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2605.31112 2026-06-01 cond-mat.quant-gas cond-mat.stat-mech nucl-th

Functional methods for quantum thermodynamics

量子热力学的泛函方法

Sibo Wang, Samuel Degen, Haozhao Liang

AI总结 本文通过基准测试泛函重整化群密度泛函理论(FRG-DFT)在单点Bose-Hubbard模型中的精确热力学,验证了从微观哈密顿量构建密度泛函的非微扰方法,并提出了避免虚假自相互作用的两个一般性要求。

Comments 24 pages, 14 figures; comments are welcome

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AI中文摘要

泛函重整化群提供了一种从微观哈密顿量构建量子多体系统密度泛函的非微扰且可系统改进的途径。在此,我们通过将泛函重整化群密度泛函理论(FRG-DFT)与单点Bose-Hubbard模型的精确热力学进行基准测试,推进了这一程序。该模型是一个理想的测试平台,因为它可解析求解,但在虚时相干态路径积分中仍存在微妙之处,其中朴素的连续处理会产生虚假的自相互作用。我们证明,仔细的Hubbard-Stratonovich推导识别出必须包含在FRG-DFT流中的自相互作用修正项,以恢复精确热力学。然后,我们在密度、温度和相互作用强度的广泛范围内,系统比较了自由能、化学势和连接密度关联函数所得流方程层次结构的几种闭合方式。基准测试表明,自由能相对稳健,而化学势和涨落可观测量提供了层次闭合更敏锐的诊断。最大熵闭合给出了最准确的总体描述,甚至再现了低温下连接双密度关联函数的振荡结构。这些结果确定了量子热力学泛函方法的两个一般性要求:重整化群流方程必须保留等时接触减法以避免虚假自相互作用,并且层次结构的任何闭合都必须保持密度关联函数的统计一致性。这项工作为跨凝聚态物理、超冷原子物理、核物理以及量子化学领域,从第一性原理推导量子多体系统的密度泛函提供了可控基础。

英文摘要

The functional renormalization group provides a nonperturbative and systematically improvable route to constructing density functionals for quantum many-body systems from microscopic Hamiltonians. Here we advance this program by benchmarking functional-renormalization-group density functional theory (FRG-DFT) against the exact thermodynamics of the single-site Bose-Hubbard model. This model provides an ideal testing ground because it is analytically solvable, yet remains subtle in the imaginary-time coherent-state path integral, where a naive continuum treatment generates a spurious self-interaction. We show that a careful Hubbard-Stratonovich derivation identifies the self-interaction correction term that must be included in the FRG-DFT flow to recover the exact thermodynamics. We then systematically compare several closures of the resulting hierarchy of flow equations for the free energy, chemical potential, and connected density correlators over broad ranges of density, temperature, and interaction strength. The benchmark shows that the free energy is comparatively robust, whereas the chemical potential and fluctuation observables provide much sharper diagnostics of the hierarchy closure. A maximum-entropy closure gives the most accurate overall description and reproduces even the low-temperature oscillatory structure of the connected two-density correlator. These results identify two general requirements for functional approaches to quantum thermodynamics: the renormalization group flow equation must retain the equal-time contact subtraction to avoid spurious self-interactions, and any closure of the hierarchy must preserve the statistical consistency of density correlators. This work provides a controlled foundation for deriving ab initio density functionals for quantum many-body systems across condensed-matter, ultracold-atom, and nuclear physics, as well as quantum chemistry.

2605.31109 2026-06-01 physics.space-ph math-ph math.MP

An extended scattering kernel formalism for multi-scale gas-surface dynamics

多尺度气体-表面动力学的扩展散射核形式

Sabin-Viorel Anton, Bernardo Sousa Alves, Christian Siemes, Jose van den IJssel, Pieter N. A. M. Visser

AI总结 提出一种基于粗糙度的扩展散射核形式,通过单反射和多反射算子将局部核提升至更大尺度,并证明全局核保持互易性、归一化和非负性,为粗糙表面气体散射建模提供通用框架。

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AI中文摘要

气体粒子与非吸收表面的相互作用通常使用散射核形式来描述。在该框架中,算子 $\mathbf{K}$ 将入射速度分布映射到反射速度分布。该算子是自伴的,并且在由三维麦克斯韦-玻尔兹曼分布加权的 $L^2$ 空间中具有范数 $\lVert \mathbf{K} \rVert = 1$,且必须满足非负性、归一化和互易性。在标准形式中,$\mathbf{K}$ 通过单个算子表示所有气体-表面相互作用机制的总效应,而不区分这些机制发生的物理尺度。然而,对于粗糙表面的气体散射,将不同粗糙度尺度相关的几何效应与原子尺度上发生的潜在热化学过程分离是有利的。因此,我们引入了散射核形式的基于粗糙度的扩展,其中通过统计定义的表面形态相关的单反射和多反射算子将局部核连续提升至更大尺度。我们推导了充分条件,使得当这些性质对于最小尺度核成立时,所得的全局核保持互易性、归一化和非负性。我们进一步表明,这些构造定义了散射核空间上的算子,并建立了相关的多尺度组合律,允许独立的粗糙度贡献递归组合。由此产生的框架为任意尺度分解的粗糙表面气体散射建模提供了通用基础。

英文摘要

Gas-particle interactions with non-absorbing surfaces are commonly described using the scattering-kernel formalism. In this framework, an operator $\mathbf{K}$ maps incident velocity distributions to reflected velocity distributions. The operator is self-adjoint and has norm $\lVert \mathbf{K} \rVert = 1$ in an $L^2$ space weighted by the three-dimensional Maxwell-Boltzmann distribution, and must satisfy non-negativity, normalisation, and reciprocity. In standard formulations, $\mathbf{K}$ represents the aggregate effect of all gas-surface interaction mechanisms through a single operator, without distinguishing the physical scales at which these mechanisms occur. For gas scattering from a rough surface, however, it is advantageous to separate geometric effects associated with distinct roughness scales from the underlying thermochemical processes occurring at the atomic scale. We therefore introduce a roughness-based extension of the scattering-kernel formalism, in which a local kernel is successively lifted to larger scales via single- and multi-reflection operators associated with statistically defined surface morphologies. We derive sufficient conditions under which the resulting global kernels preserve reciprocity, normalisation, and non-negativity whenever these properties hold for the smallest-scale kernel. We further show that these constructions define operators on the space of scattering kernels, and establish the associated multi-scale composition laws that allow independent roughness contributions to be combined recursively. The resulting framework provides a general basis for modelling gas-surface scattering on rough surfaces with arbitrary scale decompositions.

2605.31107 2026-06-01 cond-mat.mtrl-sci physics.data-an

Clustering in atom probe tomography data: coordination number metric, percolation-based parameter scaling, and size effects

原子探针断层扫描数据中的聚类:配位数度量、基于逾渗的参数缩放和尺寸效应

Mykola Lazarev, John Banhart

AI总结 提出基于成分的配位数度量用于高阶聚类,通过逾渗阈值缩放定义自相似变量,实现聚类方法间参数迁移,并利用模拟验证该方法优于传统溶质密度方法。

Comments 41 pages, 17 figures

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AI中文摘要

在原子探针断层扫描(APT)中识别新相纳米级形核的能力通常受到聚类算法对用户定义控制参数的敏感性的限制。传统方法通常依赖欧几里得距离度量且仅考虑溶质原子,从而丢弃了包含大部分空间信息的溶剂原子。这里,我们引入一种基于成分的配位数度量,并将其应用于高阶聚类。使用各种度量,我们研究了典型APT结构中的逾渗现象。通过将聚类属性缩放到相应的逾渗阈值,我们定义了一个自相似变量,该变量几乎对度量、聚类参数和结构无序不变。该变量提供了聚类的相关描述,并实现了聚类方法之间最优参数的形式化迁移。我们还研究了小析出物中的特征聚类行为,并量化了析出物-基体界面如何改变成分谱并展宽聚类曲线。最后,通过结合有限空间分辨率、检测效率和其他APT重建伪影的模拟,我们表明基于配位数的方法有效补偿了非均匀膨胀,并在所有测试场景中优于基于溶质密度的方法。

英文摘要

The ability to identify nanometer-scale nuclei of new phases in atom probe tomography (APT) is often limited by the sensitivity of clustering algorithms to user-defined control parameters. Conventional approaches typically rely on the Euclidean distance metric and consider only solute atoms, thereby discarding the solvent atoms that contain most of the spatial information. Here, we introduce a coordination-number metric based on the composition and apply it to higher-order clustering. Using various metrics, we investigate percolation in typical APT structures. By scaling clustering properties to the corresponding percolation thresholds, we define a self-similar variable that is almost invariant with respect to metrics, clustering parameters, and structural disorder. This variable provides a relevant description of clustering and enables the formal transfer of optimal parameters between clustering methods. We also study the characteristic clustering behavior in small precipitates and quantify how the precipitate-matrix interface alters the composition spectrum and broadens the clustering curve. Finally, using simulations that incorporate finite spatial resolution, detection efficiency, and other APT reconstruction artifacts, we show that the approach based on coordination numbers effectively compensates for heterogeneous dilations and outperforms solute-density-based methods in all tested scenarios.

