High Energy Physics (Phenomenology)
Strong Constraints on Higgsino Dark Matter from Solar Capture
Maxim Pospelov and Harikrishnan Ramani
Higgsino dark matter remains one of the most convincing dark matter candidates. It can exist in a “quasi-Dirac" regime, when the splitting between two Majorana components is on the order of $O(\rm few~\,MeV)$ or less. Owing to the strong gravitational pull of the Sun, the DM particles accelerate to up to $\sim 1400$\,km/sec in the
solar core, which allows for inelastic scattering on heavy elements and very effective capture onto
solar-bound trajectories. We evaluate the expected flux of the
neutrinos from the expected $\chi\chi \to W^+W^-,ZZ$ annihilation for the cosmologically preferred mass, $m_\chi \simeq 1.08$\,TeV while keeping the mass splitting $\delta$ as a free parameter. Confronting it with the non-observation of high-energy
neutrinos from the Sun by the IceCube experiment, we obtain a robust limit, $\delta>566$\,keV. These limits exclude the interpretation of the recent LZ event in terms of endothermic inelastic scattering of Higgsino dark matter on xenon
nuclei.
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Materials Science
AlterSeeK-Path: Systematic construction of generalized band-structure paths for displaying altermagnetic spin splitting
Yujia Teng, Mesfin Eshete, Andrea Urru et al. (+4 more)
Altermagnetic materials exhibit
spin splitting in their electronic band structures while maintaining zero net magnetization. However, conventional high-
symmetry k-paths generally hide this splitting because they follow
symmetry lines that in most cases enforce
spin degeneracy. We present AlterSeeK-Path, an open-source Python tool that systematically constructs generalized band-structure paths for collinear altermagnets. The method selects the centroid of the conventional irreducible wedge used in routine band-structure calculations as the representative general k-point, maps it to a
spin-flip-related partner, and inserts paired segments through these points into the standard high-
symmetry path; these segments systematically sample the interior of the irreducible wedge. We demonstrate the construction for all 54 three-dimensional combinations of extended Bravais
lattice type and
spin Laue group across the six
crystal systems that support collinear altermagnetism, and for the 12 two-dimensional cases spanning the four compatible two-dimensional Bravais
lattices. Representative band structures are shown for the distinct
lattice/path cases. With AlterSeeK-Path, these band structures can be constructed with essentially the same effort as conventional band structures.
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All authors Yujia Teng, Mesfin Eshete, Andrea Urru, Daniel Seleznev, Se Young Park, Sebastian E. Reyes-Lillo, Karin M. Rabe
Mesoscale and Nanoscale Physics
Emergence of the magnetic octupole Rashba-Edelstein effect from spin-orbit entanglement
Hojun Lee and Seungyun Han
Magnetic multipoles have attracted growing interest as order parameters and dynamical degrees of freedom in unconventional magnets, yet it remains unclear how broadly they can emerge as active electronic degrees of freedom. Here, we show that
spin-orbit-entangled multiorbital states can host
magnetic octupole (MO) degrees of freedom. In Rashba systems, this gives rise to an MO Rashba texture accompanying the J-Rashba texture. Remarkably,
spin-orbital
entanglement can realize a pure-MO limit in which the
spin and orbital-angular-momentum textures vanish while the MO texture remains finite. An applied electric field converts this texture into a nonequilibrium MO polarization through an MO Rashba-Edelstein effect. Around the pure-MO regime, the MO Edelstein response dominates over the conventional
spin response, showing that multipolar responses need not be small corrections to dipolar
spin physics. Our results establish an interface-based route for electrically generating nonequilibrium multipolar
magnetic polarization in
spin-orbit-coupled systems.
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Materials Science
Systematic display of the spin splitting in band structures of representative altermagnetic crystals
Mesfin Eshete, Yujia Teng, Andrea Urru et al. (+4 more)
In this work we demonstrate a novel approach to exhibit the unique
spin splitting that is typical of collinear altermagnets. This approach is to plot band structures on Brillouin zone paths that sample general k-points to show a representative picture that corresponds to Brillouin zone averages. This is in contrast to conventional band structure plotting which plots band structures on the highest-
symmetry points and lines, and thus in many cases can fail to show any altermagnetic
spin splitting at all. Our investigation compares the new approach with the band structures of collinear altermagnets using conventional band structure plotting. We report the band structure and
symmetry analysis for MnTe, CrSb, SmFeO3, ScCrO3, LaMnO3, TlCrO3, HoFeO3, InCrO3 and DyFeO3. This result clearly demonstrates the advantage of this novel method for displaying the
spin splitting of collinear altermagnets.
