of Hermitian Matrices
Yanqiao Wang, Yixuan Liang, Hongjia Chen et al. (+1 more)
We discover two complementary linear-combination-of-Hermitian-
matrices (LCHM) formulations to achieve a general non-normal
matrix eigenvalue transformation $g(A)$. Firstly, for $A=L+\mathrm{i} H$ with Hermitian $L$ and $H$, the vanilla LCHM formula represents $g(A)$ as a kernel integral of $g(\mathrm{i}(H+kL))$, and it contains linear-combination-of-
Hamiltonian-simulation (LCHS) [An, Liu, Lin, Phys. Rev. Lett. 2023] as the special case for
matrix exponentials. Secondly, for the angular Hermitian $X_\theta = \cos\theta L+\sin\theta H$, the Weyl LCHM formula expresses $g(A)$ via integrating $g(\mathrm{e}^{\mathrm{i}\theta} (X_\theta\pm\mathrm{i}(I-X_\theta^2)^{1/2}))$. For the
matrix power $g(A)=A^m$, the
Fourier projection of Weyl LCHM gives \[ A^m=\frac{2}{\pi}\int_0^\pi \text{e}^{\text{i} m\theta}T_m(X_\theta) \text{d}\theta = \frac{2}{N}\sum_{j=0}^{N-1} \text{e}^{\text{i} m\theta_j}T_m(X_{\theta_j}),\quad\theta_j=\frac{\pi j}{N},\quad \text{for every } N>m \] with Chebyshev
polynomial of Hermitian $T_m(X_\theta)$ and $N$ samples. The discrete formula is exact, introduces no truncation and angular quadrature error, and offers $\mathcal{O}(1)$ post-selection weights. LCHM formulas lead to new
quantum eigenvalue transformation (QET)
algorithms. For a degree-$d$
polynomial $p_d(A)$ on $|\psi\rangle$, our QET
algorithm can achieve optimal $\Theta(d)$
circuit depth and optimal $\mathcal{O}(||p_d||_{\infty}/||p_d(A)|\psi\rangle||)$ post-selection repetitions. LCHM-based QETs unify various
quantum linear algebraic problems with near-optimal $\mathcal{\widetilde O}(d\log(d/\epsilon))$ Clifford$+T$ gates, including driven ODEs (reduced to standard LCHS), iterative methods, resolvents, $\log(I+A)$, $(\lambda I+A)^\nu$, Sign and ReLU transforms, and Faber approximation on noncircular domains.
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All authors Yanqiao Wang, Yixuan Liang, Hongjia Chen, Jin-Peng Liu
Mesoscale and Nanoscale Physics
Strain-Programmable Interior Topological Channels
Jiawei Xia and Shuze Zhu
Topological channels are typically pinned to physical edges or heterogeneous interfaces. Physical edges expose the channels to localized disorder, whereas interface-based designs generally involve material or structural discontinuities. These constraints limit
geometric tunability and can compromise microscopic transport quality. Here we show that smooth strain can program topological channels within a single-component homogeneous
lattice through a mechanically constrained inverse-design framework. A strain-dependent Dirac mass provides a direct
geometric control principle: its zero contour defines the channel path, the contour-crossing topological mismatch fixes the net chirality, and the normal mass gradient sets the confinement width following an inverse-square-root scaling law. Unlike conventional pinned channels, these strain-engineered interior channels permit continuous control over channel geometry and confinement. We demonstrate the approach in a strained Haldane model, realizing straight channels at prescribed orientations, designed curved paths, and multichannel networks associated with higher-Chern-number phases. The resulting channels exhibit quantized transmission and spatial decoupling from boundary-localized disorder, establishing strain as a mechanical design field for programmable interior topological transport.
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Mathematical Physics · Cross-listed from math.SP
The Ultimate Ishii-Pastur Theorem for Whole-Line Ergodic Block Jacobi Operators
Zhenfu Wang, Bei Zhang and Qi Zhou
We establish an ultimate Ishii-Pastur
theorem for whole-line ergodic block Jacobi operators. We prove that, for almost every realization, the restriction of a maximal spectral measure to the region where the smallest nonnegative Lyapunov exponent is strictly positive is carried by a Borel set of zero capacity. In the scalar case, this settles the whole-line problem formulated by Damanik and Fillman \cite[Problem~4.7.18]{Damanik-Fillman-book}.
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Strongly Correlated Electrons
Kinetically induced order from mobility-constrained excitations
Aprem P. Joy and Urban F.P. Seifert
A fascinating feature of strongly correlated systems is that excitations may carry nontrivial
quantum numbers under emergent
symmetries which, in some cases, may strongly constrain their motion. We show that such constrained excitations can play a central role in driving
symmetry-breaking long-range order through a kinetic mechanism: coupling to a local order-parameter field activates the mobility of otherwise constrained excitations, and condensation of the order parameter then enables a large gain in kinetic energy, thereby stabilizing a phase with long-range order. We illustrate this mechanism in two settings: (i) a dimerization instability in a
spin chain with a magnetization dipole conservation law, and (ii) itinerant magnetism of electrons in the Kitaev-Kondo model, where charge carriers couple to local moments that form a
spin liquid. This mechanism becomes operative whenever a finite density of mobility-constrained excitations is present, either through non-
equilibrium preparation or thermal activation. In the latter case, we argue that increasing temperature can, counterintuitively, promote order by enhancing the kinetic-energy gain of thermally activated excitations.