2605.31104 2026-06-01 cs.HC

Extending the UXR Point of View Playbook: Triangulating Insights in Complex Developer Domains

扩展UXR观点剧本:在复杂开发者领域中的三角验证洞察

Sarah Kianfar

AI总结 本文通过云开发者工具的多方法研究,提出扩展UXR观点剧本,引入三张新卡片(范式转变、可解释性即信任、摩擦成本),以三角验证定性和定量数据,形成高置信度观点。

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AI中文摘要

随着用户体验研究(UXR)的成熟,从业者面临着从数据收集转向建立具有战略影响力的引人注目的观点(POV)的挑战。本文提出了对UXR POV剧本的扩展,特别关注从“洞察生成”层到“POV”层的过渡。基于在云开发者工具(涵盖AI代理、命令行界面(CLI)和错误消息)中进行的广泛多方法研究,我们展示了如何通过三角验证定性和定量数据来促进高置信度POV的创建。我们引入了从这项研究中得出的三张新“剧本卡”:范式转变、可解释性即信任以及摩擦成本。这些卡片为研究人员提供了一种结构化机制,将复杂的技术发现转化为无可辩驳的商业叙事。

英文摘要

As User Experience Research (UXR) matures, practitioners face the challenge of moving beyond data collection toward establishing a compelling Point of View (POV) that drives strategic impact. This paper proposes an extension to the UXR POV Playbook, specifically focusing on the transition from the "Insight Generation" layer to the "POV" layer. Drawing on extensive multi-method research in Cloud Developer Tools, spanning AI Agents, Command Line Interfaces (CLI), and Error Messages, we demonstrate how triangulating qualitative and quantitative data facilitates the creation of high-confidence POVs. We introduce three new "Playbook Cards" derived from this research: The Paradigm Shift, Explainability as Trust, and The Cost of Friction. These cards provide a structured mechanism for researchers to translate complex technical findings into irrefutable business narratives.

2605.31103 2026-06-01 physics.data-an hep-ex stat.ML

Model-Agnostic Signal Discovery with Machine Learning: Bridging the Gap Between Theory and Practice

基于机器学习的模型无关信号发现:弥合理论与实践的鸿沟

Oz Amram, Marco Letizia, Mikael Kuusela

AI总结 本文综述了基于AI的模型无关搜索策略,旨在通过广泛探索而非特定假设来增强实验的发现潜力,并讨论了验证与解释方法。

Comments 37 pages, 7 figures. Part of the VERaiPHY initiative

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AI中文摘要

复杂科学数据中新现象的搜索主要是模型依赖的,针对特定假设进行优化,因此覆盖可能信号空间的能力有限。最近,基于AI的模型无关搜索策略(其中许多在高能物理中首创)被提出,提供了一种互补范式,优先考虑广泛探索而非定制分析。这些技术提供了增强现代实验整体发现潜力的机会,特别是在理论指导稀缺的领域。在本文中,我们回顾了基于AI的模型无关策略主要类别的概念框架。我们讨论了这些方法的潜在陷阱,以及验证和解释的策略。我们希望本文能为从业者和有兴趣了解更多关于这些模型无关搜索策略的研究人员提供有用的参考。

英文摘要

Searches for new phenomena in complex scientific data are predominantly model-dependent, optimized for specific hypotheses, and therefore limited in their coverage of the space of possible signals. Recently, new AI-based model-agnostic search strategies, many of which have been pioneered in high-energy physics, have been proposed which provide a complementary paradigm, prioritizing broad exploration over tailored analyses. These techniques offer an opportunity to enhance the overall discovery potential of modern experiments, especially in regimes where theoretical guidance is scarce. In this document, we review the conceptual framework behind the main classes of AI-based model-agnostic strategies. We discuss the potential pitfalls of these methods, and strategies for their validation and interpretation. We aim for this document to serve as a useful reference both for practitioners and for researchers interested in learning more about these model-agnostic search strategies.

2605.31102 2026-06-01 physics.optics

Rewritable Chirality of Metasurfaces with Permittivity-Asymmetric Flatband Quasi-Bound States in the Continuum

具有介电常数不对称连续谱平准束缚态的超表面可重写手性

Tao Jiang, Haiyang Hu, Dmytro Gryb, Leonardo de S. Menezes, Maxim V. Gorkunov, Alexander A. Antonov, Andreas Tittl

AI总结 通过选择性涂覆PMMA在硅双纳米棒单元上实现可重写的圆偏振平带态,并展示基于空间选择性涂覆的手性编码。

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AI中文摘要

平带本征态广泛应用于超光子学中增强角度鲁棒的光-物质相互作用。然而,控制平带的偏振仍然具有挑战性,因为一旦超表面制造完成,偏振通常是固定的,无法进行后期修改。在这里,我们提出了一种可重写的介电常数不对称连续谱准束缚态(ε-qBIC)超表面平台,其中对硅双纳米棒单元进行选择性聚甲基丙烯酸甲酯(PMMA)涂层,建立了一个圆偏振平带态。通过改变PMMA厚度,该态的偏振可以进一步控制在从右旋圆偏振到线偏振再到左旋椭圆偏振的范围内。平带在入射角高达10度时保持稳定的共振位置和鲁棒的远场偏振。重要的是,PMMA层可以在同一纳米结构上被去除、重新涂覆和重新图案化,从而提供重写光学响应的途径。基于这一能力,我们通过空间选择性PMMA涂层实验演示了手性编码。这些结果为实现具有可重写手性的高品质因子平带超表面提供了一种实用策略,从而为手性编码和手性光子器件等应用开辟了机会。

英文摘要

Flatband eigenstates are widely applied to enhance angle-robust light-matter interactions in metaphotonics. However, controlling the polarization of flatbands remains challenging, as it is usually fixed once the metasurface is fabricated, with no options of post-fabrication modification. Here, we present a rewritable permittivity-asymmetric quasi-bound state in the continuum (ε-qBIC) metasurface platform, where selective polymethyl methacrylate (PMMA) coating of a silicon double-nanorod unit cell establishes a circularly polarized flatband state. By varying the PMMA thickness, the polarization of this state can be further controlled in the range from the right-circular to linear and to left-elliptical. The flatbands maintain stable resonance positions and robust far-field polarizations for the incidence angles up to 10 degrees. Importantly, the PMMA layer can be removed, recoated, and re-patterned on the same nanostructure, providing a pathway to rewrite the optical response. Building on this capability, we experimentally demonstrate the chirality encoding by spatially selective PMMA coating. The results establish a practical strategy for realizing high quality factor flatband metasurfaces with rewritable chirality, thus opening opportunities for applications in chiral encoding and chiroptical photonic devices in general.

2605.31101 2026-06-01 eess.AS

On the Use of Dereverberation for Acoustic Feedback Cancellation

论去混响在声学反馈消除中的应用

Basil Liekens, Arnout Roebben, Toon van Waterschoot, Marc Moonen

AI总结 本文证明在温和条件下,声学反馈信号可视为源信号的混响版本,从而将联合去混响和声学反馈消除问题简化为纯去混响问题,并通过仿真验证。

Comments Accepted for publication in proceedings of EUSIPCO 2026

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AI中文摘要

在公共广播系统和助听器中,最大可实现的放大或增益受到声学反馈的限制。因此,为了能够应用更高的增益,需要反馈消除方法。此外,通常还希望在播放前对记录信号进行去混响,即去除信号的晚期混响分量。本文证明,在两个温和条件下,声学反馈信号可以写为源信号的混响版本。因此,可以将联合去混响和声学反馈消除问题视为纯去混响问题,这意味着去混响算法可以应用于联合问题。仿真证实了这一发现。

英文摘要

In public address systems and hearing aids, the maximally achievable amplification or gain is limited by acoustic feedback. Therefore, in order to be able to apply a higher gain, feedback cancellation methods are required. In addition, it is oftentimes also desirable to dereverberate a recorded signal, that is, remove the late reverberation component of the signal, before playing it back. In this paper, it is shown that under two mild conditions, the acoustic feedback signal can be written as a reverberant version of the source signal. Therefore, it is possible to treat the joint dereverberation and acoustic feedback cancellation problem as a dereverberation-only problem, meaning that dereverberation algorithms can be applied to the joint problem. Simulations corroborate this finding

2605.31098 2026-06-01 cs.CG

How Many Slopes Does Polynomial Area Cost?

多项式面积代价需要多少斜率?

Michael A. Bekos, Eleni Katsanou, Philipp Kindermann, Maria Eleni Pavlidi

AI总结 研究有界度图平面绘图中斜率数量、每边弯曲数与面积需求之间的权衡,提出新构造以多项式面积实现少量弯曲,同时略微增加斜率数量。

Comments A preliminary version of this work was published at SWAT 2026

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AI中文摘要

在这项工作中,我们研究了有界度图的平面绘图中斜率数量、每边弯曲数与面积需求之间的相互作用。我们的动机源于:虽然许多算法在多项式面积内为较小度数的图生成具有少量斜率的平面图,但现有针对更高度数图的方法通常需要超多项式面积。我们通过提出新的构造来填补文献中的这一空白,这些构造在多项式面积内实现每边少量弯曲,同时略微增加所需斜率数量,从而首次系统研究了斜率、弯曲和面积之间的权衡。

英文摘要

In this work, we study the interplay between the number of slopes, the number of bends per edge, and the area requirements for planar drawings of bounded-degree graphs. Our motivation stems from the fact that, while numerous algorithms produce planar drawings with few slopes for graphs of relatively small degree in polynomial area, existing approaches for higher-degree graphs often require super-polynomial area. We address this gap in the literature by presenting new constructions that yield polynomial-area drawings with few bends per edge while slightly increasing the required number of slopes, thereby providing the first systematic study of slopes, bends and area trade-offs.