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All authors Mesfin Eshete, Yujia Teng, Andrea Urru, Daniel Seleznev, Se Young Park, Sebastian E. Reyes-Lillo, Karin M. Rabe
Instrumentation and Methods for Astrophysics · Cross-listed from cs.LG
Do Tabular Foundation Models Know Physics? Contamination, Units, and the Deterministic Limit
Wassim Tenachi, Yashar Hezaveh, Laurence Perreault Levasseur et al. (+1 more)
Tabular foundation models (TFMs) learn to fill in tables the way
language models fill in text — and tables are arguably the format in which most physical measurement arrives. Did they learn any physics in the process? They are
Bayesian by construction, so the question is what their prior contains. We probe it directly, evaluating four of them ($\texttt{TabPFN-3}$, $\texttt{TabICLv2}$, $\texttt{TabDPT}$ and $\texttt{Real-TabPFN-2.5}$) against six baselines on
datasets sampled from 316 physical equations, in and out of domain. TFMs dominate, out of the box and after tuning. But they struggle to represent noiseless deterministic mechanisms in their uncertainty, and show no sign of exploiting physical units: they interpolate physics without yet being able to act as physical models.
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All authors Wassim Tenachi, Yashar Hezaveh, Laurence Perreault Levasseur, Pierre-Luc Bacon
Soft Condensed Matter
Relating solute interactions to interfacial properties
Varun Mandalaparthy, Benjamin M. Curlee and William G. Noid
Liquid interfaces are both ubiquitous and also critically important for many commercial products, modern technologies, biological processes, and environmental phenomena. The properties of these interfaces can depend quite sensitively upon the composition of the bulk
liquid phase. In this work, we develop a dilute solution theory (DST) for the influence of dilute cosolutes upon the interface between coexisting
liquid and vapor phases. We employ a grand canonical perturbation theory to rigorously relate the interfacial free energy to the concentration of the
liquid solution. We leverage a corresponding Gibbs ensemble to treat
liquid-vapor coexistence and to eliminate the contribution of the bulk phases from this free energy. We express the coefficients of the resulting expansion in terms of microscopic partition functions. By treating solute-solute interactions to lowest order, we distinguish between the intrinsic and effective interfacial preferences of solutes. While the former reflects only solute-solvent interactions, the latter depends upon the solution composition and reflects the influence of solute-solute interactions. We assess this DST with molecular dynamics simulations of binary and ternary mixtures of Lennard-Jones spheres. These simulations demonstrate that DST accurately models the interfacial properties of these systems up to relatively high concentrations. Moreover, the simulations illustrate the impact of attractive solute-solute interactions in converting weak intrinsic surfactants into weak effective depletants.
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High Energy Physics (Phenomenology)
Next-to-leading order QCD corrections to fully charm tetraquark hadronic decay
Yefan Wang, Fengxiang Zhao and Ruilin Zhu
We compute the next-to-leading order (NLO) QCD corrections to the light
hadron decays of fully charm tetraquarks within the nonrelativistic QCD (NRQCD) factorization framework. The short-distance coefficients for the $gg$ and $q\bar{q}$ final states from fully charm tetraquarks are obtained analytically. The NLO corrections are found to be significant, altering the LO predictions by about $170\%$ for the $0^{++}$ state and $30\%$ for the $2^{++}$ state. The resulting $\mathcal{R}_{\mathrm{LH}}$ values are of order $10^{-5}$ to $10^{-4}$ MeV, about three orders of magnitude larger than the diphoton channel, as expected for strong-interaction decays. Our results provide updated theoretical predictions for future experimental studies of fully charm tetraquark decays.
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Other Condensed Matter
Magnetoelectric Phase Transition and Axion Dynamics
Chen-Hui Xie, Runyu Lei, Jiayi Liu et al. (+4 more)
Magnetoelectric phase transitions have been experimentally studied, but no macroscopic theory has been proposed to explain their dynamical origin. In this work, we assume that the
axion quasiparticle with frequency undergoes a condensation like process. We show that these magnetoelectric phase transitions can be described within a Ginzbur Landau framework by introducing a coupled dynamic parameter, the
axion angle, which is proportional to the magnetoelectric coeffcient. We derive relations between the static
axion angle, the
axion frequency, and the phase transition temperature for different magnetoelectric materials, respectively, and compare these calculations with existing experimental results. We also connect the artificially designed Dzyaloshinskii Moriya interaction with the
axion condensate like process, so that the relation between the static
axion angle and the experimentally measured frequency shift can be obtained.
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All authors Chen-Hui Xie, Runyu Lei, Jiayi Liu, Yihuai Chen, Jinxing Zhang, Yu Gao, Sichun Sun
High Energy Physics (Phenomenology)
Next-to-Leading-Order Multi-Jet Merging of Higgs Boson Production via Vector Boson Fusion in the Presence of Anomalous Couplings
Tinghua Chen, Terrance Figy and Tunde Kushimo
We present the results of a detailed simulation study of
Higgs boson production via vector
boson fusion (VBF) at the Large
Hadron Collider (LHC) in the presence of anomalous couplings. The analysis utilizes the Herwig event generator interfaced with VBFNLO, employing a multi-jet merging scheme that combines NLO accurate
matrix elements for
Higgs plus 2- and 3-jet multiplicities with LO accurate
matrix elements for
Higgs plus 4-jet multiplicities. We investigate both matching and merging setups to consistently combine these hard scattering processes with QCD parton showers. Finally, we demonstrate the robustness of azimuthal angle observables against QCD radiative corrections across these frameworks.
