arXivDaily arXiv每日学术速递 周一至周五更新
2602.10110 2026-02-11 quant-ph cond-mat.str-el

Anyon Permutations in Quantum Double Models through Constant-depth Circuits

Yabo Li, Zijian Song

详情
英文摘要

We provide explicit constant-depth local unitary circuits that realize general anyon permutations in Kitaev's quantum double models. This construction can be naturally understood through a correspondence between anyon permutation symmetries of two-dimensional topological orders and self-dualities in one-dimensional systems, where local gates implement self-duality transformations on the boundaries of microscopic regions. From this holographic perspective, general anyon permutations in the $D(G)$ quantum double correspond to compositions of three classes of one-dimensional self-dualities, including gauging of certain subgroups of $G$, stacking with $G$ symmetry-protected topological phases, and outer automorphisms of the group $G$. We construct circuits realizing the first class by employing self-dual unitary gauging maps, and present transversal circuits for the latter two classes.

2602.10091 2026-02-11 cond-mat.str-el cond-mat.dis-nn cond-mat.quant-gas

Simulating superconductivity in mixed-dimensional $t_\parallel$-${J}_\parallel$-${J}_\perp$ bilayers with neural quantum states

Hannah Lange, Ao Chen, Antoine Georges, Fabian Grusdt, Annabelle Bohrdt, Christopher Roth

Comments 7 pages + Supplementary Materials

详情
英文摘要

Motivated by the recent discovery of superconductivity in the bilayer nickelate La$_3$Ni$_2$O$_7$ (LNO) under pressure, we study a mixed-dimensional (mixD) bilayer $t_\parallel$-$J_\parallel$-$J_\perp$ model, which has been proposed as an effective low-energy description of LNO. Using neural quantum states (NQS), and in particular Gutzwiller-projected Hidden Fermion Pfaffian State, we access the ground-state properties on large lattices up to $8\times 8\times 2$ sites. We show that this model exhibits superconductivity across a wide range of dopings and couplings, and analyze the pairing behavior in detail. We identify a crossover from tightly bound, Bose-Einstein-condensed interlayer pairs at strong interlayer exchange to more spatially extended Bardeen-Cooper-Schrieffer-like pairs as the interlayer exchange is decreased. Furthermore, upon tuning the intralayer exchange, we observe a sharp transition from interlayer $s$-wave pairing to intralayer $d$-wave pairing, consistent with a first-order change in the pairing symmetry. We verify that our simulations are accurate by comparing with matrix product state simulations on coupled ladders. Our results represent the first simulation of a fermionic multi-orbital system with NQS, and provide the first evidence for superconductivity in two-dimensonal bilayers using high-precision numerics. These findings provide insight into superconductivity in bilayer nickelates and cold atom quantum simulation platforms.

2602.10088 2026-02-11 hep-lat hep-th math.AT

Simplicity of confinement in SU(3) Yang-Mills theory

Xavier Crean, Jeffrey Giansiracusa, Biagio Lucini

Comments 16 pages, 17 figures, 2 tables

详情
英文摘要

We introduce a novel observable associated to Abelian monopole currents defined in the Maximal Abelian Projection of SU(3) Yang-Mills theory that captures the topology of the current loop. This observable, referred to as the $\textit{simplicity}$, is defined as the ratio of the zeroth over the first Betti number of the current graph for a given field configuration. A numerical study of the expectation value of the simplicity performed in the framework of Lattice Gauge Theories enables us to determine the deconfinement temperature to a higher degree of accuracy than that reached by conventional methods at a comparable computational effort. Our results suggest that Abelian current loops are strongly correlated with the degrees of freedoms of the theory that determine confinement. Our investigation opens new perspectives for the definition of an order parameter for deconfinement in Quantum Chromodynamics able to expose the potentially rich phase structure of the theory.

2602.10087 2026-02-11 physics.chem-ph cond-mat.soft cond-mat.stat-mech

Theory for enzymatic degradation of semi-crystalline polymer particles

Michael Schindler, Hernan Garate, Ludwik Leibler

Comments This document is the unedited author's version of a submitted manuscript subsequently accepted for publication in 'Macromolecules'

详情
英文摘要

In enzymatic recycling or biodegradation of semi-crystalline plastic waste, crystalline spherulites embedded into an amorphous matrix hinder and slow down depolymerisation. When the enzymatic depolymerisation temperature exceeds the glass transition temperature, these spherulites tend to grow. The depolymerisation process is thus controlled by a competition between erosion of the amorphous matrix from the particle surface and the growth of recalcitrant spherulites within the particle bulk and at its surface. We present a geometric model that captures this competition, together with an algorithm to solve the equations numerically. Our algorithm introduces a new extension of Voronoi/Delaunay tessellation in space. We extract the parameters for the model from experimental data on the enzymatic depolymerization by hydrolase LCC-ICCG of PET bottle flakes and textile waste, in order to make a prediction of the observed degradation yield as a function of time. Both the final yield and the degradation kinetics are correctly predicted. Most importantly, the model clarifies how and to which extent nucleating agents, impurities, additives, and/or rapid crystal growth present in the waste can undermine pretreatment efforts aiming to initiate depolymerisation from a material with a low initial crystallinity.