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Quantum Physics
On some potentials based on exponential functions
Francisco M. Fernández
By means of a simple and systematic normalization method we show that some apparently different potentials based on exponential functions are equivalent. Present normalization method only requires that the potential exhibits a minimum and is finite when the radial variable tends to infinity.
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Materials Science
Integrating moment tensor potentials with finite-element modeling for heat transfer prediction in FLiBe-based molten salt systems
Mikhail Polovinkin, Ksenia Abramova, Oksana Rahmanova et al. (+8 more)
Molten fluoride salts are promising heat-transfer media for advanced molten salt reactors (MSRs), where reliable thermophysical property determination is critical for component design and safety. We present an integrated multiscale framework that couples machine-learning-driven atomistic simulations with finite-element (FE) modeling to predict the heat-transfer performance of FLiBe-based salts in a linear heat exchanger. At the atomistic scale, Moment Tensor Potentials (MTPs), actively trained on ab initio data, are developed for pure FLiBe (66-34 and 74-26 LiF-BeF2 mol%), FLiBe-LaF3, and FLiBe-UF4. These potentials are used in molecular dynamics simulations to obtain temperature- and composition-dependent transport properties (density, viscosity, thermal conductivity, and isobaric heat capacity), which are mapped as inputs to a three-dimensional FE model of the experimental thermal loop. The FE model with literature transport properties reproduces the experimental heat-transfer behavior of pure FLiBe to within 10% in the laminar regime and 18% in the transitional and turbulent regimes, validating the end-to-end pipeline for this composition. The same model with MTP-MD-derived transport properties systematically overestimates the heat-transfer coefficient by 25-28%, an offset consistent with the MTP-MD biases on thermal conductivity and viscosity. Applied to the ternary systems FLiBe-LaF3 and FLiBe-UF4 over 0-5 mol%, the MTP-MD-driven FE model predicts a mean reduction in heat-transfer efficiency of 8-11% relative to pure FLiBe, with UF4 exhibiting the strongest effect. The qualitative ordering of the three systems is the more robust result; the absolute value of the 8-11% figure is contingent on the MTP accuracy. The framework is complementary to high-temperature experiments and provides a physics-based pathway for the rapid screening of MSR coolant formulations.
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All authors Mikhail Polovinkin, Ksenia Abramova, Oksana Rahmanova, Farit Valiev, Andrey Isakov, Andrey Goryachikh, Alexander Galashev, Yurii Zaikov, Dmitrii Maksimov, Alexander Shapeev, Nikita Rybin
Astrophysics of Galaxies
Ly$\alpha$ Escape in JWST/NIRCam F430M-Selected H$\alpha$ Emitters at $z\simeq5.5$
Cheng Cheng, Zhen-Ya Zheng, Chunyan Jiang et al. (+8 more)
We study the Ly$\alpha$ escape fraction ($f_{\rm esc}$) in an H$\alpha$-selected sample of
star-forming
galaxies at $z\simeq5.5$, identified via JWST/NIRCam F430M excess and covered by archival VLT/MUSE data. By anchoring the intrinsic Ly$\alpha$ production to H$\alpha$ emission, our approach provides a direct and Ly$\alpha$-unbiased probe of the escape of Ly$\alpha$
photons in
galaxies with SFR $\gtrsim 0.1\,M_\odot\,{\rm yr^{-1}}$ at this epoch. Ly$\alpha$ emission is detected in 3 out of 12
galaxies covered by VLT/MUSE. Combining detections and upper limits, we place a conservative upper bound of $\langle f_{\rm esc}^{\rm Ly\alpha} \rangle < 0.32$ on the population-averaged Ly$\alpha$ escape fraction. We find that Ly$\alpha$ detections are preferentially associated with nearly
dust-free systems, while no clear correlation between SFR and $f_{\rm esc}$, suggesting a
stochastic picture of Ly$\alpha$ escape. Interestingly, three of the four Ly$\alpha$-detected
galaxies reside within a known overdense structure, suggesting that local environment may further facilitate Ly$\alpha$
photons escape. Our H$\alpha$-selected approach establishes a general and scalable framework for probing Ly$\alpha$ escape by combining JWST medium- or narrow-band imaging with ground-based spectroscopic data, enabling systematic and less biased studies of Ly$\alpha$ visibility in typical
star-forming
galaxies during the post-reionization era.