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Cosmology and Nongalactic Astrophysics
Gravitational Imprints of Axion Clouds on Black-Hole Orbital Dynamics
J. Ruz, V. Mungai, F. Kühnel et al. (+4 more)
Black holes of
primordial or astrophysical origin immersed in
axion dark matter provide a natural laboratory for exploring the interplay between compact objects and ultralight scalar fields. While previous studies have primarily focused on superradiance and horizon-scale phenomena, the gravitational response of the surrounding
axion distribution has received comparatively little
attention. We investigate the dynamics of particles orbiting Schwarzschild and Kerr
primordial black holes embedded in scalar-field dark matter
halos. Using first-order perturbation theory, we show that the ambient
halo redistributes the gravitationally bound
axion cloud, shifting the characteristic radius of the gravitational atom. Numerical integrations of timelike geodesics demonstrate that the maximum orbital response consistently occurs at this perturbed radius, establishing a direct correspondence between the microscopic structure of the
axion wavefunction and the macroscopic dynamics of orbiting particles. Our results identify a new purely gravitational signature of scalar-field dark matter around
primordial black holes and provide a framework for probing mixed
axion–
primordial black hole dark matter scenarios.
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All authors J. Ruz, V. Mungai, F. Kühnel, C. Köhn, E. Stamou, J. K. Vogel, B. Guichard
Lattice Field Theory
Double Parton Distributions in the nucleon: Lattice parameter dependence
Daniel Reitinger, Christian Zimmermann and Andreas Schäfer
To make full use of the HL-LHC, especially in the search for BSM physics, all Standard Model backgrounds have to be understood with increased precision. This is especially difficult for Double Parton Interactions (DPIs) and more generally Multi Parton Interactions (MPIs), which are very difficult to isolate precisely in experiment. DPIs are parameterized by Double Parton Distributions (DPDs) and the
lattice determination of the latter is, therefore, especially attractive. In our previous work on DPDs on the
lattice, we focused on the results obtained from one gauge ensemble with higher than physical pion mass. In this work, we extend our efforts by investigating artifacts introduced by finite volume and the dependence on the
lattice spacing. Moreover, we consider the dependence on the mass parameters. This study is carried out by employing the Wilson-Clover
fermion gauge ensembles generated by the CLS collaboration.
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Chemical Physics
HiPoly: a hierarchical polymer-native AI framework for property prediction and generative design
Ge Sun, Gervasio Zaldivar, Yuan Tian et al. (+5 more)
Polymeric materials are central to modern technologies, with applications ranging from energy to health and transportation. Although AI has made significant advances in materials discovery, the hierarchical structure of
polymers across multiple length scales makes them inherently difficult to represent in a unified and physically meaningful way. Here we introduce HiPoly, a
polymer-native AI framework that processes complete
polymer descriptions through a three-level hierarchical graph architecture built on the G2RINS representation. HiPoly encodes
stochastic inter-monomer connectivity, composition, and molecular weight directly within its architecture, using physically motivated design principles that mirror the multi-scale nature of polymeric systems. The framework establishes an end-to-end AI-driven workflow from experimental formulation data to property prediction, generative molecular design, and physics-based validation through molecular simulations, all unified by a single
polymer representation. We demonstrate state-of-the-art prediction accuracy for thermophysical properties of multi-component
polymer systems, with ablation studies confirming that each hierarchical design choice contributes independently to model performance. As an example, the generative design pathway is applied here to the discovery of sustainable alternatives to persistent fluorinated
polymers, where it is possible to identify and independently validate PFAS-free candidates with target surface-energy properties. This work demonstrates how
polymer-native AI can accelerate discovery by linking representation, prediction, and design across complex
polymer chemistries.