2605.31092 2026-06-01 cs.ET

Accelerating NBTI Aging Evaluation via Physics-Aware Graph Attention Networks

通过物理感知图注意力网络加速NBTI老化评估

RenJie Zheng, HengXi Liu, ShuJun Gao, Cong Li

AI总结 提出基于物理感知图注意力网络的老化评估框架,通过将非结构化器件网格映射为属性图并引入双端归一化与对数尺度损失优化,实现高精度快速NBTI老化预测,加速比达17000倍。

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AI中文摘要

随着半导体技术向更小节点推进,长时间工作负载下的负偏置温度不稳定性(NBTI)已成为制约可靠性感知设计-技术协同优化(DTCO)的重要瓶颈。传统的TCAD模拟在评估器件老化特性时计算开销巨大,难以满足高效迭代设计周期的需求。为解决这一挑战,本文提出了一种基于物理感知图注意力网络(Physics-Aware RelGAT)的老化评估框架。通过将非结构化器件网格无损映射为属性图,该框架构建了45维器件编码方案,融合了界面陷阱分布和宏观电热应力,实现了从底层物理量到器件退化特性的直接映射。为克服跨数量级电流预测的挑战,引入了双端归一化策略和对数尺度损失函数优化,确保模型具备高精度拟合能力。实验结果表明,该模型在独立测试集上的平均误差仅为1.27%,相比传统TCAD模拟实现了约17000倍的加速。该框架为先进工艺节点下的电路可靠性评估提供了一种兼顾物理保真度与工业级效率的解决方案。

英文摘要

As semiconductor technology advances to smaller nodes, Negative Bias Temperature Instability (NBTI) under prolonged workloads has emerged as a significant bottleneck constraining reliability-aware Design-Technology Co-Optimization (DTCO). Conventional TCAD simulations incur prohibitive computational overhead when evaluating device aging characteristics, making it difficult to satisfy the demand for efficient iterative design cycles. To address this challenge, this paper proposes an aging evaluation framework based on a physics-aware graph attention network (Physics-Aware RelGAT). By losslessly mapping unstructured device meshes into attributed graphs, this framework constructs a 45-dimensional device encoding scheme that integrates interface trap distributions and macroscopic electro-thermal stresses, achieving a direct mapping from underlying physical quantities to device degradation characteristics. To overcome the challenge of predicting currents that span multiple orders of magnitude, a dual-end normalization strategy and a log-scale loss function optimization are introduced, ensuring the model possesses high-precision fitting capabilities. Experimental results demonstrate that the model achieves a mean error of only 1.27% on an independent test set, achieving an acceleration of approximately 17,000 times compared to traditional TCAD simulations. This framework provides a solution for the assessment of circuit reliability in advanced process nodes that successfully balances physical fidelity with industrial-grade efficiency.

2605.31091 2026-06-01 astro-ph.EP astro-ph.SR

Metamorphoses of carbon and oxygen in protoplanetary discs: how chemistry and radial drift transform inner disc C/O ratios

原行星盘中碳和氧的蜕变:化学与径向漂移如何改变内盘C/O比

Tamara Molyarova, Richard A. Booth, Catherine Walsh

AI总结 本研究通过化学模型探讨了宇宙射线驱动的冰解离和尘埃径向漂移如何影响原行星盘内盘的C/O比,发现甲烷消耗和尘埃陷阱共同导致内盘C/O比降低。

Comments 21 pages, 9 figures, accepted to MNRAS

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AI中文摘要

原行星盘的化学成分对其热结构和尘埃性质敏感,并能提供盘演化的见解。詹姆斯·韦伯空间望远镜(JWST)的最新观测揭示了内盘成分与盘大小、吸积率和恒星质量的相关性,这可以通过尘埃径向漂移在重新分布原始挥发物中的关键作用来解释。我们探索了化学反应如何改变随卵石携带的冰的成分,以及它们如何影响太阳质量恒星周围盘的内盘C/O比。我们考虑了由尘埃碎裂速度设定的不同漂移效率,并包括不同位置的尘埃陷阱。我们改变了入射宇宙射线电离率$ζ$和宇宙射线解离冰的效率,并考虑了碳粒破坏的影响。我们发现,在$<1$ Myr内甲烷的消耗阻止了富碳气体向内盘的输送,并在$ζ\geq10^{-17}$ s$^{-1}$时产生$\mathrm{C/O} \lesssim1$。尘埃陷阱收集了通过甲烷破坏形成的水和富碳冰,进一步降低了内盘的金属丰度和C/O比。宇宙射线驱动的冰光解离可以将水转化为O$_2$,将含碳分子转化为CO,如果解离产物中$\gtrsim10\%$能够参与表面反应,则允许冰逃逸陷阱。我们讨论了观测意义,并得出结论:宇宙射线及其对冰的影响是决定化学对内盘成分影响的关键因素。

英文摘要

The chemical composition of a protoplanetary disc is sensitive to its thermal structure and dust properties, and can provide insights into the disc evolution. Recent observations with the James Webb Space Telescope (JWST) reveal correlations of the inner disc compositions with disc size, accretion rate and stellar mass, explained by the key role of dust radial drift in redistributing primordial volatiles. We explore how chemical reactions change the composition of ices carried with pebbles and how they affect the inner disc C/O ratios in a disc around a solar mass star. We consider different drift efficiencies set by dust fragmentation velocity and include dust traps at different locations. We vary the incident cosmic ray ionisation rate $ζ$ and the efficiency of cosmic ray dissociation of ices, and consider the effect of carbon grain destruction. We find that methane depletion within $<1$ Myr prevents the delivery of carbon-rich gas to the inner disc and yields $\mathrm{C/O} \lesssim1$ for $ζ\geq10^{-17}$ s$^{-1}$. Dust traps collect water and carbon-rich ices formed via methane destruction, further lowering the inner disc metallicity and C/O ratio. Cosmic-ray driven photodissociation of ices can convert water to O$_2$ and carbon-bearing molecules to CO, allowing ices to escape the trap if $\gtrsim10 \%$ of the dissociated products can participate in surface reactions. We discuss the observational implications and conclude that cosmic rays and their effect on ices are the key factors that determine the impact of chemistry on the inner disc composition.

2605.31089 2026-06-01 astro-ph.HE

Extreme Transients in Gamma Rays

伽马射线中的极端瞬变现象

Daniela Hadasch, Dmitriy Khangulyan

AI总结 本文综述了能量高于100 MeV的极端伽马射线瞬变现象,包括伽马射线暴、新星、喷流快速变化以及蟹状星云耀发等,重点讨论了粒子加速、辐射机制和观测特征。

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Journal ref
New Astronomy Reviews, Volume 102, id.101749, June 2026
AI中文摘要

极端伽马射线瞬变代表了高能天体物理学中一些最具能量和物理约束的现象。它们的特征是快速、大幅度的变化,以及接近粒子加速、冷却和致密性基本极限的物理条件。在这篇综述中,我们关注探测到的大约100 MeV以上的瞬变,并将极端事件定义为那些涉及天体系统灾难性转变(如恒星爆炸、致密天体合并和潮汐瓦解事件)或表现出粒子加速在极端状态下运行的证据的事件。这些系统由引力能、磁能、核能或动能的快速释放驱动,激波和磁重联在产生超相对论性粒子群和非热辐射中起核心作用。我们总结了约束发射区大小、磁化强度和洛伦兹因子的观测和理论诊断,包括变化时标、光度-时标相关性以及MeV-TeV能段的光谱演化。我们还回顾了空间伽马射线仪器、地面切伦科夫和空气簇射天文台在探测短时高能爆发方面的互补能力。讨论的极端瞬变类别包括伽马射线暴、新星、来自河外和银河喷流的快速变化辐射。此外,由于其极端性质,我们还包括了从蟹状星云探测到的耀发辐射。虽然每种类型的耀发对这些源的现象学和理论提出了有趣的挑战,但总体而言,这些事件构成了极端伽马射线变化的图景。

英文摘要

Extreme gamma-ray transients represent some of the most energetic and physically constraining phenomena in high-energy astrophysics. They are characterized by rapid, large-amplitude variability and by physical conditions approaching fundamental limits on particle acceleration, cooling, and compactness. In this review, we focus on transients detected above around 100 MeV and define extreme events as either those involving catastrophic transformations of astrophysical systems (such as stellar explosions, compact-object mergers, and tidal-disruption events) or those exhibiting evidence for particle acceleration operating in an extreme regime. These systems are powered by the rapid release of gravitational, magnetic, nuclear, or kinetic energy, with shocks and magnetic reconnection playing a central role in producing ultra-relativistic particle populations and non-thermal radiation. We summarize observational and theoretical diagnostics that constrain the size, magnetization, and Lorentz factor of the emitting region, including variability timescales, luminosity-timescale correlations, and spectral evolution across the MeV-TeV domain. We further review the complementary capabilities of space-borne gamma-ray instruments, ground-based Cherenkov and air-shower observatories in detecting short-lived, high-energy outbursts. Extreme transient classes discussed include gamma-ray bursts, novae, rapidly variable emission from extragalactic and Galactic jets. Also, because of its extreme aspects, we include flaring emission detected from the Crab Nebula. While each type of these flares poses interesting challenges for phenomenology and theory of these sources, together, these events form the landscape of extreme gamma-ray variability.