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All authors Cheng Cheng, Zhen-Ya Zheng, Chunyan Jiang, Fengwu Sun, Edo Ibar, Xin Wang, Haojing Yan, Fang-Ting Yuan, Jia-Sheng Huang, Juan Molina, Malte Brinch
Astrophysics of Galaxies
HI Depletion Begins Well Beyond the Virial Radius: A FAST Stacking Study of 36 Galaxy Clusters to 5R200
Cheng Cheng, Chuan-Peng Zhang, Edo Ibar et al. (+10 more)
We present a stacking study of the neutral atomic hydrogen (HI) content in and around 36 local
galaxy clusters at $z<0.07$, using a combination of the FAST all sky HI survey (FASHI) and the extensive spectroscopic catalog mainly from the Dark Energy Spectroscopic Instrument (DESI). We employ spectral stacking techniques to probe the average HI mass and HI-to-
stellar mass ratio ($M_{\rm HI}/M_*$) for member
galaxies down to
stellar masses of $M_*\sim 10^9M_\odot$, spanning a projected cluster-centric distance to $5R_{200}$. Our analysis reveals a pronounced environmental effect: both $M_{\rm HI}$ and $M_{\rm HI}/M_*$ decrease steadily towards the cluster center, dropping by $\sim 0.5$ dex on average from the outskirts to the core. Crucially, we find that $M_{\rm HI}/M_*$ of
galaxies remain lower than the field
galaxies even at the $5R_{200}$. This provides direct, statistical evidence for substantial gas stripping and pre-processing in the cluster outskirts, likely occurring in infalling groups and large-scale filaments. By further splitting the sample by $g-r$ color, we show that the HI deficiency persists at fixed
galaxy color: even the bluest cluster members exhibit $\sim 0.5$~dex lower $M_{\rm HI}/M_*$ than field
galaxies of similar color, reflecting environmental effects on the cold gas reservoir prior to full optical transformation. The total HI mass within clusters and their outskirts agrees broadly with predictions from cosmological simulation. Our results underscore the critical role of the extended cluster environment in quenching
galaxies by depleting their cold gas reservoirs well before they enter the dense cluster core.
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All authors Cheng Cheng, Chuan-Peng Zhang, Edo Ibar, Rory Smith, Weiwei Xu, Hyowon Kim, Jia-Sheng Huang, Wei Zhang, Pei Zuo, Hugo Méndez-Hernández, Juan Molina, Ming Zhu, Qian Yu
Solar and Stellar Astrophysics
High-Frequency Magnetohydrodynamic Waves with Substantial Energy in the Solar Polar Corona
Yuhang Gao, Hui Tian, Richard Morton et al. (+5 more)
The acceleration and heating of the fast
solar wind remain long-standing challenges in space physics. One type of leading theoretical models requires high-frequency magnetohydrodynamic (MHD) waves to transport and dissipate sufficient energy in the corona. However, such high-frequency waves with energetically significant amplitudes have never been unambiguously observed, leaving a key gap between theories and observations. Using high-cadence, high-resolution extreme-ultraviolet imaging from
Solar Orbiter's Extreme Ultraviolet Imager, we identify a previously hidden population of high-frequency MHD waves in coronal plumes of the
solar polar region. An analysis of the detected propagating kink waves shows that over one-third have periods shorter than 100 s, a population largely undetected by earlier instruments. Power spectral analysis demonstrates that these high-frequency waves carry substantial energy flux, which are significantly underestimated in lower-cadence data. These results suggest that high-frequency MHD waves may contribute importantly to the energy budget of the
solar polar corona and could play a role in
solar wind acceleration, highlighting the value of high-resolution observations for probing energy transport in magnetized space and astrophysical
plasmas.
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All authors Yuhang Gao, Hui Tian, Richard Morton, Tom Van Doorsselaere, Daye Lim, Mingzhe Guo, Jiansen He, Zhenyong Hou
Quantum Physics
Efficient Lindbladian Learning from Constant-Time Pauli Responses
Jiaxing Song, Yukun Zhang, Xiao Yuan et al. (+1 more)
Learning the generator of an open many-body system is more challenging than
Hamiltonian learning: local responses, which can directly reveal coherent interaction terms in closed-system dynamics, may also contain dissipative contributions in open-system dynamics. In this paper, we address this challenge by developing an efficient Lindbladian learning framework for a known local candidate generator dictionary with bounded dissipative support and either bounded dual-interaction-graph degree or bounded unweighted local strength. The framework resolves the coherent-dissipative ambiguity by treating local Pauli responses as a linear system over both types of generator terms. Inverting this response system separates their contributions and makes the individual Lindbladian coefficients accessible from local response data in a fixed short-time window. Within this framework, we develop two efficient learning
algorithms: Chebyshev–Lobatto response interpolation, which uses logarithmically many short
evolution times and has a post-mean cost linear in $M$, with the stated dependence on $\epsilon$, and Single-time projected response contraction, which uses a single fixed
evolution time and globally inverts a truncated response function. Both procedures estimate $M$ candidate coefficients to entrywise accuracy $\epsilon$ using $\widetilde{\mathcal{O}}(M/\epsilon^2)$ sample and classical post-processing complexity. Our theoretical results establish local response inversion as a scalable paradigm for learning, calibrating, and diagnosing complex
quantum systems from experimentally accessible short-time data.
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All authors Jiaxing Song, Yukun Zhang, Xiao Yuan, Yusen Wu
Earth and Planetary Astrophysics
Unmasking (44) Nysa: Evidence for a trilobate structure
Kate Minker, Anthony Berdeu, Gianluca Li Causi et al. (+16 more)
Context. (44) Nysa is one of the largest known E-type asteroids. Light curve inversion models have indicated that it may have an elongated shape commonly found in large binary systems. Aims. We aimed to identify the morphology and presence of possible satellites orbiting Nysa. Methods. We observed Nysa with the visible-wavelengths adaptive-optics instruments SHARK-VIS and SPHERE/ZIMPOL in order to image the object with the highest possible spatial resolution, and visually identified surface features on the object. A shape model was constructed from these images and photometric light curves using the ADAM code. Results. Imaging revealed a highly unusual morphology with multiple distinct surface features, including two distinct valleys most easily interpreted as colli. A faint satellite was identified in the deconvolution residuals in multiple
datasets. Conclusions. We determine that (44) Nysa is a binary system most likely consisting of a contact-trinary or highly-irregular, coherent primary object and a small satellite.