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All authors Ge Sun, Gervasio Zaldivar, Yuan Tian, Gustavo Perez Lemus, Juhae Park, Daryna Safarian, Ming Han, Juan J. de Pablo
Materials Science
Understanding Graphene-Perovskite Interactions: From Flake Chemistry to Crystallisation and Solar Cell Performance
Oussama Er-Riyahi, Dorota Biernacka, Yating Guo et al. (+7 more)
Graphene-derivatives are widely employed materials to improve bulk and interface properties of metal-halide perovskite devices. Yet the implications of their flake chemistry and interactions with the perovskite precursors remain unclear. Here, we show that pristine
graphene flakes (GF) and more conventional
graphene oxide flakes (GOF) are not interchangeable. Density functional theory calculations reveal that GOF interacts more strongly with the perovskite
lattice but induces larger structural distortions, stronger interfacial polarisation, and localised gap states. In contrast, GF forms comparatively non-disruptive contacts, a response retained across a wide compositional range. Machine-learning atomistic simulations further show that GF contacts both Pb- and I-containing regions of solvated perovskite nanocrystals, with a strong solvent dependency. Solution spectroscopic characterization indicates that GF additives serve as scaffold for preorganised Pb/I-containing precursors, favouring film crystallisation. In this sense, GF enhances
solar cell performance across perovskite compositions, but particularly those facing a more challenging crystallisation. In mixed Sn-Pb perovskite
solar cells, GF raises the champion power-conversion efficiency from 21.5% to 23.7% with improved storage stability. These results establish pristine GF as a chemically defined additive and connect its atomic-scale interactions with precursor organisation, crystallisation, device performance, and stability.
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All authors Oussama Er-Riyahi, Dorota Biernacka, Yating Guo, Mikel Ballarena Tellechea, Silver-Hamill Turren-Cruz, Dario Bercioux, Meng Li, Agnieszka Lekawa-Raus, Jorge Pascual, Karolina Z. Milowska
Mathematical Physics · Cross-listed from math.PR
Sharp mean-field estimates for diffusive log/Riesz gases in the Hilbert–Schmidt regime
Matias G. Delgadino, Rishabh Gvalani and Matthew Rosenzweig
We study fixed-temperature logarithmic and Riesz gases after subtracting the leading mean-field contribution relative to a prescribed background law. For repulsive interactions in the
Hilbert–Schmidt regime, we prove $N$-uniform bounds and quantitative convergence of the resulting modulated partition function to a normalization expressed by the Carleman–Fredholm determinant of the centered interaction operator. We show that the
Hilbert–Schmidt threshold is sharp and obtain explicit lower bounds on the rate of divergence at and above it; these rates are expected to be nonoptimal. The proof combines positive-definite truncations and a low/high-frequency decomposition with exponential inequalities and Gaussian-chaos asymptotics for canonical degree-two $U$-statistics. As consequences, we establish entropic commutator estimates with the sharp $O(N^{-1})$ additive scale in the modulated-free-energy method, a static joint linear-statistics central limit
theorem, and a dynamical central limit
theorem for joint linear statistics at finitely many times. This extends the logarithmic partition-function estimates of the first two authors to the full Riesz
Hilbert–Schmidt range and identifies the limiting determinant normalization. For the attractive logarithmic interaction at sufficiently small inverse temperature, we also prove analogous results.
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High Energy Astrophysical Phenomena
An Exact Engine for Black-Hole Jets
Yu Wang
For fifty years the Blandford–Znajek mechanism has been a mechanism and not an exact solution: force-free electrodynamics on a prescribed metric, with the jet's own field carrying no weight. Here that field gravitates. A split monopole weighs as much as a
magnetic monopole, so its self-
gravity is the
magnetic Reissner–Nordström geometry; two copies glued across an equatorial current sheet put hole, disk and jet-driving flux into one spacetime, and force-free
plasma makes a magnetosphere of it. Three things then follow that no test-field calculation can see. First, a steady jet is impossible. A stationary horizon cannot be heated but a slipping magnetosphere necessarily heats it, so the only stationary state is a dead one corotating with the hole, and a working jet is a black hole in decay at rates the field equations fix rather than assume. Second, flux enters the laws of black-hole mechanics as a charge, sharing one extremality budget with
spin. That budget caps the jet power at $c^5/48G$ whatever the mass. Third, the lifetime output is finite: a maximally spinning hole delivers $1-e^{1/4}/\sqrt2=9.2\%$ of its mass and grows its horizon area by exactly $\sqrt e$. The horizon's own moment of inertia vanishes with the irrational exponent $(\sqrt{17}-1)/2$ set by the near-horizon throat, and what is left is a rotating hole whose angular momentum has passed to its own field.
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Quantum Physics
Spin squeezing by geometric focusing in vacuum Rabi oscillations
Aoqin Liang, Qi Liu and Guoqing Wang
We show that
vacuum Rabi oscillations can directly generate
spin squeezing through
geometric focusing on the Bloch sphere. Starting from a coherent
spin state resonantly coupled to a cavity initially in the
vacuum state,
quantum fluctuations are focused by the
curvature of the Bloch sphere as the collective
spin approaches the atomic ground state, producing squeezing transverse to the direction of motion. The squeezing timescale is set by the collective Rabi frequency $t_s\sim 1/(g\sqrt{N})$. The optimal Wineland squeezing parameter scales as $\xi_{\rm opt}^2\propto N^{-1/3}$, which is an outcome of the competition between the
geometric focusing effects and the cavity-field
vacuum fluctuations. The squeezing remains robust against realistic dissipation. In the end, an application example of $^{171}$Yb is briefly discussed to show the feasibility of our protocol.