2605.31088 2026-06-01 math.PR stat.CO stat.ML

On couplings for kinetic Langevin diffusions

关于动能朗之万扩散的耦合

Nawaf Bou-Rabee, Sonja Cox, Roy Schieven

AI总结 研究动能朗之万扩散及其分裂离散化中耦合与全变差界的关系,通过非马尔可夫耦合实现精确收缩并改进现有结果。

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AI中文摘要

对于动能朗之万扩散及其分裂离散化,次椭圆噪声结构使得耦合与全变差(TV)界之间的关系比椭圆情况更微妙。我们证明,对于具有二次势能的动能朗之万方程,没有马尔可夫耦合(连续或离散)能够捕捉两个不同初始值解之间TV距离的渐近衰减率;经典的迭代一次射击(或粘性)耦合(我们为其推导了精确的收缩公式)饱和了这个下界。在建设性方面,我们展示了Chak和Monmarché最近获得的尖锐TV界可以通过一个显式的非马尔可夫耦合得到自然解释,该耦合基于由经典最小能量控制问题表征的最优合并轨迹。对于OBABO分裂方案,该方法还消除了Chak和Monmarché工作中的Hessian-Lipschitz、步长和最终时间假设。

英文摘要

For the kinetic Langevin diffusion and its splitting discretizations, the hypoelliptic noise structure makes the relationship between couplings and total variation (TV) bounds more subtle than in the elliptic case. We establish that, for the kinetic Langevin equation with quadratic potential, no Markovian coupling (continuous or discrete) captures the asymptotic decay rate of the TV distance between two solutions with different initial values; the canonical iterated one-shot (or sticky) coupling, for which we derive an exact contraction formula, saturates this lower bound. On the constructive side, we show that the recent sharp TV bounds obtained by Chak and Monmarché admit a natural interpretation through an explicit non-Markovian coupling, built from an optimal coalescence trajectory characterized by a classical minimum-energy control problem. For the OBABO splitting scheme, this approach additionally eliminates the Hessian-Lipschitz, step-size, and final-time assumptions in the work of Chak and Monmarché.

2605.31087 2026-06-01 physics.optics

Mach-Zehnder based Rotational Shearing Interferometer for Non-destructive Testing using Spatial Phase-Shifting Shearography

基于马赫-曾德旋转剪切干涉仪的非破坏性检测:使用空间相移剪切散斑干涉术

Valentin-Johannes Bastgen, Michael Schuth, Georg von Freymann

AI总结 提出一种基于马赫-曾德干涉仪的新型光学装置,通过空间相移剪切散斑干涉术结合旋转剪切,实现快速非破坏性检测,对切向位移梯度敏感,适用于工业环境。

Comments 12 pages, 8 figures

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AI中文摘要

本工作介绍了一种基于马赫-曾德干涉仪的新型光学装置,实现了具有旋转剪切的空间相移剪切散斑干涉术。该光学概念采用虚拟双缝配置,将剪切量的调整与空间载波频率的产生解耦,从而能够灵活控制测量灵敏度。通过使用道威棱镜进行图像旋转,在光学装置内产生旋转剪切。由于所提出的系统基于空间相移剪切散斑干涉术,可以在相机帧率下进行全场测量,使得该方法适用于工业条件下的快速非破坏性检测。与传统的线性剪切配置相比,旋转剪切方法对围绕旋转中心的切向位移梯度敏感。本文将所提出的旋转剪切方法与线性剪切配置进行了比较,结果表明能够可靠地检测相关缺陷。空间相移剪切散斑干涉术与旋转剪切相结合,为工业非破坏性检测应用提供了巨大潜力,特别是在密封技术和旋转对称部件的检测方面。

英文摘要

This work introduces a novel optical setup based on a Mach-Zehnder interferometer, enabling spatial phase shifting shearography with rotational shear. The optical concept employs a virtual double slit configuration, which decouples the adjustment of the shear amount from the generation of the spatial carrier frequency, thereby enabling flexible control of the measurement sensitivity. Rotational shear is generated within the optical setup by means of image rotation using Dove prisms. Since the proposed system is based on spatial phase shifting shearography, full field measurements can be performed at the camera frame rate, making the method suitable for fast non destructive testing under industrial conditions. In contrast to conventional linear shear configurations, the rotational shear approach is sensitive to tangential displacement gradients around the centre of rotation. In this paper, the proposed rotational shear approach is compared with linear shear configurations, with the results demonstrating reliable detection of relevant defects. Spatial phase shifting shearography combined with rotational shear offers significant potential for industrial non destructive testing applications, particularly in sealing technology and for the inspection of rotationally symmetric components.

2605.31085 2026-06-01 math.PR

On convergence to non normal laws for ergodic random fields

关于遍历随机场收敛到非正态律

Dalibor Voln{ý}

AI总结 研究遍历随机场中鞅差部分和的极限分布非正态性,将正态性的充要条件从二维推广到任意有限维,并给出改进的中心极限定理。

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AI中文摘要

对于具有完全交换滤过的Z^d作用,鞅差的归一化部分和依分布收敛(见[V19]),但即使作用是遍历的,极限律也未必是正态的。这一现象的解释已在[GLV]中研究,但通常仅限于二维。结果表明,非正态性与乘积类型I因子有关。这里我们将正态性的充要条件从二维推广到所有有限维,并给出L^2(I)正交补中鞅差正态性的充分条件。同时,给出了[V19]中d>2维随机场中心极限定理的改进和修正版本。

英文摘要

For Z d actions equipped with a completely commuting filtration, normalized partial sums of martingale differences converge in distribution (see [V19]) but even if the action is ergodic, the limit law need not be normal. Explication of this phenomenon has been studied in [GLV] but often in dimension 2 only. It turned out that the non normality is related to the factor of product type I. Here we extend the necessary and sufficient condition of normality from dimension 2 to all finite dimensions, as well as a sufficient condition of normality for martingale differences in the orthocomplement of L 2 (I). At the same time an improved and corrected version of the central limit theorem for random fields from [V19] with dimension d > 2 is given.

2605.31084 2026-06-01 cs.NI

Offloading L7 Policies to the Kernel

将L7策略卸载到内核

Laurin Brandner, Ayush Mishra, Sebastiano Miano, Aurojit Panda, Gianni Antichi, Laurent Vanbever

AI总结 提出L7FP,通过在内核空间自动合成eBPF数据平面来强制执行应用层策略,从而加速服务网格,无需修改代码,并透明回退到慢路径。

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AI中文摘要

服务网格最近已成为部署微服务的事实标准。从概念上讲,它们通过实现常见的网络机制(如加密、路由和负载均衡)并提供通过高级策略配置和组合这些机制的能力,为服务间的进程间通信(IPC)提供了统一的抽象。然而,支持这些策略会带来显著的性能成本,因为服务网格在数据路径上插入了代理(“sidecars”),导致大量上下文切换。本文提出了L7FP,一种服务网格的快速路径,它能够在内核空间中直接强制执行在现实环境中看到的绝大多数应用层策略。给定高级策略,L7FP自动合成基于eBPF的数据平面,在内核中强制执行这些策略。L7FP无需任何代码修改即可加速现有微服务,并透明地回退到现有服务代理(慢路径)以处理少数不受支持的策略。我们完整实现了L7FP,支持TLS和HTTP/2。与最先进的服务网格相比,L7FP将实际应用的中位请求延迟降低了最多6倍,同时吞吐量提高了3倍。

英文摘要

Service meshes have recently emerged as the de-facto standard for deploying microservices. Conceptually, they provide a uniform abstraction for inter-process communication (IPC) between services by implementing common networking mechanisms -- such as encryption, routing, and load balancing -- and by allowing these mechanisms to be configured and composed through high-level policies. Supporting these policies, however, comes with a significant performance cost, since service meshes interpose proxies (``sidecars'') on the data path, leading to numerous context switches. This paper presents L7FP, a fast path for service meshes which can enforce the vast majority of application-layer policies seen in the wild directly in kernel space. Given high-level policies, L7FP automatically synthesizes an eBPF-based data plane which enforces them in the kernel. L7FP accelerates existing microservices without any code modification, and transparently falls back to existing service proxies (the slow path) for the few unsupported policies. We fully implemented L7FP, with support for both TLS and HTTP/2. Compared to state-of-the-art service meshes, L7FP reduces the median request latency of realistic applications by up to $6\times$ while sustaining $3\times$ more throughput.