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All authors Kate Minker, Anthony Berdeu, Gianluca Li Causi, Josef Hanuš, Michaël Marsset, Al Conrad, Fernando Pedichini, Simone Antoniucci, Piero Vaccari, Nick Moskovitz, Benoit Carry, Tom Polakis, Marin Ferrais, Emmanuël Jehin, Roberto Bonamico, Rhiannon Hicks, Daejhanae Smith, M. Amine Miftah, Ester Marini
Atomic Physics
Near-deterministic loading of molecular arrays by microwave-assisted collisions
Etienne F. Walraven, Kang Feng, Jonas Rodewald et al. (+2 more)
Molecular tweezer arrays offer great prospects for
quantum simulation, sensing, and computing, and would benefit from methods that enhance loading efficiency. Whereas light-assisted collisions underpin enhanced loading methods for atomic tweezer arrays, this approach cannot be directly extended to molecular arrays due to collisional loss. We show how this collisional loss can be suppressed by shelving molecules in rotationally or vibrationally excited states, so that a shelved molecule interacts with a newly loaded molecule through a repulsive van der Waals interaction. By introducing microwave assisted collisions, we show how to control the final states and the energy released in a collision between a pair of molecules. Following this controlled collision, one of the two molecules can be ejected, and we explore several strategies for ensuring deterministic ejection. Our schemes rely on currently available techniques for
laser-coolable molecules, and we predict achievable filling fractions up to 96%, paving the way for scalable molecular arrays.
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All authors Etienne F. Walraven, Kang Feng, Jonas Rodewald, Michael R. Tarbutt, Tijs Karman
Statistical Mechanics
Fluctuation-dissipation violations in mean-field non-reciprocal spin glasses
Ot Garcés and Demian Levis
We study the out-of-
equilibrium dynamics of the spherical Sherrington-Kirkpatrick model with non-reciprocal asymmetric couplings. Rather than assuming stationarity, we derive the conditions under which the dynamical mean-field equations admit stable time-translational invariant solutions. We analytically solve the asymptotics of the correlation and response functions in the symmetric, uncorrelated and antisymmetric limits, showing that the fluctuation-dissipation
theorem is generically violated in the presence of non-reciprocity despite exponential relaxation, due to broken detailed balance rather than aging. Numerical results for generic asymmetry allow us to interpolate between these solvable limit cases, revealing faster dynamics as the asymmetry increases, together with oscillatory dynamics driven by antisymmetric couplings. These results provide a reference framework for understanding the dynamics of disordered, non-reciprocal systems, disentangling two distinct origins of fluctuation-dissipation violations.
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Statistical Mechanics
Macroscopic wall pressure and microscopic contact load in crowds without egress: social-group cohesion and boundary buffering
Bo-Shiun Shen and Son-Hsien Chen
Crowd safety in confined venues is usually evaluated through evacuation performance or pre-collision avoidance, while direct mechanical hazards in dense gatherings without egress remain poorly understood. We study an Elastic Reorientation Model (ERM), a Social Force Model (SFM), and their coupled dynamics. Post-collision behavior is represented by social-group cohesion ($\gamma_g$) and wall buffering ($\gamma_w$), while risk is quantified by the macroscopic wall line pressure ($P_{\text{wall}}$) and the microscopic maximum per-
agent collision impulse ($\delta p_{\text{max}}$). In the ERM, cohesion and wall buffering generally reduce $P_{\text{wall}}$ by retaining
agents in the bulk, but large groups exhibit a high-$\delta p_{\text{max}}$ hazard window at intermediate cohesion. As $\gamma_g\rightarrow1$, local pairing suppresses cluster growth and shifts kinetic energy from relative to center-of-mass motion, reducing $\delta p_{\text{max}}$. SFM pushing and sliding amplify $\delta p_{\text{max}}$, especially when
agent-
agent and
agent-wall interactions coexist, while active driving raises $P_{\text{wall}}$ through near-wall accumulation. The coupled dynamics produces a wall-pressure/contact-load ($P$-$p$) trade-off. Finite-size scaling reveals an independent-
agent-induced phase boundary at $\gamma_w=0.5$, characterized by a susceptibility discontinuity, and a grouped-
agent-induced continuous phase boundary along a finite segment of $(1-\gamma_w)(1-\gamma_g)=0.5$, characterized by divergent susceptibility and terminating at a critical point. Both disappear in the social-force-free ERM, showing that they emerge from the coupled ERM+SFM dynamics. These results provide mechanistic guidance for crowd-risk mitigation and safety planning in high-density venues without egress.