2602.10086 2026-02-11 cond-mat.str-el

Canonical strong coupling spin wave expansion of Kondo lattice magnets. II. Itinerant ferromagnets and topological magnon bands

M. Frakulla, J. Strockoz, D. S. Antonenko, J. W. F. Venderbos

Comments 12 pages; 8 figures; 1 appendix. Companion paper to arXiv:2408.16665

详情
英文摘要

In this paper we apply the canonical spin wave theory developed for itinerant Kondo lattice magnets in the strong coupling regime to Kondo ferromagnets, and address two general questions pertaining to their magnetic excitations. First, we compute corrections to the strong coupling (i.e., double-exchange) spin wave dispersion of itinerant ferromagnets. We show that the spin wave dispersion beyond the strong coupling limit can be mapped to the spin wave dispersion of a Heisenberg ferromagnet with farther neighbor exchange couplings, and discuss how this affects instabilities towards antiferromagnetism. Second, we examine the effect of including electronic spin-orbit coupling in the spin wave theory of Kondo ferromagnets. Including spin-orbit coupling is natural and straightforward in the formulation of the canonical spin wave expansion. Our key result is to demonstrate that the linear spin wave Hamiltonian of the itinerant Kondo ferromagnet can be mapped to the spin wave Hamiltonian of a Heisenberg ferromagnet with easy-axis Ising anisotropy and antisymmetric Dzyaloshinskii-Moriya exchange interaction. We show that in the case of the Kane-Mele honeycomb lattice Kondo ferromagnet this leads to topological magnon bands, and discuss the implications of this result for itinerant ferromagnets more broadly.

2602.10084 2026-02-11 astro-ph.SR astro-ph.GA astro-ph.HE

Narrow absorption lines from intervening material in supernovae. IV. Type Ia supernovae: Na I D line strength relating to external material and intrinsic properties

Santiago González-Gaitán, Claudia P. Gutiérrez, João Duarte, Rita Santos, Gonçalo Martins, Joseph P. Anderson, Lluís Galbany

详情
英文摘要

Type Ia supernovae (SNe Ia) are thermonuclear runaways in certain white dwarfs in binary systems. They have been extensively studied, yet their progenitor and explosion mechanisms remain poorly understood. We study a large sample of SNe Ia comparing the narrow interstellar absorption features in their spectra with various photometric and spectroscopic supernova properties, as well as with environmental characteristics. We find that the sodium absorption is significantly stronger in younger, more star-forming and more centrally located SNe Ia, as expected. However, we also show that there is a strong dependence on intrinsic properties that is independent of the environment. In fact, we find strong evidence for two environmental SN Ia populations, an old and a young one, with the young population showing significantly different distributions of sodium strength when divided according to the Si II ejecta velocity, nebular velocity, extinction, E(B-V), and reddening curve, RV. Performing a clustering of the SNe Ia, we recover an old population of SNe with low extinction and normal ejecta velocity, while we confirm that the young population can be subdivided into a group of highly-extincted, high-velocity SNe Ia with much stronger blueshifted sodium absorption, and another of low-extincted, normal-velocity objects with little sodium absorption. We interpret this relation of intervening material with intrinsic properties as evidence for the young SN Ia population, occurring in young and star-forming environments, to have asymmetric radiation that interacts with nearby material, and whose observables depend thus on the viewing angle. Finally, we show that the cosmological mass-step is consistent with these populations.

2602.10082 2026-02-11 astro-ph.GA

Effects of Numerical Resolution on Simulated Cloud-Wind Interactions

Hannah Leary, Helena M. Richie, Evan Schneider

Comments 14 pages, 7 figures, accepted for publication in ApJ

详情
英文摘要

Mixing by hydrodynamical instabilities plays a key role in cloud-wind interactions, causing cloud destruction in the adiabatic limit and facilitating cloud survival with efficient radiative cooling. However, the rate of mixing in numerical simulations is sensitive to the smallest resolved scale, and the relationship between resolution and cloud evolution is under-explored. Using a set of cloud-crushing simulations, we investigate the effects of numerical resolution on cloud survival and acceleration. Modeling both adiabatic and radiative cases, in a subsonic and supersonic wind, we find that cloud survival and velocity does depend on the numerical resolution, however, no single resolution requirement can be applied to all scenarios. In the radiative subsonic case, we find that mass growth and acceleration appear converged at only 4 cells per cloud radius. Conversely, in the supersonic regime, we see a clear dependence of cloud destruction and velocity on resolution that is not converged even at 48 cells per cloud radius, implying that accurately capturing cloud destruction may require higher resolution than capturing growth. We also present a simple model illustrating how ram pressure accelerates cool clouds at early times before mixing kicks in as an acceleration mechanism.

2602.10078 2026-02-11 astro-ph.CO hep-ph

Constraining long-lived dark sector particles with CMB and Lyman-$α$

Laura Lopez-Honorez, Sonali Verma

Comments 12 pages, 7 figures

详情
英文摘要

We use measurements of the intergalactic medium (IGM) temperature from the Lyman-$α$ forest to place new limits on models in which long-lived dark sector (DS) particles, with lifetimes longer than $10^{16}$ s, deposit energy into the IGM through their decays. Such DS decays into Standard Model (SM) states can modify the late-time thermal history of the IGM, making Lyman-$α$ data a sensitive probe of hidden sectors with cosmologically long lifetimes. Our analysis demonstrates that constraints from late-time IGM heating offer a complementary window to those from the Cosmic Microwave Background (CMB), in constraining dark sector parameter space. We further revisit limits on such decaying DS models from Planck's measurements of the optical depth to reionization and provide updates relevant for DS lifetimes longer than $10^{14}$ s. The model-independent constraints on the DS parameter space we derive in this work can be reinterpreted for a wide range of decaying hidden-sector scenarios, including evaporating primordial black holes and SM-coupled dark photons.