2605.31083 2026-06-01 physics.acc-ph

Attosecond Compression of Relativistic Electron Pulses via Continuous Harmonic Undulator Resonance

通过连续谐波波荡器共振实现相对论电子脉冲的阿秒压缩

Hao Sun, Xiaofan Wang, Xiaozhe Shen, Huaiqian Yi, Cheng-Ying Tsai, Weiqing Zhang, Xueming Yang

AI总结 提出一种广义谐波激光-电子相互作用机制,利用单周期波荡器中的非整数谐波调制实现阿秒压缩,同时保持束流质量和定时稳定性,为阿秒MeV UED提供可行途径。

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AI中文摘要

将兆电子伏特超快电子衍射(MeV UED)扩展到阿秒领域对于解析本征结构动力学至关重要,但需要同时控制电子脉冲持续时间和到达时间稳定性。这里,我们提出一种广义谐波激光-电子相互作用,将束流调制扩展到连续谐波区域。我们证明,通过单周期波荡器的高度失谐、非整数谐波调制比传统的整数谐波共振实现了更强的耦合效率。由中红外种子激光驱动,其波长是标称共振波长的一小部分,该机制实现了有效的纵向相空间操控。它促进了阿秒压缩,同时最小化激光引起的能量扩散,保持了高保真衍射所需的束流质量。此外,从同一光源导出调制激光和实验泵浦激光,从根本上锁定了它们的相对时序。模拟显示680阿秒脉冲持续时间和470阿秒到达时间抖动,为解析耦合电子-核动力学建立了可行的阿秒MeV UED路径。

英文摘要

Extending megaelectronvolt ultrafast electron diffraction (MeV UED) into the attosecond regime is essential for resolving intrinsic structural dynamics, yet requires simultaneously controlling electron-pulse duration and arrival-time stability. Here, we propose a generalized harmonic laser-electron interaction that extends beam modulation into a continuous harmonic regime. We demonstrate that highly detuned, non-integer harmonic modulation via a single-period undulator achieves stronger coupling efficiency than conventional integer-harmonic resonance. Driven by a mid-infrared seed laser whose wavelength is a small fraction of the nominal resonant wavelength, this mechanism enables effective longitudinal phase space manipulation. It facilitates attosecond compression with minimal laser-induced energy spread, preserving the beam quality required for high-fidelity diffraction. Furthermore, deriving both the modulation and experimental pump lasers from a common source intrinsically locks their relative timing. Simulations demonstrate 680-as pulse durations and 470-as arrival-time jitter, establishing a viable route to attosecond MeV UED for resolving coupled electron-nuclear dynamics.

2605.31081 2026-06-01 astro-ph.EP

Oxidation Constraints on Terrestrial Planet Formation from a Ring

来自环的氧化约束对类地行星形成的影响

Katherine I. Dale, Alessandro Morbidelli, Gabriel Nathan, Jason Woo, David Nesvorný, David C. Rubie

AI总结 研究通过分析行星胚胎从窄环吸积不同氧化状态星子的过程,发现地球的氧化状态约束要求氧化物质在行星形成末期才被输送到环中,以匹配硅酸盐地球的组成。

Comments Accepted in Icarus, 20 pages (including appendix), 11 figures (including appendix) and two tables (appendix)

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AI中文摘要

当今太阳系包含来自不同母体的、氧化程度各异的陨石。先前关于行星生长和分异过程中亲铁元素在地幔和地核之间分配的研究(例如 Rubie et al., 2011)表明,地球必须先吸积还原体,后吸积氧化体。在这里我们表明,如果类地行星由窄环的星子形成,无论假设环中氧化程度的日心梯度如何,这一条件都无法满足。原因是行星胚胎迅速从整个环宽度吸积星子,同时包含还原和氧化物质。所有行星胚胎的部分氧化状态导致与整体硅酸盐地球(BSE)的组成不匹配,因为氧逸度强烈影响亲铁元素的分配。我们证明,重现BSE组成要求还原和氧化储库在胚胎形成几乎完成之前保持分离。因此,在盘寿命末期将氧化物质输送到类地行星形成环是任何成功的类地行星形成动力学模型的关键要求。

英文摘要

The present-day solar system comprises meteorites with varying oxidation levels, derived from different parent bodies. Previous studies (e.g. Rubie et al., 2011) of the partitioning of siderophile elements between mantle and core during planetary growth and differentiation showed that Earth must accrete reduced bodies first and oxidised bodies later. Here we show that, if the terrestrial planets formed from a narrow ring of planetesimals, this condition is not fulfilled, whatever heliocentric gradient of oxidation is assumed in the ring. The reason is that planetary embryos quickly accrete planetesimals from the whole width of the ring, incorporating both reduced and oxidised material. The partially oxidised state of all planetary embryos leads to mismatches with the composition of the bulk silicate Earth (BSE) because oxygen fugacity strongly affects the partitioning of siderophile elements. We demonstrate that reproducing the BSE composition requires reduced and oxidised reservoirs to remain segregated until embryo formation is almost complete. The delivery of oxidised material to the terrestrial planet-forming ring towards the end of the disc's lifetime is therefore a key requirement of any successful dynamical model of terrestrial planet formation.

2605.31079 2026-06-01 physics.ao-ph physics.data-an stat.ML

Forecasting threshold exceedance of atmospheric variables at a specific location

特定地点大气变量阈值超出的预测

Roberta Baggio, Jean-François Muzy

AI总结 本研究比较了直接概率法和全分布概率法在预测特定地点大气变量(如温度和风速)阈值超出时的表现,发现全分布方法在极端事件中更优,并指出其优势源于对条件分布整体特征的准确捕捉。

Comments 24 pages, 8 Figures, 4 tables

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AI中文摘要

本研究比较了两种方法论方法,用于在给定地点预测大气变量(如温度和风速)的阈值超出:(i)直接概率法,将超出视为二元分类问题;(ii)全分布概率法,对目标变量的完整条件概率律进行建模。通过理论分析和在玩具模型上的数值模拟,以及来自法国东南部MeteoNet数据集(2016-2018)的真实数据,我们证明全分布方法在罕见极端事件中始终优于直接方法。这一优势源于全分布方法能够从中等和轻度强度事件中有效学习条件分布的参数,从而在尾部实现更好的校准和区分。我们发现,所选分布的具体参数形状相对于准确捕捉其整体属性(即均值和方差)的可预测变化而言,起次要作用。这种经验上的不可区分性也揭示了驱动大气极值的物理机制,表明极端超出主要由整个分布的显著条件位移驱动,而非静态气候学中不可预测的肥尾异常。我们的结果在强地表风速和强小时降雨量上均得到验证,并使用适当评分规则(Brier分数、对数分数)和确定性技能分数(Peirce技能分数、CSI、HSS)评估性能。这些发现强调了全概率分布建模在罕见事件预测中的关键重要性,并为改进业务气象学中的极端天气预测提供了实用指导。

英文摘要

This study compares two methodological approaches for predicting, at a given site, threshold exceedances of atmospheric variables such as temperature and wind speed: (i) direct probabilistic methods, which treat exceedance as a binary classification problem, and (ii) full distribution probabilistic methods, which model the complete conditional probability law of the target variable. Using theoretical analysis and numerical simulations on a toy model, alongside real-world data from the MeteoNet dataset (2016--2018) for southeastern France, we demonstrate that the full distribution approach consistently outperforms the direct method for rare, extreme events. This advantage arises because the full distribution approach effectively learns the parameters of the conditional distribution from moderate and mild intensity events, thereby achieving better calibration and discrimination in the tails. We find that the specific parametric shape of the chosen distribution plays a secondary role compared to accurately capturing predictable shifts in its bulk properties (i.e., mean and variance). This empirical indistinguishability is also informative about the physical mechanics driving atmospheric extremes, suggesting that extreme exceedances are primarily driven by significant conditional displacements of the entire distribution rather than by unpredictable, fat-tailed anomalies within a static climatology. Our results are validated for both strong surface wind speeds and intense hourly rainfall, with performance evaluated using proper scoring rules (Brier score, logarithmic score) and deterministic skill scores (Peirce Skill Score, CSI, HSS). These findings highlight the critical importance of modeling the full probability distribution for rare-event forecasting and provide practical guidance for improving extreme weather prediction in operational meteorology.

2605.31077 2026-06-01 astro-ph.GA

Super-Eddington accretion of black holes in early nuclear bursts gives birth to Little Red Dots

早期核爆发中的超爱丁顿吸积黑洞孕育了小红点

Yangyao Chen, Houjun Mo

AI总结 本研究基于ΛCDM宇宙学模型,通过物理判据选择预测的黑洞群体,将其与JWST发现的小红点(LRD)关联,发现高红移LRD自然来自核爆发期间超爱丁顿吸积的黑洞子集,并预测了LRD的质量分布、数密度演化及后代多样性。

Comments 11 pages, 3 figures; submitted to ApJL; comments are welcome

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AI中文摘要

在最近的一篇论文中,Chen等人开发了一个框架,用于在ΛCDM宇宙学背景下模拟超大质量黑洞(BHs)的播种和增长。在这里,我们使用一组物理驱动的判据来选择预测的黑洞群体,并将其与JWST发现的小红点(LRDs)联系起来。我们表明,高红移($z$)的LRD群体自然来自核爆发期间具有超爱丁顿吸积的黑洞子集。该模型表明,观测到的LRD是同一子集中更大数量、更暗弱黑洞群体的“冰山一角”。该模型对LRD群体做出了具体预测,例如其黑洞和宿主星系/暗晕的质量分布,以及其数密度的分段红移演化。模型的宇宙学背景还使我们能够将观测到的LRD群体与其前身(它们的黑洞种子)和较低红移的后代黑洞、星系和暗晕联系起来。大多数红移$z\sim 5$的LRD是在$z \gtrsim 20$时通过直接坍缩黑洞或来自Pop-III恒星的对不稳定超新星播种的,并通过核爆发增长到$M_{ m BH} \approx 10^5$--$10^7\,{ m M}_\odot$(在其观测红移时)。预测LRD具有多样化的后代,从紧凑矮星系到$z=0$时的最亮团星系(BCGs)。这些预测与当前观测一致,并可进一步检验。该模型成功表明,这里呈现的结果为构建LRD群体的详细模型提供了坚实基础。