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Quantum Physics
Exponential de Finetti Theorems for Fermionic Gaussian States
Jędrzej Burkat, Michał Studziński and Sergii Strelchuk
We prove an exponential variant of the Gaussian de Finetti
theorem: the subsystems of permutation-invariant, free-fermionic Gaussian states are well approximated by convex combinations of almost-i.i.d. states that are Gaussian on subsets of their parts. Our result provides an error bound between the original state and its approximants that decays exponentially in the number of unconstrained parts, becoming super-exponential when the subsystem under consideration is small. The dependence of our bound on the local
Hilbert space dimension is polylogarithmic, giving an exponential improvement over the standard de Finetti
theorem of [Nat. Phys. 3, 645-649]. Previous works considered Gaussian-symmetric states, which are supported on the trivial irrep of the tensor matchgate representation. We extend these results to the broader class of Gaussian-invariant states, which contains, for example, i.i.d. copies of single-replica mixed Gaussian states. We show that Gaussian-invariant states are precisely the partial traces of Gaussian-symmetric states on locally enlarged replicas and always admit a purification into a larger Gaussian-symmetric state. As an application, we derive explicit convergence bounds for a hierarchy of convex relaxations of
polynomial optimisation over fermionic Gaussian states. For variational energy minimisation, the hierarchy gives lower bounds converging to the global Gaussian minimum. Combined with upper bounds from Gaussian trial states, these bounds quantify how far a variational calculation can be from the best energy attainable within the Gaussian family.
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Quantum Gases
Tunable state-dependent interactions in collisionally stable mixtures of polar molecules
Hubert J. Jóźwiak, Hanwei Yang, Eugen Dizer et al. (+2 more)
We propose encoding a pseudo-
spin-$1/2$ system in the ground ($v=0$) and first excited ($v=1$) vibrational states of polar molecules. Double microwave shielding simultaneously shields molecules in both states, suppressing two-body losses by orders of magnitude while strictly avoiding three-body recombination. The microwave dressing is state-dependent and results in highly tunable, long-range dipolar Ising exchange ($J_z$), density-density ($V$), and
spin-density ($W$) interactions. These interaction length scales readily exceed the typical interparticle spacing, pushing the molecules deep into the strongly interacting regime. In bulk gases, this enables the exploration of itinerant
quantum magnetism and
quantum droplets with novel anisotropic
spin textures; in optical
lattices, it naturally realizes extended Hubbard and $t$-$J_z$ models, opening new directions in
quantum simulation.
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All authors Hubert J. Jóźwiak, Hanwei Yang, Eugen Dizer, Arthur Christianen, Tijs Karman
Quantum Gases
Ro-vibrational van der Waals interaction between ultracold polar molecules
Kang Feng, Hanwei Yang, Hubert J. Jóźwiak et al. (+1 more)
We describe the ro-vibrational van der Waals interaction between ultracold polar molecules. This interaction is strong, leading to fast elastic collisions and orders of magnitude suppression of collisional loss. This enables evaporative cooling of
Fermi mixtures of molecules in different ro-vibrational states, without active shielding by applying external fields. The scheme is compatible with microwave shielding, where it enables controlled state dependent interactions, opening up new opportunities for
quantum simulation and
impurity physics. The interaction can also be used to stabilize fermionic molecules in optical
lattices, to control interactions in synthetic dimensions, for enhanced tweezer loading, and direct infrared shielding.
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All authors Kang Feng, Hanwei Yang, Hubert J. Jóźwiak, Tijs Karman
Soft Condensed Matter
Crack-Tip Opening as a Probe for Length-Scale Separation in Geometrically Nonlinear Solids
Raúl Lazo-Molina, Mokhtar Adda-Bedia, Mohit Pundir et al. (+2 more)
Soft elastic solids are highly deformable materials where fracture is driven by the complex coupling of
geometric and material nonlinearities. While
geometric nonlinearity (GNL) arises kinematically from the intrinsic capacity of solids to undergo large deformations, material nonlinearity stems from the constitutive behavior unique to each class of materials. Because GNL is a universal feature of all highly deformable solids, establishing its standalone impact is a prerequisite for understanding nonlinear fracture. Here, we focus on brittle soft solids to study the role of GNL alone on the near-tip fields of a static crack under mode I plane-strain conditions, providing a canonical baseline for integrating material nonlinearities in future investigations. By utilizing a compressible St. Venant-Kirchhoff material model, we analyze crack behavior under large deformations in the absence of material nonlinearity. We propose a robust postprocessing methodology based on the crack-tip opening displacement (CTOD) profile and derive asymptotic analytical solutions. Our results reveal a distinct near-tip region where the CTOD departs from classical linear elastic predictions, transitioning into a nonlinear regime dictated by Poisson's ratio. Using a matched-asymptotics approach, we define a physical nonlinear length scale $\lambda_\mathrm{nl}$ that bounds this region and scales quadratically with the far-field stress intensity factor $K_I$. We show that GNL acts as an intrinsic strain-stiffening mechanism sufficient to trigger energy partitioning, effectively shielding the crack tip and imparting an apparent toughening. Ultimately, we conclude that the geometrically nonlinear material model serves as a foundational framework for the broader study of nonlinear elastic fracture mechanics.