2602.10076 2026-02-11 cond-mat.str-el

Orbital piezomagnetic polarizability of pure insulating altermagnets in two dimensions

Beryl Bell, Jörn W. F. Venderbos

Comments 11 pages; 9 figures; 3 appendices

详情
英文摘要

The distinctive symmetry properties of pure altermagnets make them natural candidates for piezomagnetism. Previous work motivated by the piezomagnetic properties of altermagnets has primarily focused on the spin magnetization response to applied strain. In this paper we study orbital piezomagnetic effects--the orbital magnetization response to applied strain--in minimal lattice models of pure insulating altermagnets in two dimensions. We obtain general microscopic expressions for the orbital magnetization in the presence of strain, as well as the orbital piezomagnetic polarizability, i.e., the defining response characteristic of pure altermagnets. We apply these expressions to three specific tetragonal lattice models, two corresponding to $d$-wave altermagnets and one describing a $g$-wave altermagnet. Whereas the $d$-wave altermagnets are associated with a linear piezomagnetic polarizability, the $g$-wave altermagnet exhibits a nonlinear piezomagnetic effect. Our analysis reveals how the polarizabilities are related to and determined by the Berry curvature of the occupied bands. Connections to materials of current interest are discussed.

2602.10075 2026-02-11 hep-ph hep-ex hep-lat

Tensor states $ΥB_{c}^{\ast -}$ and $J/ψB_{c}^{\ast +}$

S. S. Agaev, K. Azizi, H. Sundu

Comments 11 Pages, 5 Figures and 1 Table

详情
英文摘要

Tensor states $\mathcal{M}_{\mathrm{T}}^{\mathrm{b}}=ΥB_{c}^{\ast -}$ and $\mathcal{M}_{\mathrm{T}}^{\mathrm{c}}=J/ψB_{c}^{\ast +}$ are explored using techniques of QCD sum rule method. These hadronic molecules, composed of only heavy quarks, have asymmetric quark contents $bb\overline{b} \overline{c}$ and $cc\overline{c}\overline{b}$, respectively. The masses $ m=(15864 \pm 85)~\mathrm{MeV} $ and $\widetilde{m}=(9870 \pm 82)~\mathrm{MeV} $ prove that these structures are unstable against dissociations to constituent mesons. Full widths of molecules $\mathcal{M}_{\mathrm{T}}^{ \mathrm{b}}$ and $\mathcal{M}_{\mathrm{T}}^{\mathrm{c}}$ are calculated by considering their dominant and subleading decay channels. The subleading channels are processes generated by annihilations of $\overline{b}b$ and $ \overline{c}c$ quarks. For the molecule $\mathcal{M}_{\mathrm{T}}^{\mathrm{b} }$ dominant decays are $\mathcal{M}_{\mathrm{T}}^{\mathrm{b}} \to ΥB_{c}^{\ast -}$ and $\mathcal{M}_{\mathrm{T}}^{\mathrm{b}} \to η_b B_{c}^{-}$, whereas subleading channels are transformations to $\mathcal{M}_{ \mathrm{T}}^{\mathrm{b}}\rightarrow B^{(\ast )-}\overline{D}^{(\ast )0}$ and $\overline{B}_{(s)}^{(\ast )0}D_{(s)}^{(\ast )-}$ mesons. In the case of $ \mathcal{M}_{\mathrm{T}}^{\mathrm{c}}$ we explore decays to $J/ψB_{c}^{\ast +}$, $η_{c}B_{c}^{+}$, $B^{(\ast)+}D^{(\ast )0}$ and $ B_{(s)}^{(\ast )0}D_{(s)}^{(\ast )+}$ mesons. Predictions $Γ[\mathcal{M} _{\mathrm{T}}^{\mathrm{b}}]=120^{+17}_{-12}~ \mathrm{MeV} $ and $Γ[ \mathcal{M}_{\mathrm{T}}^{\mathrm{c}}]=(71 \pm 9)~ \mathrm{MeV} $ for the widths of these molecules characterize them as relatively broad structures.

2602.10072 2026-02-11 astro-ph.GA

SDSS-V Local Volume Mapper (LVM): Helix Nebula public data, Data Analysis Pipeline data products

S. F. Sánchez, J. E. Méndez-Delgado, A. Mejía-Narváez, C. Román-Zuñiga, O. V. Egorov, C. Morisset, N. Drory, G. A. Blanc, K. Kreckel, E. J. Johnston, Ivan Yu. Katkov, A. Roman Lopes, M. A. Villa-Durango, H. Ibarra-Medel, H. -W. Rix, R. de J. Zermeño, J. G. Fernández Trincado, A. Singh, P. García, G. S. Stringfellow, L. Sabin, J. Toalá, R. Orozco Duarte, A. M. Jones

Comments 20 pages, 12 figures, accepted for publishing in RMxA&A

详情
英文摘要

We present a spatially resolved spectroscopic analysis of the Helix Nebula (NGC 7293) using data from the SDSS-V Local Volume Mapper (LVM), by applying the recently developed LVM Data Analysis Pipeline (LVM-DAP). Covering the full optical range (3600-9800 Å) over a contiguous ~ 0.5 degree field, the LVM data provide the first hexagonally sampled, wide-field emission-line maps of all major ionic species in this archetypal planetary nebula. The resulting flux, kinematic, and line-ratio maps reveal the well-known ionization stratification of the nebula, from the compact He++ core to the bright [O III] ring and the extended low-ionization envelope, enabling a detailed comparison with classical aperture spectroscopy. Owing to the sensitivity and uniform spatial sampling of the LVM, numerous faint auroral and diagnostic lines are detected across the nebula, including [O III] 4363, [N II] 5755, and He I lines, allowing precise measurements of weak-line morphology. The derived radial trends confirm the remarkably low dust content and the overall homogeneity of electron temperature and density across the main ring. Ionized-gas kinematics traced by Hα further support the scenario of a slowly expanding, limb-brightened shell consistent with previous studies. This work demonstrates the diagnostic power of LVM spectroscopy for extended nebulae and highlights its capability to recover both global and spatially resolved physical conditions across complex ionized structures.