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Mesoscale and Nanoscale Physics
QArray+: A physics-informed GPU-accelerated simulator for quantum dot arrays
Pranav Vaidhyanathan, Barnaby van Straaten, Alice Petrillo et al. (+6 more)
Semiconductor quantum-dot arrays are a compelling platform for scalable
quantum technologies, yet their practical operation is hindered by the complexity of tuning large-scale devices. Existing automation tools rely on simplified physical models—such as constant-capacitance approximations and
equilibrium Hubbard models—which assume instantaneous relaxation to a steady state. These frameworks fail in experimentally critical regimes where measurement rates exceed tunneling dynamics, necessitating more sophisticated non-
equilibrium control strategies. To bridge this gap, we introduce QArray+, an extension of the QArray framework that incorporates gate-dependent tunnel coupling and a
quantum open-system description of dissipative processes. This approach enables the unified simulation of coherent interdot charge-state hybridization and the non-
equilibrium latching dynamics essential for training robust machine-learning models for automated device operation. Implemented in JAX with GPU acceleration, QArray+ scales across GPUs and multi-node systems. For example, a charge stability diagram for a 100X100 grid of gate voltages over 64 dots can be computed in $\sim0.17\,\mathrm{s}$ on multiple GPUs. Since interdot interactions are short-ranged and the corresponding tuning corrections are local, simulations at these scales capture the physics relevant to even larger devices. These capabilities support high-throughput
dataset generation for automated device tuning.
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All authors Pranav Vaidhyanathan, Barnaby van Straaten, Alice Petrillo, Rahul Marchand, Edwin De Nicolo, Menno Veldhorst, Brucek Khailany, Taylor L. Patti, Natalia Ares
Optics
Optical Reservoir Computing with Structural Nonlinearity for Forecasting Chaotic Time Series
Leandro R. Venâncio, Jonathan Dong, Mickael Mounaix et al. (+1 more)
Optical computing offers a promising route to high-speed, energy-efficient information processing. However, implementing nonlinear operations typically requires strong light-matter interactions. Here, we introduce structural nonlinearity into an optical reservoir computing architecture, using only linear components. A digital micromirror device acts as a reconfigurable scattering potential, while the propagation of light through a scattering medium provides the high-dimensional mode mixing. By enforcing a second interaction with the wavefront shaper, we obtain a quadratic mapping of the input within the reservoir. A single experimental apparatus simultaneously implements conventional and structurally nonlinear reservoir architectures, enabling a direct comparison on
forecasting of the chaotic Mackey-Glass time series. We demonstrate that the structurally nonlinear reservoir improves short-term prediction accuracy and better preserves the long-term dynamics of the chaotic system, demonstrating the potential of structural nonlinearity for low-power optical computing.
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All authors Leandro R. Venâncio, Jonathan Dong, Mickael Mounaix, Jacopo Bertolotti
Earth and Planetary Astrophysics
Revisiting orbital recurrence in the dimmings of Boyajian's star (KIC~8462852)
Hector Socas-Navarro
KIC~8462852 (Boyajian's
star) shows deep, asymmetric, and highly irregular dimming events with no simple repetition pattern. A symmetric 1.1% transit detected by TESS in 2019 has been interpreted as a possible
giant planet or brown
dwarf, while the irregular dips are generally attributed to transiting
dust from exocomets or planetesimal fragments. We test whether the broader dip families may nevertheless recur orbitally. Our scenario assumes a major disruption that produced fragments with slightly different periods, causing successive returns to spread progressively in orbital phase. We compare this recurrent model with a null hypothesis of chronologically independent family centers, accounting for the observing window, and marginalize over the recurrence period $P$ and dispersion scale $\sigma_P$. We obtain $B_{10}=44.9$ in favor of recurrence, corresponding to “very strong” evidence on the Jeffreys scale. The maximum-likelihood solution is $P_{\rm ML}=781.6$~d and $\sigma_{P,\rm ML}=80.0$~d, close to the 776.1-d timescale obtained if D800 and the 2019 TESS event are separated by four revolutions. Independently of the timing fit, this period predicts a transit duration of about 20.5~h for the published
stellar and transit parameters, in close agreement with the observed $\sim21$~h. The result is conditional on the adopted
topology, priors, family definition, and observing selection function, and does not prove orbital recurrence. Nevertheless, the family timings strongly favor this specific recurrent-fragment model over independent occurrence, making progressive orbital phase dispersion a viable and physically motivated interpretation.