英文摘要

In a recent paper, Chen et al. developed a framework for modeling the seeding and growth of supermassive black holes (BHs) in the context of $Λ$CDM cosmogony. Here, we use a set of physically motivated criteria to select a population of predicted BHs and link them to Little Red Dots (LRDs) discovered by JWST. We show that the LRD population at high redshift ($z$) emerges naturally from a subset of BHs with super-Eddington accretion during nuclear bursts. The model suggests that the observed LRDs are the "tip of the iceberg" of a much larger population of less luminous BHs in the same subset. The model makes specific predictions for the LRD population, such as the mass distributions of their BHs and host galaxies/halos, and the piece-wise redshift evolution of their number density. The cosmological context of the model also allows us to link the observed LRD population to their progenitors (their BH seeds) and lower-$z$ descendant BHs, galaxies and halos. Most LRDs at $z\sim 5$ are seeded at $z \gtrsim 20$ through direct-collapse BHs or pair-instability supernovae from Pop-III stars, and have grown to $M_{\rm BH} \approx 10^5$--$10^7\,{\rm M}_\odot$ through nuclear bursts by their observed redshift. LRDs are predicted to have diverse descendants, ranging from compact dwarf galaxies to brightest cluster galaxies (BCGs) at $z=0$. These predictions are consistent with current observations and can be further tested. The success of this model indicates that the results presented here provide a robust foundation for building detailed models of the LRD population.

2605.31076 2026-06-01 math.FA

Operator-norm bounds and a quadratic lower-growth example for the special Euclidean algebra se(3)

特殊欧几里得代数 se(3) 的算子范数界和二次下增长例子

Sooraj K. C, Vivek Mishra

AI总结 本文证明了特殊欧几里得代数 se(3) 上指数映射参数化的算子范数和梯度 Lipschitz 界,并构造了一个二次下界例子,表明其增长行为介于紧李代数和含双曲元素的李代数之间。

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AI中文摘要

我们证明了特殊欧几里得代数 se(3) 上指数映射参数化的算子范数和梯度 Lipschitz 界,并提供了一个中间多项式增长行为的显式例子。利用 SO(3) 左 Jacobian 的收缩性质,我们证明了对所有 theta 属于 se(3),有 ||exp(theta)||_op <= 1 + ||theta||_F。然后我们推导了一个自包含的 O(R^2) 上界,用于梯度 Lipschitz 常数,显式常数为 4.02,并构造了一个目标函数 J*,满足对 R >= 2 有 L_J*(R; se(3)) >= 0.0505 R^2。这些结果将 se(3) 置于紧李代数(Lipschitz 常数有界)和含双曲元素的李代数(指数增长)之间。上界和下界是针对不同的目标函数类获得的;未声明极小极大最优性。

英文摘要

We prove operator-norm and gradient Lipschitz bounds for exponential-map parameterizations on the special Euclidean algebra se(3), providing an explicit example of intermediate polynomial growth behavior. Using the contraction property of the SO(3) left Jacobian, we show that ||exp(theta)||_op <= 1 + ||theta||_F for all theta in se(3). We then derive a self-contained O(R^2) upper bound for the gradient Lipschitz constant, with explicit constant 4.02, and construct an objective J* satisfying L_J*(R; se(3)) >= 0.0505 R^2 for R >= 2. These results place se(3) between compact Lie algebras, where the Lipschitz constant remains bounded, and Lie algebras with hyperbolic elements, where it grows exponentially. The upper and lower bounds are obtained for different objective classes; no minimax optimality claim is made.

2605.31074 2026-06-01 physics.optics quant-ph

Preventing the Breakdown of Tight-Binding Waveguide Optics by Löwdin Orthogonalization

通过Löwdin正交化防止紧束缚波导光学的崩溃

Konrad Tschernig, Florian H. Huber, Janik Wolters, Jasmin Meinecke

AI总结 针对紧束缚近似中非正交导模导致的标准模型与波动方程解不匹配问题,提出基于Löwdin正交化的修正TB框架,恢复标准本征值问题并精确模拟光束传播。

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AI中文摘要

光学的许多进展依赖于紧束缚近似,它通过检查单个单模子结构的导模之间的耦合(也称为耦合模理论)来简化复杂系统行为的描述和预测。然而,当波导靠得很近或考虑更大的阵列时,单个波导的导模形成正交基的潜在假设会失效。在这项工作中,我们系统地分析了这种非正交性的后果,并表明它导致了一个涉及重叠矩阵的广义本征值问题,从而引起标准TB模型与近轴波动方程解之间的根本性不匹配。为了解决这个问题,我们引入了一个基于Löwdin正交化的修正TB框架,该框架从非正交导模构造一个正交归一基,同时最小程度地改变其物理形状并保持其对称性。由此产生的Löwdin-TB方法恢复了标准本征值问题,并在各种系统尺寸和波导间距下与精确光束传播模拟取得了极好的一致性。此外,它捕捉到了标准方法中缺失的重要物理效应,如增强的长程耦合和非平凡跳跃相位。

英文摘要

Many advancements in optics have relied on the tight-binding approximation, which simplifies the description and prediction of complex system behaviors. This approximation describes the dynamics of the total light field by examining the coupling between the guided modes of individual single-mode substructures -- also known as coupled mode theory. However, the underlying assumption, that the guided modes of individual waveguides form an orthogonal basis, breaks down when waveguides are brought into close proximity or when larger arrays are considered. In this work, we systematically analyze the consequences of this non-orthogonality and show that it leads to a generalized eigenvalue problem involving an overlap matrix, causing a fundamental mismatch between the standard TB model and solutions of the paraxial wave equation. To resolve this issue, we introduce a modified TB framework based on the Löwdin orthogonalization, which constructs an orthonormal basis from the non-orthogonal guided modes while minimally altering their physical shape and preserving their symmetry properties. The resulting Löwdin-TB method restores the standard eigenvalue problem and yields excellent agreement with exact beam propagation simulations across a wide range of system sizes and waveguide separations. Furthermore, it captures important physical effects, such as enhanced long-range coupling and nontrivial hopping phases, that are absent in the standard approach.

2605.31072 2026-06-01 econ.TH cs.GT cs.MA econ.EM

Comparing Market Mechanism Efficiencies

比较市场机制效率

Irene Aldridge

AI总结 通过博弈论框架比较连续双向拍卖(透明订单簿与不透明订单簿)和定期批量拍卖的福利效率,证明在中等到达率和有限逆向选择下,暗池优于其他机制。

Comments 79 pages

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AI中文摘要

我们开发了一个博弈论框架,比较三种市场机制的福利效率:具有透明订单簿的连续双向拍卖(公开交易所)、不透明订单簿(暗池)和定期批量拍卖。每种机制都被建模为一个排队系统,其中异质交易者在执行价格、等待成本和交易成本之间进行权衡。我们的主要结果表明,在中等到达率和有限逆向选择下,暗池在事前总福利上优于其他两种替代方案。可观察的订单簿产生了代价高昂的战略性时机博弈,交易者延迟或提前提交以优化其在队列中的位置,从而产生浪费的社会等待成本。不透明的订单簿通过信息设计消除了这些时机博弈。我们正式刻画了每种机制中的均衡策略,并证明了福利排序 $W^{DARK} > W^{LIT} > W^{BATCH}$。扩展部分包含了信息不对称和内生场所选择。结果展示了信息结构和服务的纪律如何共同决定战略匹配环境中的效率。

英文摘要

We develop a game-theoretic framework that compares welfare efficiency across three market mechanisms: continuous double auctions with transparent order books (lit exchanges), opaque order books (dark pools), and periodic batch auctions. Each mechanism is modeled as a queuing system where heterogeneous traders face trade-offs between the execution price, waiting costs, and transaction costs. Our main result establishes that under moderate arrival rates and bounded adverse selection, dark pools dominate both alternatives in aggregate ex-ante welfare. Observable order books create costly strategic timing games in which traders delay or rush submissions to optimize their position in the queue, generating wasteful social waiting costs. Opaque order books eliminate these timing games through information design. We formally characterize the equilibrium strategies in each mechanism and prove the welfare ranking $W^{DARK} > W^{LIT} > W^{BATCH}$. Extensions incorporate asymmetric information and endogenous venue choice. The results demonstrate how the information structure and the discipline of the service jointly determine efficiency in strategic matching environments.