2602.10066 2026-02-11 physics.optics

Programmable and nonvolatile computing with composition tuning in thin film lithium niobate

Abhiram Devata, Axel Magaña Ponce, David Barton

Comments 20 pages, 4 figures

详情
英文摘要

Matrix-vector multiplications are fundamental operations in artificial intelligence and high-throughput computations, and are executed repeatedly during training and inference. Their high energy cost in electronic processors motivate scalable photonic computing approaches that reduce the energy required per operation. Thin film lithium niobate (TFLN) is a dominant photonic platform due to its large electro-optic effect. However, it lacks nonvolatile index tuning mechanisms, which promise to pave the way for energy-efficient photonic computing. Here, we explore electrochemical lithiation as a route to nonvolatile matrix-vector multiplications in TFLN. The LiNbO3 phase is stable at room temperature over a 2% Li composition window with an associated composition-dependent refractive index. We computationally demonstrate this as a programmable, low-loss approach to perform matrix-vector multiplications by using composition to control matrix weights. We design Mach-Zehnder interferometers to perform image processing tasks under realistic material loss constraints. We also design microring resonators for iterative weight updates, using gradient descent training to program target matrix operations with matrix-vector multiplication accuracy validated at 1.5% average relative error. These demonstrations show a facile route towards nonvolatile photonic computing in TFLN, addressing a critical requirement for energy-efficient photonic matrix operations at scale.

2602.10065 2026-02-11 astro-ph.CO

Dark Energy Survey Year 6 Results: Cosmological Constraints from Cosmic Shear

DES Collaboration, T. M. C. Abbott, M. Aguena, A. Alarcon, O. Alves, A. Amon, D. Anbajagane, F. Andrade-Oliveira, W. d'Assignies, S. Avila, D. Bacon, J. Beas-Gonzalez, K. Bechtol, M. R. Becker, G. M. Bernstein, J. Blazek, S. Bocquet, D. Brooks, H. Camacho, G. Camacho-Ciurana, R. Camilleri, G. Campailla, A. Campos, A. Carnero Rosell, M. Carrasco Kind, J. Carretero, F. J. Castander, R. Cawthon, C. Chang, A. Choi, J. M. Coloma-Nadal, C. Conselice, L. N. da Costa, M. Costanzi, M. Crocce, T. M. Davis, J. De Vicente, D. L. DePoy, J. DeRose, S. Desai, H. T. Diehl, P. Doel, C. Doux, A. Drlica-Wagner, T. F. Eifler, S. Everett, A. E. Evrard, A. Ferté, B. Flaugher, P. Fosalba, O. Friedrich, J. Frieman, J. García-Bellido, M. Gatti, G. Giannini, P. Giles, K. Glazebrook, D. Gruen, R. A. Gruendl, G. Gutierrez, I. Harrison, W. G. Hartley, K. Herner, S. R. Hinton, D. L. Hollowood, K. Honscheid, D. Huterer, B. Jain, D. J. James, M. Jarvis, N. Jeffrey, T. Jeltema, T. Kacprzak, S. Kent, E. Krause, O. Lahav, S. Lee, E. Legnani, H. Lin, J. L. Marshall, S. Mau, J. Mena-Fernández, F. Menanteau, R. Miquel, J. J. Mohr, J. Muir, J. Myles, R. C. Nichol, R. L. C. Ogando, A. Palmese, M. Paterno, W. J. Percival, D. Petravick, A. A. Plazas Malagón, A. Porredon, J. Prat, C. Preston, M. Raveri, M. Rodriguez-Monroy, A. K. Romer, A. Roodman, E. S. Rykoff, S. Samuroff, C. Sánchez, E. Sanchez, D. Sanchez Cid, T. Schutt, I. Sevilla-Noarbe, E. Sheldon, T. Shin, M. E. da Silva Pereira, M. Smith, M. Soares-Santos, E. Suchyta, M. E. C. Swanson, M. Tabbutt, G. Tarle, D. Thomas, C. To, M. A. Troxel, V. Vikram, M. Vincenzi, N. Weaverdyck, J. Weller, P. Wiseman, M. Yamamoto, B. Yanny, B. Yin, J. Zuntz

Comments See this https://www.darkenergysurvey.org/des-y6-cosmology-results-papers/ for the full DES Y6 3x2pt cosmology release