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Quantum Physics
Effective quasiparticle conserving Lindbladians in the thermodynamic limit
Lea Lenke and Kai Phillip Schmidt
Open
quantum many-body systems are commonly described by Lindblad master equations, yet the treatment of Lindbladian operators in the thermodynamic limit remains a major challenge. We develop a framework for constructing effective quasiparticle-conserving Lindbladian operators directly in the thermodynamic limit. Our approach extends continuous similarity transformations to non-Hermitian open
quantum systems and enables the systematic block diagonalization of Lindbladians with respect to the quasiparticle (qp) number. We formulate two complementary methods. The first, projective continuous similarity transformations (pcst++), generalizes perturbative continuous
unitary transformations to Lindblad operators so that a linked-cluster expansion allows us to obtain high-order series expansions of the infinite system. The second, deepCST, extends directly evaluated enhanced perturbative continuous
unitary transformations by combining the same qp-conserving generator with a perturbative truncation scheme that yields non-perturbative effective Lindbladian operators directly in thermodynamic limit. We apply pcst++ and deepCST to the dissipative transverse-field Ising chain with local dissipation. We focus on the low-Ising regime. We purify the Lindbladian by splitting each
spin into two sites. A
spin flip then corresponds to two qps. We derive and analyze the effective, qp-conserving Lindbladian in the sectors with zero to two qps. We show how the Ising interaction renormalizes the decay rates of elementary
spin-flip excitations and provides the microscopic mechanism for a competition between coherent interactions and dissipation. Our work establishes perturbative and non-perturbative continuous similarity transformations as a versatile tool for deriving effective qp pictures of open
quantum many-body systems in the thermodynamic limit.
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Mesoscale and Nanoscale Physics
Twist as a Mechanical Switch for Reconfigurable Stacking in h-BN
Gautham Vijayan, Zhaoheng Zhang, Kenji Watanabe et al. (+5 more)
Twistronics of layered materials has emerged as a highly active field due to its profound implications for
quantum electronics and materials engineering. However, the controllable manipulation of interlayer stacking remains a significant experimental challenge. Here, the homogeneous contact between hexagonal boron nitride layers is shown to be reproducibly switched between two distinct stable stacking configurations via an externally applied torque. Combining experiments and computational modelling, we identify the stacking order of these stable states as the commensurate AA and AB modes. These two states are associated with different rotational torque maxima, exhibiting an asymmetry ratio of 0.7, and distinct dynamics as a function of the twist angle. Moreover, the peak torque values scale linearly with contact area, highlighting the dominant role of edge elasticity in the twisting process. Given that the AA and AB stacking modes correspond to different out-of-plane electric polarization states, our findings offer a pathway for reconfigurable nano- and micro-electromechanical devices.
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All authors Gautham Vijayan, Zhaoheng Zhang, Kenji Watanabe, Takashi Taniguchi, Michael Urbakh, Oded Hod, Xiang Gao, Elad Koren
Statistical Mechanics
Optimal-work feedback on particles with activity — gliding on active fluctuations using positional information
Lars Torbjørn Stutzer and Sarah A. M. Loos
We study the minimum-work feedback control of particles subject to active fluctuations. Considering an active Ornstein-Uhlenbeck particle confined by a moving harmonic trap, we derive exact optimal protocols following an initial position measurement. Our results show that nonequilibrium correlations between position and active fluctuations allow work extraction from the activity based on positional information only, i.e., without directly measuring the active degree of freedom, which was the focus of earlier literature. We find that depending on the persistence time, activity can either facilitate or impede transport relative to passive systems. Surprisingly, unlike feedback schemes based on direct measurements of the active fluctuations, positional feedback remains energetically advantageous even in the limit of infinitely persistent activity. Our results provide design principles for information engines and optimal control strategies operating in active environments.
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Quantum Physics
Quantum amplitude estimation beyond power-of-two schedules
Farrokh Labib
Non-adaptive
quantum amplitude estimation (QAE) fixes its Grover depths in advance, so every
circuit can run in parallel, but it has so far needed more queries than the best adaptive methods. We show that most of this gap comes from two conventional choices: subspace-based post-processing and power-of-two depth ladders. We replace the first by the exact maximum-likelihood estimate, one
matrix multiplication per batch of estimates, and the second by a
geometric ladder with ratio $r \approx 1.45$. The result is a fully parallel, deterministic-schedule
estimator with total query complexity $2.8$-$3.1/\varepsilon$ at 95% confidence for target errors from $3.5\times 10^{-3}$ to $10^{-6}$. This matches the average-case complexity of chebAE, the best benchmarked adaptive method, within statistical uncertainty (with the lower point estimate at every scale tested), beats its maximum-observed complexity by $1.6\times$, and needs a maximum sequential depth of only $0.21/\varepsilon$ against chebAE's $2.9/\varepsilon$. Relative to csAE, the best non-adaptive
benchmark, the constants improve by 30-35% at 95% and $1.5$-$1.7\times$ at 99% confidence. The optimal ratio has a simple origin. Doubling is the fastest depth growth at which the data can still tell neighboring candidate values apart, so power-of-two ladders sit at the edge of confusion and must buy reliability with extra shots; a slightly denser ladder checks every scale redundantly. An error-probability analysis reproduces the measured failure rates and locates the optimum. The likelihood formulation extends directly to noise-aware estimation, and uniformly scaling the capped ladder covers the depth-limited regime, realizing the optimal trade-off $M N_{\mathrm{tot}} \approx (0.4$-$0.6)/\varepsilon^2$ within $\sim 1.1\times$ of the schedule's Cramér-Rao limit.