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All authors Raúl Lazo-Molina, Mokhtar Adda-Bedia, Mohit Pundir, Rodrigo Arias, David S. Kammer
Solar and Stellar Astrophysics
JWST/MIRI Detection of Molecular H$_2$ Winds from an Edge-on Class II Source HV Tau C
Vinod Chandra Pathak, P. Manoj, Himanshu Tyagi et al. (+14 more)
The
evolution of protoplanetary disks is regulated by
accretion onto the central
star and mass loss through jets and winds. While atomic and ionized
outflows are commonly observed, molecular winds in evolved Class II disks remain rarely detected. We characterize the spatial, thermal, kinematic, and dynamical properties of molecular hydrogen (H$_2$) emission from the nearly edge-on Class II disk HV Tau C and assess the impact of its molecular wind. We also constrain
accretion using H I recombination lines detected in the same mid-infrared spectrum. Using JWST/MIRI-MRS data from the MINDS Cycle 1 GTO program, we analyze spatially resolved pure-rotational H$_2$ emission. Rotational and position-velocity diagrams constrain excitation and kinematics, from which we estimate wind properties. We detect extended H$_2$ emission tracing a wide-angled, biconical molecular wind extending beyond the near-infrared scattered-light disk, ALMA 887 $\mu$m
dust continuum, and compact $^{12}$CO ($J=3$-$2$) gas disk. The H$_2$ rotational diagram requires warm ($\sim$600K) and hot ($\sim$2000K) components, similar to those in younger protostars. The gas shows outward motions of a few tens of km s$^{-1}$ and dynamical timescales of tens to hundreds of years. The inferred mass-loss rate is $\sim10^{-8}$ M$_\odot$ yr$^{-1}$, while
accretion rates derived from H I lines are $10^{-10}$-$10^{-8}$ M$_\odot$ yr$^{-1}$. The
accretion rate may be underestimated because of the edge-on geometry. Our results show that wide-angled molecular H$_2$ winds can persist into the Class II phase, with
outflow rates comparable to some protostellar systems, suggesting that such winds may remain important for angular momentum removal, disk
evolution, and dispersal. (Abstract modified; see the paper for the full version.)
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All authors Vinod Chandra Pathak, P. Manoj, Himanshu Tyagi, B. Shridharan, Th. Henning, I. Kamp, A. Caratti o Garatti, B. Banerjee, Mayank Narang, E. F. van Dishoeck, Kamber Schwarz, Manuel Güdel, Alice Somigliana, Giulia Perotti, Aditya M. Arabhavi, Sujay Vijay Jadhav, Göran Olofsson
Optics
Time-Reversal Invariant Topological Photonic Alloy
Feng Ruili, Qu Tiantao, Wu Xianbin et al. (+4 more)
Conventional approaches generate
quantum spin Hall (QSH) and
quantum valley
Hall (QVH) effects by breaking spatial inversion
symmetry across the entire photonic
crystal. Consequently, modulating the bulk transmission gaps within these periodic frameworks typically requires global modification of structural parameters throughout the
lattice, severely limiting device reconfigurability and post-fabrication adaptability. In this work, we demonstrate that global inversion
symmetry breaking is not a prerequisite for inducing topological phases. Instead, local and minimal
symmetry breaking is sufficient. Using a photonic
alloy platform based on random substitutional disorder in a parallel-plate waveguide, we show that a disorder-driven local breaking of z-direction mirror
symmetry and a local breaking of in-plane
symmetry are capable of opening topological gaps to trigger QSH and QVH phase transitions, respectively, thereby supporting robust helical edge states and valley kink states. Rigorous topological characterization via the reflection-phase winding method reveals a striking size-dependent scaling behavior in both configurations, where the threshold doping concentration required to trigger the topological phase transition asymptotically vanishes in the thermodynamic limit. By enabling flexible, on-demand bulk gap engineering simply through random doping tuning rather than global structural reconfigurations, this photonic
alloy platform not only deepens understanding of disorder induced topological physics but also offers a scalable, highly efficient design strategy for integrated topological optical communications.
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All authors Feng Ruili, Qu Tiantao, Wu Xianbin, Shi Xiaoxuan, He Mujun, Zhang Lei, Chen Jun
Applied Physics
Synergistic Role of Electron and Photon Dose in Stepwise Laser-Induced Complete Deoxygenation of Graphene Oxide Revealed by In-situ TEM
Israt Ali and Kenneth R. Beyerlein
Laser-induced reduction of
graphene oxide (GO) represents a highly promising route to
graphene synthesis, offering spatially localized processing, elimination of hazardous chemical reagents, and compatibility with ambient conditions. Here, we introduce a stepwise
laser reduction strategy employing a 532 nm pulsed
laser, monitored in real-time by in situ dynamic transmission electron microscopy (DTEM). By systematically varying the pulse sequence and the cumulative
photon and electron dose, complete deoxygenation of GO is achieved while preserving film integrity. Core-loss EELS confirms full removal of oxygen functional groups and restoration of the sp$^2$ graphitic network, evidenced by a ${\pi}^*-{\sigma}^*$ energy separation of 7.0 eV, in close agreement with graphite (7.1 eV). Crucially, the cumulative electron dose is identified as an active parameter governing the reduction mechanism: electron beam exposure accounts for approximately 5 at. % of the initial oxygen removal and synergistically lowers the energy barrier for subsequent
laser-driven deoxygenation, while excessive electron exposure compromises film integrity through crack formation. The optimal configuration achieves complete deoxygenation at a cumulative
photon dose of 2.5 x 10$^3$ mJ/cm$^2$ with superior in-plane crystallographic order and minimal beam-induced thinning. This work establishes a versatile multi-parameter strategy for controlled scalable
graphene synthesis via combined electron beam and
laser irradiation.