详情
英文摘要

We present legacy cosmic shear measurements and cosmological constraints using six years of Dark Energy Survey imaging data. From these data, we study ~140 million galaxies (8.29 galaxies/arcmin$^2$) that are 50% complete at i=24.0 and extend beyond z=1.2. We divide the galaxies into four redshift bins, and obtain cosmic shear measurement with a signal-to-noise of 83, a factor of 2 higher than the Year 3 analysis. We model the uncertainties due to shear and redshift calibrations, and discard measurements on small angular scales to mitigate baryon feedback and other small-scale uncertainties. We consider two fiducial models to account for the intrinsic alignment (IA) of the galaxies. We conduct a blind analysis in the context of the $Λ$CDM model and find $S_8 \equiv σ_8(Ω_m/0.3)^{0.5}=0.798^{+0.014}_{-0.015}$ (marginalized mean with 68% CL) when using the non-linear alignment model (NLA) and $S_{8} = 0.783^{+0.019}_{-0.015}$ with the tidal alignment and tidal torque model (TATT), providing 1.8% and 2.5% uncertainty on $S_8$. Compared to constraints from the cosmic microwave background from Planck 2018, ACT DR6 and SPT-3G DR1, we find consistency in the full parameter space at 1.1$σ$ (1.7$σ$) and in $S_8$ at 2.0$σ$ (2.3$σ$) for NLA (TATT). The result using the NLA model is preferred according to the Bayesian evidence. We find that the model choice for IA and baryon feedback can impact the value of our $S_8$ constraint up to $1σ$. For our fiducial model choices, the resultant uncertainties in $S_8$ are primarily degraded by the removal of scales, as well as the marginalization over the IA parameters. We demonstrate that our result is internally consistent and robust to different choices in calibrating the data, owing to methodological improvements in shear and redshift measurement, laying the foundation for next-generation cosmic shear programs.

2602.10064 2026-02-11 cond-mat.mtrl-sci physics.comp-ph

PySlice: Routine Vibrational Electron Energy Loss Spectroscopy Prediction with Universal Interatomic Potentials

Harrison A. Walker, Thomas W. Pfeifer, Paul M. Zeiger, Jordan A. Hachtel, Sokrates T. Pantelides, Eric R. Hoglund

详情
英文摘要

Vibrational spectroscopy in the electron microscope can reveal phonon excitations with nanometer spatial resolution, yet routine prediction remains out of reach due to fragmented workflows requiring specialized expertise. Here we introduce PySlice, the first publicly available implementation of the Time Autocorrelation of Auxiliary Wavefunction (TACAW) method, providing an automated framework that produces momentum- and energy-resolved vibrational electron energy-loss spectra directly from atomic structures. By integrating universal machine learning interatomic potentials with TACAW, PySlice eliminates the bottleneck of per-system potential development. Users input atomic structures and obtain phonon dispersions, spectral diffraction patterns, and spectrum images through a unified workflow spanning molecular dynamics, GPU-accelerated electron scattering, and frequency-domain analysis. We outline the formulation behind the code, demonstrate its application to canonical systems in materials science, and discuss its use for advanced analysis and materials exploration. The modular Python architecture additionally supports conventional electron microscopy simulations, providing a general-purpose platform for imaging and diffraction calculations. PySlice makes vibrational spectroscopy prediction routine rather than specialized, enabling computational screening for experimental design, systematic exploration of phonon physics across materials families, and high-throughput generation of simulated data for training of future machine learning models.

2602.10061 2026-02-11 math.AP physics.ao-ph

Confinement results near point vortices on the rotating sphere

Martin Donati, Emeric Roulley

Comments 46 pages

详情
英文摘要

We study the Euler equation on the rotating sphere in the case where the absolute vorticity is initially sharply concentrated around several points. We follow the literature already concerning vorticity confinement for the planar Euler equations, and obtain similar results on the rotating sphere, with new challenges due to the geometry. More precisely, we show the improbability of collisions for point-vortices, logarithmic in time absolute vorticity confinement for general configurations, the optimality of this last result in general, and the existence of configurations with power-law long confinement. We take this opportunity to write a unified, self-contained, and improved version of all the proofs, previously scattered across multiple papers on the planar case, with detailed exposition for pedagogical clarity.

2602.10060 2026-02-11 cond-mat.dis-nn

Early warning signals for phase transitions in networks

A. V. Goltsev, S. N. Dorogovtsev

Comments 12 pages

详情
英文摘要

The percolation phase transition in complex network systems attracts much attention and has numerous applications in various research fields. Finite size effects smooth the transition and make it difficult to predict the critical point of appearance or disappearance of the giant connected component. For this end, we introduce the susceptibility of arbitrary random undirected and directed networks and show that a strong increase of the susceptibility is the early warning signal of approaching the transition point. Our method is based on the introduction of `observers', which are randomly chosen nodes monitoring the local connectivity of a network. To demonstrate efficiency of the method, we derive explicit equations determining the susceptibility and study its critical behavior near continuous and mixed-order phase transitions in uncorrelated random undirected and directed networks, networks with dependency links, and $k$-cores of networks. The universality of the critical behavior is supported by the phenomenological Landau theory of phase transitions.

2602.10041 2026-02-11 physics.plasm-ph

Design of experiments characterising heat conduction in magnetised, weakly collisional plasma

T. A. Vincent, P. Ariyathilaka, L. Creaser, C. Danson, D. Lamb, J. Meinecke, C. A. J. Palmer, S. Pitt, H. Poole, C. Spindloe, P. Thomas, E. Tubman, L. Wilson, W. J. Garbett, G. Gregori, P. Tzeferacos, T. Hodge, A. F. A. Bott

Comments 34 pages, 17 figures, 2 tables

详情
英文摘要

Heat conduction in weakly collisional, magnetised plasma is challenging to model accurately due to multifaceted physics governing heat-carrying electrons, including microinstabilities that scatter electrons and modify heat transport. Capturing these effects requires multidimensional kinetic theory simulations, which are computationally expensive. Experimental constraints overcome this issue, resulting in improved understanding of thermal transport in systems such as the intra-cluster medium of galaxy clusters, and the hot-spot in inertial confinement fusion. In this paper, we present a new experimental platform that produces a weakly collisional high-\b{eta} plasma expected to be susceptible to the whistler heat-flux instability. This platform, to be fielded on the Orion laser, enables characterisation of whistler-regulated thermal conductivity. The platform design is assessed using radiation-magnetohydrodynamics simulations with the code FLASH. Simulations using three thermal conduction models predict conductivity suppression by over an order of magnitude relative to the Spitzer value at whistler saturation, demonstrating the efficacy of the platform.