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Materials Science
From Goldene to Noblene: exhaustive enumeration of the ordered Au-Ag-Cu monolayer alloys
Marcelo Lopes Pereira Junior
Two-dimensional metals became a laboratory reality with the isolation of Goldene, a gold sheet one atom thick released by chemical exfoliation, which raises the question of what alloying can achieve on the same close-packed
lattice. Here we combine an exhaustive enumeration of derivative superstructures with density functional theory to map the ordered Au-Ag-Cu monolayer
alloys, relaxing every
symmetry-inequivalent arrangement up to four atoms per
cell and extending the set with larger
cells selected by a fitted model. We find that the arrangement of the atoms, and not their proportion, controls the mixing energy, since the spread among the orderings of a single composition is several times the step between neighboring compositions, one composition spans more than 50~meV/atom between two arrangements of the same three atoms, and at two compositions the arrangement decides the sign. The energetics is carried by a competition between Au-Cu contacts, which bind, and Ag-Cu contacts, which do not, and bulk enthalpies computed under the same protocol show that this chemistry is not uniformly rescaled in two dimensions, since Au-Cu orders more strongly in the monolayer than in the
crystal while the other two weaken. A pair model completed by an elastic size-mismatch term reproduces the computed energies to a few meV/atom and returns a composition landscape whose convex hull no balanced ternary composition reaches. One equimolar ordering, which we name Noblene, is the only structure in which every atom is surrounded exclusively by unlike species, and it is dynamically stable and metallic, and carries a Poisson's ratio above one half, higher than that of any of the three pure monolayers. Since Noblene sits on the
lattice that Goldene already realizes, the route that produced Goldene is a plausible starting point for its synthesis.
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Earth and Planetary Astrophysics
The Hill sphere transits of Beta Pictoris c and the search for another 1981-like event
V.E.C. Bakker, M.A. Kenworthy, R. Stuik et al. (+17 more)
Beta Pictoris is a young and nearby planetary system hosting an edge-on debris disk and at least three gas-
giant planets. Their circumplanetary environments could host exomoons and rings, a detection of which would be highly informative for moon and
planet formation theories. A photometric fluctuation of about 4% was seen towards Beta Pictoris in 1981, indicating the transit of
dust in the system, which could be associated with the Hill spheres of the two inner
planets. We search for the origin of the 1981 event by searching for an analogous event in multi-epoch photometry from 2017 to 2023, and look for signs of circumplanetary material in transits of the Hill sphere of Beta Pictoris c. Observations from the BRITE satellite, and the bRing and ASTEP observatories are fitted to a model of the 1981 event to search for a similar event, and also search for a signal consistent with a circumplanetary disk transit using a simple flat disk model. No compelling evidence for a 1981 event during a Hill sphere primary transit is found, although we do find a candidate event around 2019 July 26. Due to the uncertainty in the time of closest projected separation of Beta Pictoris c, a search for a disk during the primary transit of 2018 could not be robustly determined, but bRing photometry for the second primary transit places an upper limit on the
dust content of the Hill sphere of ~ $10^{22}$ grams of material. With no compelling detection of an event similar to that seen in 1981 during the transits of Beta Pictoris c in the photometric time series, we rule out the hypothesis that this event was related to the Hill spheres of Beta Pictoris c and Beta Pictoris b. Future observations of the next Hill sphere transit in 2028 can be realised with both ground-based observatories and with PLATO, whose first long duration science pointing will include Beta Pictoris.
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All authors V.E.C. Bakker, M.A. Kenworthy, R. Stuik, K. Zwintz, T. Guillot, S. Vach, J. Wang, J. Kammerer, W. Balmer, S. Lacour, S. Zieba, E.E. Mamajek, G.-D. Marleau, R.B. Kuhn, P. Kalas, Y. De Pra, E.J.W. de Mooij, N. Crouzet, M. Buttu, J.I. Bailey III
High Energy Physics (Theory) · Cross-listed from math.GT
Samuel Panitch and Mauricio Romo
Using the newly developed $3$d
quantum trace map, we compile more evidence for the length
conjecture, a refinement of the all-order volume
conjecture that incorporates insertions of additional links in the skein module of the
knot complement. In particular, we prove that the length
conjecture holds up to first order for an infinite family of twist
knots. Along the way, we form a
conjecture that the $3$d
quantum trace map behaves naturally with respect to Dehn filling.