2605.31060 2026-06-01 astro-ph.SR astro-ph.EP

Chemical paradox in a binary system: Exploring metal enrichment in HD 81809B

双星系统中的化学悖论:探索HD 81809B的金属增丰

Nuno Moedas, Maria Pia Di Mauro

AI总结 本研究通过恒星演化模型模拟行星吞噬事件,解释双星系统HD 81809中次星金属丰度异常,发现需吞噬25-75倍地球质量的金属物质才能匹配观测,但锂丰度限制吞噬量小于6倍地球质量。

Comments 11 pages, 9 figures, 6 tables, accepted in A&A

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AI中文摘要

HD 81809系统呈现奇特的化学组成,其两个子星之间金属丰度差异巨大:主星金属丰度低([Fe/H]=-0.57 dex),而次星金属丰度接近太阳([Fe/H]=0.0 dex)。本研究探究HD 81809B的化学增丰是否可以通过行星吞噬事件来解释,且与恒星的演化约束一致。利用恒星天体物理学实验模块(MESA)代码,我们对HD 81809B进行建模,引入不同质量和化学混合物的吸积事件,以了解它们对表面化学成分的影响。我们的模拟表明,重现HD 81809B观测到的表面[Fe/H]需要一次大规模的吸积事件。要达到观测到的金属丰度,该恒星必须在当前年龄附近吞噬25到75 $M_\oplus$的金属。吸积使恒星模型的有效温度更接近观测值;然而,锂的结果过度增丰。为了重现该元素的丰度,恒星必须吞噬少于6 $M_\oplus$的物质。这些结果表明,行星吸积事件在HD 81809B的演化中是可能的;然而,吸积物质的化学成分可能与本文采用的假设不同。尽管如此,本研究强调了在模拟化学异常双星系统时考虑此类外部事件的重要性。

英文摘要

The HD 81809 system presents peculiar chemical composition with a large metallicity difference between its two components: the primary has low metallicity ([Fe/H]=-0.57 dex), while the secondary has approximately solar metallicity ([Fe/H]=0.0 dex). This study investigates whether the chemical enrichment of HD 81809B can be reconciled by a planetary engulfment event, consistent with the star's evolutionary constraints. Using Modules for Experiments in Stellar Astrophysics (MESA) code, we model HD 81809B introducing accretion events with different ranges of masses and chemical mixtures to understand their impact in the surface chemical composition. Our simulation shows that reproducing the observed surface [Fe/H] in HD 81809B requires a substantial accretion event. To reach the observed metallicity, the star must engulf 25 to 75 $M_\oplus$ of metals near its current age. Accretion brings the effective temperature of stellar models closer to the observed one; however, the lithium results over-enriched. In order to reproduce the abundance of this element, the star must accrete less than 6 $M_\oplus$. These results suggest that a planetary accretion event is plausible in the evolution of HD 81809B; however, the chemical composition of the accreted material may differ from the assumptions adopted here. Nevertheless, this study emphasizes the importance of considering such external events when modeling chemically anomalous binary systems.

2605.31059 2026-06-01 eess.SP cs.IT math.IT

CRB-Optimal Arrays and Waveforms in Active Sensing: Role of Redundancy and Spatial Covariance of Array Geometry

主动感知中的CRB最优阵列与波形:冗余性与阵列几何空间协方差的作用

Ids van der Werf, Robin Rajamäki, Geert Leus

AI总结 本文通过分析正交和相干波形下线性及平面阵列的Cramér-Rao界,揭示了最优阵列几何的冗余性本质,并推导了给定传感器总数下的最优收发分配方案。

Comments Accepted for publication in IEEE Transactions on Signal Processing

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AI中文摘要

本文刻画了使用正交和相干波形的线性及平面阵列最优设计的性能极限。对于正交波形,我们证明单目标Cramér-Rao界(CRB)取决于发射(Tx)和接收(Rx)阵列所谓的空间方差之和,或者等价地,取决于由虚拟传感器多重性加权的和协阵列的空间方差。这表明CRB最优几何本质上是冗余的,突出了参数估计中均方误差(MSE)与可辨识性之间的基本权衡。此外,我们推导了给定传感器总数下的最优Tx-Rx传感器分配,并表明即使对于非冗余阵列,非均衡分配(偏向Rx)也是最优的,这挑战了传统设计。我们将结果扩展到平面阵列,提供了Tx和Rx阵列空间协方差应满足的新的一般条件,以使最优波形将功率导向目标方向。另外,我们建立了丢番图方程与具有相等CRB的阵列几何之间的联系,并给出了设计此类阵列的构造性方法。我们的工作为新兴主动传感多输入多输出系统中的最优阵列与波形设计提供了新的指导和见解。

英文摘要

This paper characterizes the performance limits of optimal array designs using orthogonal and coherent waveforms for both linear and planar arrays. For orthogonal waveforms, we show that the single-target Cramér-Rao Bound (CRB) depends on the sum of the so-called spatial variances of the transmit (Tx) and receive (Rx) arrays, or equivalently, the spatial variance of the sum co-array weighted by the multiplicities of the virtual sensors. This reveals that CRB-optimal geometries are inherently redundant, highlighting a fundamental trade-off between mean squared error (MSE) and identifiability in parameter estimation. Moreover, we derive optimal Tx-Rx sensor allocations given a total sensor budget and show that unequal allocation (favoring the Rx) is optimal even for nonredundant arrays, questioning conventional designs. We extend our results to planar arrays, providing a new general condition that the spatial covariances of the Tx and Rx arrays should satisfy for the optimal waveforms to direct power in the target direction. Additionally, we establish a connection between Diophantine equations and array geometries with equal CRB, along with a constructive method for designing such arrays. Our work provides new guidelines for and insights into optimal array and waveform design with relevance in emerging active sensing multiple-input multiple-output systems.

2605.31055 2026-06-01 math.NA cs.NA

A novel Chebyshev collocation method for elliptic -type differential equations with degenerate coefficient

一种用于退化系数椭圆型微分方程的切比雪夫配点法

Enze Yuan, Huantian Xie, Ziwu Jiang, Jianwei Zhou

AI总结 提出一种基于加权正交切比雪夫多项式的配点法,用于求解带退化系数和齐次Dirichlet边界条件的椭圆型方程,通过稀疏刚度矩阵实现高效计算,并给出谱精度的先验误差估计。

Comments 22 pages

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AI中文摘要

针对带退化系数和齐次Dirichlet边界条件的椭圆型微分方程,提出了一种新的配点格式。使用加权正交切比雪夫多项式作为基函数,得到的刚度矩阵具有稀疏结构,从而能够进行高效的直接计算。通过正交投影,进行了严格的分析,推导出两种范数下谱精度的先验误差估计。此外,进行了大量的数值实验,并与误差数据、收敛速度、条件数和$N$-$\log$曲线进行了比较,以确认理论分析结果。我们的方法实现了谱精度,并有效处理了边界奇异性,理论分析和数值实验均证明了这一点。

英文摘要

A novel collocation scheme is presented for elliptic-type differential equations with degenerate coefficients and homogeneous Dirichlet boundary conditions. The use of weighted orthogonal Chebyshev polynomials for the basis functions leads to stiffness matrices with sparse structure, enabling efficient direct calculations. By an orthogonal projection, rigorous analyses are devoted to deriving a-priori error estimates of spectral accuracy in two norms. Furthermore, ample numerical experiments are conducted and compared with error data, convergence rates, condition numbers and $N$-$\log$ curves to confirm the theoretical analyses results. Our proposed method achieves spectral accuracy and handles boundary singularities efficiently, as demonstrated by theoretical analyses and numerical experiments.

2605.31052 2026-06-01 astro-ph.GA

Unveiling the population of massive quenched galaxies at $z\ge2$ in the COLIBRE simulations -- II. The role of AGN feedback and environment on their emergence

COLIBRE模拟中$z\ge2$大质量熄灭星系群体的揭示——II. AGN反馈和环境对其出现的作用

Ángel Chandro-Gómez, Claudia del P. Lagos, Chris Power, Willian M. Baker, Alejandro Benítez-Llambay, Evgenii Chaikin, Harry G. Chittenden, Camila Correa, Carlos S. Frenk, Filip Huško, Kei Ito, Robert J. McGibbon, Themiya Nanayakkara, Sylvia Ploeckinger, Alexander J. Richings, Matthieu Schaller, Joop Schaye, James W. Trayford, Francesco Valentino

AI总结 利用COLIBRE宇宙学流体动力学模拟,研究AGN反馈和环境在早期大质量熄灭星系形成中的作用,发现AGN反馈是主要熄灭机制,但热模式和混合模式效果不同,且环境密度影响黑洞吸积和反馈功率。

Comments Submitted for publication in MNRAS. This work is Part II of a two-paper series (Part I: arXiv:2512.16208). 23 pages (17 of main body and 6 of appendices). Comments welcome

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AI中文摘要

早期($z \gtrsim 2$)大质量($M_{\star} \gtrsim 10^{10}\,\mathrm{M_{\odot}}$)熄灭星系(MQGs)对当前星系形成模型提出了挑战。在本系列中,我们利用新的COLIBRE宇宙学流体动力学模拟研究这些系统。继第一篇论文中其预测与观测大致一致后,第二篇论文探讨了在COLIBRE中驱动星系变得大质量并熄灭的过程,识别出活动星系核(AGN)反馈是所实施的热模式(L200m6模拟)和混合模式(热+喷流,L200m7h模拟)AGN反馈模型中的主要熄灭机制。然而,两种模型表现不同:热模式在$z>3$时有效熄灭大质量星系,而混合模式效果较差,因为黑洞(BHs)在早期宇宙中增长较慢,且主导反馈能量的喷流成分在更长的时间尺度上作用于星系。两种模型都预测类星体MQGs($L_{\rm bol}\gtrsim10^{45}\,\mathrm{erg\,s^{-1}}$的AGN),其中最明亮的系统与最近熄灭的星系相关。与类似质量的恒星形成星系相比,MQGs拥有更大质量的黑洞并表现出更高的恒星形成效率。这些差异主要源于它们熄灭前的环境,特别是在局域($\rm 0.3\,cMpc$)到中等尺度($\rm 1.0\,cMpc$)上,过密区域与增强的气体流入、更高的黑洞吸积以及因此更强的反馈功率相关。我们发现,在L200m6(L200m7h)中,约$54\%$($20\%$)的$z=3$ MQGs作为$z=0$星系的主要前身存活下来,尽管多达$56\%$($60\%$)在$z<3$时经历了复苏事件。我们的结果强调了黑洞增长、AGN反馈和环境在驱动早期宇宙快速熄灭中的核心作用。