2602.10038 2026-02-11 physics.optics cond-mat.mes-hall cond-mat.str-el

Nonreciprocal lensing and backscattering suppression via magneto-optical nonlocality

Dmitry Vagin, Maxim A. Gorlach

Comments 6 pages + 10 pages of Supplementary Materials

详情
英文摘要

We introduce a special kind of nonreciprocal electromagnetic response which gives rise to backscattering suppression in the bulk, a long-sought feature in topological photonics, as well as nonreciprocal lensing - an effect when the same structure focuses light incident from one direction and defocuses light propagating in the opposite way. We predict this response in spin spirals and in specially designed metamaterials, validating the key predictions.

2602.10037 2026-02-11 cs.LG cond-mat.stat-mech quant-ph

Effectiveness of Binary Autoencoders for QUBO-Based Optimization Problems

Tetsuro Abe, Masashi Yamashita, Shu Tanaka

Comments 14 pages, 5 figures

详情
英文摘要

In black-box combinatorial optimization, objective evaluations are often expensive, so high quality solutions must be found under a limited budget. Factorization machine with quantum annealing (FMQA) builds a quadratic surrogate model from evaluated samples and optimizes it on an Ising machine. However, FMQA requires binary decision variables, and for nonbinary structures such as integer permutations, the choice of binary encoding strongly affects search efficiency. If the encoding fails to reflect the original neighborhood structure, small Hamming moves may not correspond to meaningful modifications in the original solution space, and constrained problems can yield many infeasible candidates that waste evaluations. Recent work combines FMQA with a binary autoencoder (bAE) that learns a compact binary latent code from feasible solutions, yet the mechanism behind its performance gains is unclear. Using a small traveling salesman problem as an interpretable testbed, we show that the bAE reconstructs feasible tours accurately and, compared with manually designed encodings at similar compression, better aligns tour distances with latent Hamming distances, yields smoother neighborhoods under small bit flips, and produces fewer local optima. These geometric properties explain why bAE+FMQA improves the approximation ratio faster while maintaining feasibility throughout optimization, and they provide guidance for designing latent representations for black-box optimization.

2602.10034 2026-02-11 cond-mat.mtrl-sci

Multiscale Modeling of Metal/Oxide/Metal Conductive Bridging Random Access Memory Cells: from Ab Initio to Finite Element Calculations

Jan Aeschlimann, Fabian Durch, Christoph Weilenmann, Alexandros Emboras, Mathieu Luisier, Juerg Leuthold

详情
英文摘要

We present a multiscale simulation framework to compute the current vs. voltage (I-V ) characteristics of metal/oxide/metal structures building the core of conductive bridging random access memory (CBRAM) cells and to shed light on their resistance switching properties. The approach relies on a finite element model whose input material parameters are extracted either from ab initio or from machine-learned empirical calculations. The applied techniques range from molecular dynamics and nudged elastic band to electronic and thermal quantum transport. Such an approach drastically reduces the number of fitting parameters needed and makes the resulting modeling environment more accurate than traditional ones. The developed computational framework is then applied to the investigation of an Ag/a-SiO2/Pt CBRAM, reproducing experimental data very well. Moreover, the relevance of Joule heating is assessed by considering various cell geometries. It is found that self-heating manifests itself in devices with thin conductive filaments with few-nanometer diameters and at current concentrations in the 10s-microampere range. With the proposed methodology it is now possible to explore the potential of not-yet fabricated memory cells and to reliably optimize their design.

2602.10011 2026-02-11 physics.med-ph q-bio.OT

Towards a topological view of blood pressure regulation

Arturo Tozzi

Comments 9 pages, one figure

详情
英文摘要

Blood pressure regulation is commonly addressed in terms of local mechanisms such as vascular resistance, compliance and neurohumoral control. However, the human vasculature encompasses multiple quasi-closed flow loops under both physiological and pathological conditions. To test whether these loops could influence pressure dynamics beyond local control, we address the role of vascular topology in blood pressure regulation. Using one dimensional flow simulation models, we compared pressure dynamics in open vascular segments and closed vascular loops. We found that in open segments pressure fades away and remains spatially localized, whereas in closed loops pressure can keep circulating around the loop even if resistance in one spot is modified. Since parallel pathways within loops are dynamically coupled rather than independent, pressure changes in one place can affect the entire closed loop, allowing system level pressure patterns to emerge. Also, we assessed the temporal evolution of pressure fluctuations within closed vascular loops in normotensive and hypertensive parameter regimes, before and after loop breaking intervention. This topological approach helps clarifying why drugs or local interventions may fail to lower blood pressure in looped vascular architectures, providing a theoretical interpretation of some forms of resistant hypertension. Because disrupting a loop restores pressure relaxation, it may also help explain the disproportionate pressure changes observed after topology altering events like thrombosis, vascular surgery or embolization of arteriovenous malformations and shunts. Therefore, vascular topology can influence cardiovascular physiology by coupling local pressure flow relations to global constraints on blood pressure regulation, with physiological, pathological and clinical implications.