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Other Condensed Matter
Critical Ripples and Dirac Fermions in Crystalline Membranes
Sebastián Bahamondes, Rodrigo Soto-Garrido, Enrique Muñoz et al. (+1 more)
Crystalline membranes hosting Dirac
fermions, with
graphene as the paradigmatic example, combine two low-energy sectors with sharply different dynamics: nonrelativistic flexural
phonons and relativistic-like Dirac quasiparticles. We develop the low-energy field theory of this coupled system at charge neutrality and determine how this dynamical mismatch controls the coupling between the two sectors. In the long-wavelength flat phase, rotational
symmetry ties the renormalization of the leading local scalar strain–density coupling to the scale-dependent bending
rigidity, causing its dimensionless strength to decrease logarithmically. At the same time, flexural modes become parametrically slower than the Dirac
fermions, so the resulting fermionic feedback vanishes as a power law.The flat phase is therefore stable against this perturbation. The physics changes when elastic interactions or electronic softening destabilize the membrane at a finite wavelength, selecting a ripple pattern formed by modes at $\pm\mathbf{Q}$. For an isolated pair of ordering wavevectors, provided that commensurability-induced phase pinning is irrelevant, the transition is governed by the bosonic Wilson–Fisher fixed point, while the Dirac
fermions remain spectators. A genuinely hybrid electronic–structural critical point arises instead when
symmetry permits a mass-type Dirac bilinear to share the ripple's momentum and
quantum numbers, including horizontal-reflection parity. The transition is then described by the
chiral-XY Gross–Neveu–Yukawa universality class. Using the known one-loop critical exponents, we characterize this transition, determine the induced secondary elastic distortion, and show that the fermionic and bosonic velocities lock in the isotropic continuum limit.
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All authors Sebastián Bahamondes, Rodrigo Soto-Garrido, Enrique Muñoz, Vladimir Juričić
High Energy Astrophysical Phenomena
Pair luminosity and cooling of newborn strange star: Color-flavor-locked and two-flavor color superconducting quarks
Mikalai Prakapenia, Cheng-Jun Xia and Gregory Vereshchagin
Following the previous wor k[1] here we consider early thermal
evolution of hot strange
stars made of color superconducting
quarks in two different pairing states: two-
flavor color
superconductor (2SC) and color-
flavor-locked (CFL) phases, taking into account cooling by
neutrinos and electron-positron pair creation due to the Schwinger process. We show that Schwinger luminosity in the electrosphere is a universal function of temperature, independent of
quark matter phase for
quark chemical potential $\mu_q>280$ MeV. The surface of a strange
star in all the cases cools faster than its interior. This leads to a fast decrease of pair luminosity with time, so that it does not exceed $10^{46}$ erg/s at 1 second after strange
star formation.
Neutrino luminosity dominates over pair luminosity in all the cases except for the CFL phase with a large gap parameter $\Delta>60$ MeV, where there is a strong suppression of
neutrino emission. The total energy emitted in electron-positron pairs is always smaller than the energy emitted in
neutrinos, but they become comparable for the large gap parameter.
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High Energy Physics (Phenomenology)
A dispersive method to study CP asymmetries in hadronic multi-body $B$ decays
L. A. Heuser, A. Reyes-Torrecilla, C. Hanhart et al. (+5 more)
We present the details of a dispersive method to construct the amplitudes for hadronic multibody $B$ decays based on the universality of pairwise hadronic final-state interactions at low invariant masses. This approach allows us to split the amplitude into source terms controlled by phenomenological parameters and final-state interactions, governed by the precise knowledge of two-body dynamics, both resonant and non-resonant. As a concrete application, we make use of the well-determined low-energy pion-pion ($\pi\pi$) interactions to understand the enhanced localized CP violation observed in $B^{\pm}\rightarrow K^{\pm}\pi^+\pi^-$. Fitting only angle-integrated CP-asymmetry data, the method successfully predicts the Dalitz plot differential distribution of events and of the CP asymmetry in the low-energy region. This allows for a better understanding of the large localized CP asymmetry recently reported by LHCb, which is shown not to be driven by an absolute enhancement of CP-violating effects, but by a suppression of the CP-conserving part resulting from the interplay of several partial waves. Moreover, we show that the widely-neglected non-resonant isospin-2 contributions play an essential role in the description of CP violation in this system. The method can be straightforwardly adapted to other multibody decays, where final-state two-
hadron interactions drive the CP violation.
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All authors L. A. Heuser, A. Reyes-Torrecilla, C. Hanhart, Y. Huang, B. Kubis, P. C. Magalhães, T. Mannel, J. R. Peláez
Instrumentation and Methods for Astrophysics
The Lunar Farside Transients and Technology Telescope (LFT3) Mission
David R. DeBoer, Charlie K. Ashe, Owen A. Johnson et al. (+12 more)
We present here an overview of the Lunar Farside Transients and Technology
Telescope (LFT3) mission to take advantage of the extremely clear
radio frequency environment on the lunar farside.