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Nuclear Theory
Halo-EFT: an effective and efficient tool to study reactions with halo nuclei
Quentin Bozet, Live-Palm Kubushishi and Pierre Capel
Halo nuclei are exotic
nuclei, which exhibit a much larger matter radius than their isobars. This unusual size is now understood as a threshold effect, in which one or two valence nucleons are loosely bound to the core of the
nucleus. Thanks to this loose binding,
halo nuclei exhibit a strongly clusterised structure with a diffuse
neutron halo surrounding a compact core. Being short lived,
halo nuclei are mostly studied through reactions, such as breakup. In this talk we show that including
Halo Effective Field Theory within existing reaction codes is both effective and efficient to analyse experimental data. We first apply this idea to study the Coulomb breakup of 19C within a
Bayesian approach. Second, we extend
Halo-EFT to include the core's excitation to test the sensitivity of the Coulomb breakup of 11Be on spectroscopic factors.
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Optics
Random-mapped intensity optical neural network: all-optical two-layer computing for multimodal optical-field inference
Gi-Hyun Go, Doeon Lee, Gookho Song et al. (+1 more)
Free-space optical neural networks offer distinct advantages for computational imaging and machine
vision because they can compute directly on incident optical fields. However, conventional ONNs composed of cascaded linear optical components are bound to a general linear input-output relation with square-law detection between the input field $\mathbf{x}$ and output score $\mathbf{y}$, $\mathbf{y}=|\mathbf{T}\mathbf{x}|^2$, where at best every complex-valued element of the transmission
matrix $\mathbf{T}$ is trainable. This restricts each output score to a quadratic form $\mathbf{x}^\dagger\mathbf{A}\mathbf{x}$ with rank-one decision
matrix $\mathbf{A}=\mathbf{t}^\dagger\mathbf{t}$. Here, we present a random-mapped intensity optical neural network (RMI-ONN) as an all-optical two-layer computational network that lifts this rank-one limit. We numerically demonstrate that a high-dimensional feature projection by a disordered medium, a programmable nonnegative intensity mask, and segmented spatial power summation together can surpass the rank-one ceiling through the expressivity of higher-rank quadratic decision boundaries. Furthermore, exploiting the vectorial coherent wave-mixing nature of the disordered medium, we experimentally validate
multimodal classification of amplitude, phase, and polarization on MNIST, Fashion-MNIST, and Quick Draw with the RMI-ONN, under a single optical configuration across all encoding domains. These results provide a practical and conceptual basis for scalable direct-field optical processors capable of exploiting amplitude, phase, and polarization information within a unified intensity-based inference framework.
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All authors Gi-Hyun Go, Doeon Lee, Gookho Song, Mooseok Jang
Biological Physics
A viscoelastic theory for ultrasound-induced intracellular streaming
Niels Gieseler, Falko Ziebert and Ulrich S. Schwarz
Ultrasound is increasingly used to control biological
cells, but its multiple physical effects, including radiation force, streaming, heating, and cavitation, require theoretical frameworks that can quantify their relative strengths. Here we develop a semi-analytical model to predict flow patterns and energy distributions of ultrasound-induced intracellular streaming.
Cells are modeled as viscoelastic droplets immersed in a fluid with different viscoelastic properties. For this geometry, the momentum equation with an Oldroyd-B constitutive law is solved using a perturbation expansion commonly applied in acoustofluidics. The resulting equations for the different orders of the expansion are solved using partial wave expansion and explicit integration. We investigate our model for a range of parameters which is relevant both for synthetic
polymer and for
protein solutions. We find a series of flow reversals that we can connect to the distribution of energy into the different modes. We also consider density and compressibility contrasts, which shift these transitions and introduce new ones. Finally, we discuss the potential biological relevance of our mathematical results for cellular sensing and signaling.
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Computational Physics
RBMD 2.0: Random batch molecular dynamics package for large-scale simulations on multi-GPU architectures
Qi Zhou, Yongfa Guo, Jincheng Zhong et al. (+3 more)
Large-scale molecular dynamics simulations of particle systems on multi-GPU architectures are often constrained by the computational and communication costs of nonbonded force evaluation. We present RBMD 2.0, a major new release of the random batch molecular dynamics package designed for cross-node multi-GPU simulations of large-scale systems. It combines the improved random batch Ewald method with three-dimensional domain decomposition and ghost-particle communication to accelerate multi-GPU nonbonded force evaluation, while the DTK CUDA framework facilitates portability across heterogeneous accelerator architectures. Numerical experiments on multiple
benchmark systems demonstrate both the accuracy and efficiency of simulations with RBMD 2.0. For simulations involving up to hundreds of millions of particles across multiple accelerator devices, one achieves speedups ranging from severalfold to approximately two orders of magnitude in nonbonded force evaluation while exhibiting over $97.5\%$ weak-scaling behavior. These results demonstrate the promising nature of RBMD 2.0 as a computational engine for future exascale molecular dynamics simulations.
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All authors Qi Zhou, Yongfa Guo, Jincheng Zhong, Shou-Hang Bo, Teng Zhao, Zhenli Xu