2602.10010 2026-02-11 cond-mat.supr-con

Magneto-optical study of Nb thin films for superconducting qubits

Amlan Datta, Kamal R. Joshi, Sunil Ghimire, Makariy A. Tanatar, Cameron J. Kopas, Jayss Marshall, Josh Y. Mutus, David P. Pappas, Matthew J. Kramer, Ruslan Prozorov

详情
英文摘要

Among the recognized sources of decoherence in superconducting qubits, the spatial inhomogeneity of the superconducting state and the possible presence of magnetic-flux vortices remain comparatively underexplored. Niobium is commonly used as a structural material in transmon qubits that host Josephson junctions, and excess dissipation anywhere in the transmon can become a bottleneck that limits overall quantum performance. The metal/substrate interfacial layer may simultaneously host pair-breaking loss channels (e.g., two-level systems, TLS) and control thermal transport, thereby affecting dissipation and temperature stability. Here, we use quantitative magneto-optical imaging of the magnetic-flux distribution to characterize the homogeneity of the superconducting state and the critical current density, $j_{c}$, in niobium films fabricated under different sputtering conditions. The imaging reveals distinct flux-penetration regimes, ranging from a nearly ideal Bean critical state to strongly nonuniform thermo-magnetic dendritic avalanches. By fitting the measured magnetic-induction profiles, we extract $j_{c}$ and correlate it with film physical properties and with measured qubit internal quality factors. Our results indicate that the Nb/Si interlayer can be a significant contributor to decoherence and should be considered an important factor that must be optimized.

2602.10008 2026-02-11 cond-mat.str-el

Ground-state phases of $S = 1/2$ Heisenberg models on the body-centered cubic lattice

Rajah P. Nutakki, Filippo Vicentini

Comments 12 pages, 10 figures

详情
英文摘要

Simulating low-temperature properties of three-dimensional frustrated quantum magnets is challenging due to the sign problem and the system sizes required to mitigate substantial finite-size effects. However, there are many experimental examples of three-dimensional crystals that could host exotic low-temperature states of matter, such as quantum spin liquids. We calculate the ground-state phase diagrams of frustrated quantum spin models on the body-centered cubic lattice using neural quantum states. First, we study the antiferromagnetic $J_1-J_2$ model where we find a direct first-order phase transition between Néel and collinear long-range-ordered phases at $(J_2/J_1)_c = 0.705$, consistent with previous studies. Then, in a tetragonally-distorted variant, proposed as a minimal model of NaCa$_2$Cu$_2$(VO$_4$)$_3$, we find no evidence of a quantum paramagnetic ground state, with a first-order phase transition between Néel and chain phases at $(J_{2ab}/J_1)_c = 1.0375$. Therefore, the ground state of the tetragonally-distorted model does not reproduce the low-temperature magnetic properties of NaCa$_2$Cu$_2$(VO$_4$)$_3$, and the inclusion of other effects is necessary to rationalize experimental observations.

2602.09993 2026-02-11 astro-ph.HE

The supernova remnant J0450.4-7050 possesses a jets-shaped point-symmetric morphology

Noam Soker

Comments It will be submitted in two days to allow for comments (including missing references)

详情
英文摘要

By examining recently published images in different wavelengths, I identify a point-symmetric morphology in the Large Magellanic Cloud core-collapse supernova (CCSN) remnant (CCSNR) J0450.4-7050 (SNR 0450-70.9; nicknamed Veliki), which I attribute to at least three pairs of energetic jets that participated in the explosion of the progenitor in the framework of the jittering jets explosion mechanism (JJEM). Two pairs of ears, a pair of blowouts in the north and south along the long axis of this SNR, and a pair of dents compose the point symmetric morphology. The fact that the symmetry axes of two pairs include pairs of opposite structural features in the inner ejecta implies that the shaping is by jets and not due to an interaction with an ambient material. While the JJEM predicts such morphologies, the competing neutrino-driven mechanism cannot account for point-symmetric morphologies. This study provides strong support for the claim that the JJEM is the primary CCSN explosion mechanism.

2602.09984 2026-02-11 quant-ph

Information Theory of Action : Reconstructing Quantum Dynamics from Inference over Action Space

Fabricio Souza Luiz, Marcos César de Oliveira

Comments 29 pages, 1 figure

详情
英文摘要

We develop an information-theoretic reconstruction of quantum dynamics based on inference over action space. The fundamental object is a density of action states encoding the multiplicity of dynamical alternatives between configurations. Maximum-entropy inference introduces a finite resolution scale in action, implying that sufficiently close action contributions are operationally indistinguishable. We show that this indistinguishability, together with probability normalization and action additivity, selects complex amplitudes and unitary evolution as the minimal continuous representation compatible with action additivity, probability normalization, and inference under finite resolution. Quantum interference and unitarity therefore emerge as consequences of these assumptions rather than independent postulates. From the resulting propagator, the Lagrangian, Hilbert-space structure, and Schrödinger equation follow as derived consequences. In the infinitesimal-time limit, action differences universally fall below the resolution scale, making coherent summation the minimal consistent description at every step. The numerical value of the action scale is fixed empirically and identified with $\hbar$.

2602.09977 2026-02-11 hep-th gr-qc

Split Representations and Bubble Resummation for Massive de Sitter Correlators

Jonathan Gräfe, Ivo Sachs

Comments 46 pages, 13 figures

详情
英文摘要

We combine spectral- and split representations to factorize multi-loop momentum space diagrams, in the Schwinger-Keldysh formulation for cosmological correlators, with massive scalars in the loop. This allows us to extend the resummation of loop contributions from flat to de Sitter space. Furthermore, in our split representation the signal part of the correlators can be identified directly on the integrand level from the spectral function. We apply this to describe the non-perturbative flow of the EFT background and the cosmological collider signals in a large-N model.