Radio observations performed from the lunar farside effectively and fully mitigate two unavoidable limitations of terrestrial-based
radio telescopes: (i) the prevalence of interfering
radio transmitters from human activity; and (ii) the impact of the Earth's ionosphere. However, in the era of cost-effective access to the Moon, there are many scheduled lunar missions over the next few years, and the window of opportunity to perform
radio interference-free observations from the lunar farside is closing fast. LFT3 is the only mission proposed to go to the lunar farside and exploit this unique opportunity in human history. LFT3 will observe in an uncluttered
radio environment to conduct unambiguous technosignature searches, transient surveys,
solar physics and planetary emissions studies, spectral line observations, and cosmological science observations. LFT3 will provide an important incumbent use of the microwave spectrum for cislunar
radio astronomy.
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All authors David R. DeBoer, Charlie K. Ashe, Owen A. Johnson, Evan F. Keane, Andrew C. Lesh, Richard Lynch, Ella J. Marshall, Steve Prabu, Anže Slosar, Chenoa D. Tremblay, Jake D. Turner, Karl F. Warnick, Andrew P. V. Siemion, Jamie Drew, S. Pete Worden
Astrophysics of Galaxies
Chemical modelling of interstellar MgS
M. Rey-Montejo, I. Jimenez-Serra, T. Millar et al. (+8 more)
The detection of magnesium sulphide (MgS) and sodium sulphide (NaS) towards the
Galactic Center molecular cloud G+0.693 constitutes the first detection of metal sulphides in the interstellar medium (ISM). However, there is scarce information about the key reactions (either in the gas phase or on grains) involved in their formation. In this paper, we model the chemistry of MgS simulating the passage of a low-velocity shock to recover the abundances recently measured towards G+0.693. Through this chemical modelling, we analyse the dominant reactions involved in the formation and destruction of this molecule, their associated chemical time-scales, and the depletion factor needed to recover the observed abundances. We build the initial chemical network of MgS by using SiS as a proxy for this metal sulphide, and we investigate the exothermicity of these and additional, uniquely proposed reactions through
quantum chemical computations. We run a three-phase model (initial translucent cloud, cloud collapse phase and shock interaction stage) that mimics the
evolution and physical conditions of G+0.693. Our results show that a depletion factor of 1000 is required for elemental Mg to recover the observed abundances of MgS. This implies that potentially more than 99.9% of Mg is locked in
dust grains. The dominant reaction leading to the formation of MgS is the neutral-neutral reaction between MgH and S in the gas phase. This work represents the first analysis of the chemistry of the metal-sulphide MgS and suggests that Mg is largely incorporated into
dust grains, most likely in the form of silicates. However, additional laboratory and/or theoretical studies of the key MgS formation reactions are essential to obtain more reliable constraints. Future missions, such as PRIMA, will provide insights into the amount of metal-sulphides locked into interstellar
dust grains.
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All authors M. Rey-Montejo, I. Jimenez-Serra, T. Millar, R.C. Fortenberry, S. Viti, J. Garcia de la Concepcion, G. Vermarien, M. Sanz-Novo, L. Colzi, S. Zeng, V.M. Rivilla
Mesoscale and Nanoscale Physics
Abhijit Halder, Harsh Varshney, Snehamoyee Hazra et al. (+7 more)
Quantum oscillations offer a direct probe of
Fermi-surface
topology and electronic degeneracy, yet disentangling both simultaneously across the Lifshitz transitions of multiband systems has remained an open experimental challenge. Here, we use Shubnikov-de Haas spectroscopy on a high-mobility, dual-gated Bernal-stacked tetralayer
graphene (B-4LG) device to quantitatively reconstruct the complete sequence of six distinct
Fermi-surface
topologies-gully, annular, singly connected, and multiband pockets. The extracted oscillation frequencies determine the extremal momentum-space areas and their
spin, valley, and gully-resolved degeneracies, in quantitative agreement with our tight-binding calculations. We further show that a perpendicular
magnetic-field, combined with displacement-field lifts the valley degeneracy through an orbital-Zeeman coupling, producing a single-particle valley splitting of several $meV$, far larger than in
bilayer or trilayer
graphene. Our work demonstrates a framework for tracking
Fermi-surface
topologies and their
flavor degeneracies in multiband
quantum materials.
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All authors Abhijit Halder, Harsh Varshney, Snehamoyee Hazra, Santu Kumar Bera, Souvik Chakraborty, Ujjal Roy, Takashi Taniguchi, Kenji Watanabe, Amit Agarwal, Anindya Das
Instrumentation and Methods for Astrophysics
RAISE: A Low-Frequency Space-Based Payload for Solar Radio and RFI Measurements on the SMiLE Mission
Sangeetha A, Harsha Avinash Tanti, Abhirup Datta et al. (+2 more)
We present the
Radio-wave Apparatus for Investigating
Solar & Earth interference (RAISE), a compact low-frequency
radio payload proposed for hosting on the SMiLE mission. Operating from Low Earth Orbit, RAISE targets a spectral regime that is largely inaccessible from the ground due to ionospheric effects. The payload is designed to enable space-based observations of low-frequency
solar radio emissions while simultaneously characterizing terrestrial and ionospheric
radio frequency interference in the near-Earth environment. RAISE employs mode-dependent Earth-pointing and Sun-pointing observations to generate dynamic spectral measurements relevant to space weather studies and low-frequency
radio mission planning. As an experimental and technology demonstration payload, RAISE provides essential heritage for future space-based low-frequency
radio astronomy and space weather missions.
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All authors Sangeetha A, Harsha Avinash Tanti, Abhirup Datta, Anshu Kumari, Rajesh Bodade