2602.09975 2026-02-11 cond-mat.mtrl-sci cond-mat.supr-con

Relativistic Effects in LaBi$_2$ Thin Films

Reiley Dorrian, Sungmin Song, Jinwoong Kim, Mizuki Ohno, Seung-Hoon Jhi, Nicholas Kioussis, Joseph Falson

详情
英文摘要

Chemical substitution in crystalline quantum materials is a powerful way to explore the consequences of strong spin-orbit coupling on their structural and electronic properties. In this work, we present an investigation of thin films of the La$\textit{Pn}_2$ ($\textit{Pn}$~=~Sb, Bi) class of layered square-net intermetallics. We report the growth of LaBi$_2$ with a pristine layer-by-layer growth mode, classifying it as a good metal displaying superconductivity at $\sim$0.55~K. Compared to LaSb$_2$, we attribute the enhanced metallic behavior and improved growth dynamics of LaBi$_2$ to significant relativistic corrections to its electronic band structure and the resulting impact on both surface energy and intrinsic phonon scattering.

2602.09962 2026-02-11 hep-ph

Cosmological signature and light Dark Matter in Dirac $L_μ-L_τ$ model

Pritam Das

Comments 27 pages with 9 figures

详情
英文摘要

We revisit an anomaly-free extension of the Standard Model (SM) $viz.$ gauged ${L_μ-L_τ}$ model in the Dirac framework, where the local $U(1)_{L_μ-L_τ}$ symmetry breaks and gives rise to a new gauge boson $Z'$ and corresponding gauge coupling $g_{μτ}$. Three additional heavy vector-like fermions, three light right-handed neutrinos and two heavy singlet scalars are added to complete the model framework for Dirac neutrinos. Another singlet vector-like fermion is added with a new gauge charge, which serves as a viable DM candidate, and the correct relic abundance is obtained via the resonance effect. The parameter space is considered after satisfying the current bounds on $M_{Z'}$ and the gauge coupling $g_{μτ}$. The influence of dark radiations coming from the additional light degrees of freedoms are studied in connection with the dark matter. After imposing all relevant theoretical and experimental constraints, the allowed parameter space is found to be highly restricted yet still accessible to ongoing and near-future experiments, rendering the scenario strongly predictive. Moreover, clear correlations among the relevant observables emerge throughout this study, making the model testable in current and future experimental searches.

2602.09956 2026-02-11 hep-ph cs.NA hep-th math-ph math.MP math.NA

Elliptic Multiple Polylogarithms with Arbitrary Arguments in \textsc{GiNaC}

Claude Duhr, Florian Lorkowski, Robin Marzucca, Sofia Mauc, Stefan Weinzierl

Comments 29 pages, 3 figures, discussed code to be released in GiNaC

详情
英文摘要

We present an algorithm for the numerical evaluation of elliptic multiple polylogarithms for arbitrary arguments and to arbitrary precision. The cornerstone of our approach is a procedure to obtain a convergent $q$-series representation of elliptic multiple polylogarithms. Its coefficients are expressed in terms of ordinary multiple polylogarithms, which can be evaluated efficiently using existing libraries. In a series of preparation steps the elliptic polylogarithms are mapped into a region where the $q$-series converges rapidly. We also present an implementation of our algorithm into the \texttt{GiNaC} framework. This release constitutes the first public package capable of evaluating elliptic multiple polylogarithms to high precision and for arbitrary values of the arguments.

2602.09954 2026-02-11 astro-ph.GA

Physical properties of circumnuclear ionising clusters. IV. NGC 1097

Sandra Zamora, Angeles I. Díaz, Asier Castrillo

Comments 14 pages, 10 figures, Submitted to Astronomy & Astrophysics

详情
英文摘要

The circumnuclear star-forming ring of the barred spiral galaxy NGC 1097 provides a unique laboratory to study star formation under extreme conditions. This work aims to derive the physical properties of the circumnuclear star-forming regions (CNSFRs) using MUSE integral field spectroscopy observations. A total of 24 individual ionised HII are identified and analysed within its ring, which spans from $\sim$385 pc to $\sim$1.3 kpc. Despite the complex nuclear activity, all HII regions are found to be purely photoionised. Directly derived abundances reveal supersolar metallicities, with the highest one exceeding five times the solar value (12+log(S/H) = 7.875 $\pm$ 0.353, T$_e$([SIII]) = 3912 $\pm$ 567 K), and representing the highest abundance reported to date. In this high-metallicity regime, we find a break in the ionisation parameter-[SII]/[SIII] relation, which can be explained by changes in the ionisation structure and line emissivities, as confirmed by photoionisation models that successfully reproduce the observed emission-line ratios. Our results also indicate that the local gas supply regulates the star formation activity within the ring, with the young stars ionising 8 % of the total gas in the ring. Furthermore, our findings support a propagating starburst scenario, originating in the galaxy nucleus and extending towards the ends of the bar and into the circumnuclear ring through bar-driven shocks, this being consistent with the results of previous multi-wavelength studies. Finally, we likely detect optical signatures associated with one of the two known jets in this galaxy. This finding, together with the radio core emission previously found at sub-parsec scales, reflects the presence of feedback processes operating even on small galactic disc scales.