英文摘要

Early ($z \gtrsim 2$) Massive ($M_{\star} \gtrsim 10^{10}\,\mathrm{M_{\odot}}$), Quenched Galaxies (MQGs) challenge current galaxy formation models. In this series, we study these systems using the new COLIBRE cosmological hydrodynamical simulations. Following the broad agreement between its predictions and observations found in the first paper, this second paper explores the processes driving galaxies to become massive and quenched in COLIBRE, identifying Active Galactic Nucleus (AGN) feedback as the primary quenching mechanism in both the thermal (L200m6 simulation) and hybrid (thermal+jet, L200m7h simulation) AGN feedback models implemented. However, the two models behave differently: while the thermal model efficiently quenches massive galaxies at $z>3$, the hybrid model is less effective because black holes (BHs) grow more slowly in the early Universe, and the jet component, which dominates the feedback energy, acts on longer timescales to impact galaxies. Both models predict quasar-like MQGs (AGN with $L_{\rm bol}\gtrsim10^{45}\,\mathrm{erg\,s^{-1}}$), with the most luminous systems associated with more recently quenched galaxies. Compared to star-forming galaxies of similar mass, MQGs host more massive BHs and exhibit higher star formation efficiencies. These differences arise primarily from their environments before quenching, particularly at local ($\rm 0.3\,cMpc$) to intermediate scales ($\rm 1.0\,cMpc$), where overdense regions are associated with enhanced gas inflows, higher BH accretion and, hence, feedback power. We find that about $54\%$ ($20\%$) of the $z=3$ MQGs survive as the main progenitors of $z=0$ galaxies, although up to $56\%$ ($60\%$) experience rejuvenation episodes at $z<3$ in L200m6 (L200m7h). Our results highlight the central role of BH growth, AGN feedback and environment in driving rapid quenching in the early Universe.

2605.31047 2026-06-01 math.CO

$λ$-Chromatic Polynomials and Polytope Geometry

$λ$-色多项式与多面体几何

Annayat Ali, Rameez Raja

AI总结 本文研究图的$λ$-色多项式,该多项式计数使用给定有限颜色集的不同$L(2,1)$-着色数量,通过内部-外部多面体框架下的格点枚举给出组合解释,并利用格路枚举和块-间隙技术计算完全图、完全二部图及多部图的$λ$-色多项式。

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AI中文摘要

本文研究了图的$\textit{$λ$-色多项式}$的概念,该多项式枚举使用给定有限颜色集的不同$L(2,1)$-着色数量。我们证明具有$n$个顶点的图的$λ$-色多项式是$n$次首一多项式,并通过内部-外部多面体框架下的格点枚举给出组合解释。此外,我们利用格路枚举计算完全图$K_n$的$λ$-色多项式,并开发了一种块-间隙技术来推导完全二部图和多部图的$λ$-色多项式。我们的方法统一了几何、组合和代数方法,为各种图族的$λ$-着色提供了系统处理。

英文摘要

In this paper, we investigate the notion of the \textit{$λ$-chromatic polynomial} of a graph, which enumerates the number of distinct $L(2,1)$-colorings using colors from a prescribed finite set. We prove that the $λ$-chromatic polynomial of a graph with $n$ vertices is a monic polynomial of degree $n$ and provide a combinatorial interpretation via lattice point enumeration within the framework of inside-out polytopes. Moreover, we compute the $λ$-chromatic polynomial of complete graphs $K_n$ using lattice path enumeration, and we develop a block-gap technique to derive the $λ$-chromatic polynomials for complete bipartite and multipartite graphs. Our approach unifies geometric, combinatorial, and algebraic methods to provide a systematic treatment of $λ$-colorings across various families of graphs.

2605.31045 2026-06-01 physics.ed-ph

Data evaluation processes of different-sized datasets: an eye-tracking with concurrent think-aloud study

不同规模数据集的数据评估过程:一项眼动追踪与并发出声思考研究

Gregor Benz, Sarah Taha, Andreas Vorholzer

AI总结 本研究通过眼动追踪和并发出声思考,分析了大学生在图表中评估小规模与大规模数据集的过程,发现数据集大小与数据模式可见性相互作用,大规模数据集促进基于模式和趋势的评估,而小规模数据集则导致对单点的过度关注和不确定性表达。

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AI中文摘要

考虑到物理课堂中数字工具和测量数据的日益普及,学生更频繁地面对较大的数据集。虽然现有文献通常认为处理大量数据更复杂,但Benz、Ludwig和Vorholzer [Sci. Ed. 119, 1669-1700 (2025)] 的最新工作表明,当数据以图表形式呈现时,情况未必如此。在此基础上,本研究调查了学生如何评估图表表示中的小规模和大规模数据集。采用过程导向的方法,我们通过眼动追踪和并发出声思考分析了$N=20$名大学物理学生的数据评估过程。结果表明,数据集大小与数据中模式可见性的相互作用系统地塑造了学生推理测量数据的方式。较大的数据集支持更多基于模式和趋势的评估,并能导致更明确的结论。相反,较小的数据集与对单个测量点的更强关注以及不确定性表达的增多相关,包括明确的“数据需求”,以及对单个测量的过度解释/过度加权。观察到的从不确定性相关和局部聚焦评估向更整合和基于趋势/模式推理的转变表明,较大的数据集可能有助于学生将多个数据点整合为对测量数据更连贯的解释。总体而言,该研究有助于从过程导向的角度理解学生在物理教育中如何处理测量数据。

英文摘要

Considering the increasing availability of digital tools and measurement data in physics classrooms, students are more frequently confronted with larger datasets. While existing literature often assumes that working with large amounts of data is more complex, recent work by Benz, Ludwig, and Vorholzer [Sci. Ed. 119, 1669-1700 (2025)] suggests that this is not necessarily the case when data are presented in diagrams. Building on this, the present study investigates how students evaluate small and large datasets in diagrammatic representations. Using a process-oriented approach, we analyzed the data evaluation processes of $N=20$ university physics students via eye-tracking and concurrent think-aloud. The results indicate that dataset size, in interaction with the visibility of patterns in the data, systematically shapes how students reason with measurement data. Larger datasets support more pattern- and trend-based evaluation and can lead to more unambiguous conclusions. In contrast, smaller datasets are associated with a stronger focus on single measurement points and increased expressions of uncertainty, including an articulated "need for data," alongside an overinterpretation/overweighting of single measurements. The observed shift from uncertainty-related and locally focused evaluation toward more integrative and trend/pattern-based reasoning suggests that larger datasets may support students in integrating multiple data points into more coherent interpretations of measurement data. Overall, the study contributes to a process-oriented understanding of how students engage with measurement data in physics education.

2605.31038 2026-06-01 physics.optics

Towards Neuromorphic Event-Based Sensing for High-Speed Multi-Spectral Classification and Tracking of Microparticles

面向高速多光谱微粒分类与追踪的神经形态事件驱动传感

Joana M. Teixeira, Tomás Lopes, Tiago D. Ferreira, Catarina S. Monteiro, Pedro A. S. Jorge, Nuno A. Silva

AI总结 提出一种集成空间复用RGB滤光片掩模与异步事件传感器的微流控平台,实现亚毫秒时间分辨率下多分散微粒的运动与光谱信息同步提取,分类准确率达82%,数据带宽降低240倍以上。

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AI中文摘要

传统的基于图像的微流控系统在通量、成像速度和数据带宽之间存在固有折衷,限制了其在无明显运动模糊或数据量过大的情况下监测高速流的能力。事件驱动传感已成为一种高速、低功耗的替代方案,但迄今为止主要局限于追踪单分散球形颗粒。在本工作中,我们引入了一种微流控传感平台,利用神经形态成像方法,能够从多分散微粒中同时提取运动学和光谱信息。通过将空间复用的RGB滤光片掩模与异步事件传感器集成,光谱特征和运动直接在传感阶段编码,无需图像重建或基于学习的推理。该系统实现了亚毫秒时间分辨率,并在广泛的颗粒尺寸和流速范围内(包括非层流条件下)保持稳健的分类性能,在0.08-0.18毫米范围内对彩色颗粒的分类准确率高达82%。与传统高速成像相比,事件驱动架构将数据带宽降低了240倍以上,同时保持了460 mm^2/s的面积通量。通过提供计算高效且低延迟的颗粒表征,该框架为临床诊断和环境监测中高速、无标记的异质分析物筛选的可扩展解决方案铺平了道路。

英文摘要

Conventional image-based microfluidic systems face an inherent trade-off between throughput, imaging speed, and data bandwidth, limiting their ability to monitor high-velocity flows without significant motion blur or prohibitive data generation. Event-based sensing has emerged as a high-speed, low-power alternative, but has so far been largely restricted to tracking monodisperse, spherical particles. In this work, we introduce a microfluidic sensing platform that enables the simultaneous extraction of kinematic and spectral information from polydisperse microparticles using a neuromorphic imaging approach. By integrating a spatially multiplexed RGB filter mask with an asynchronous event-based sensor, spectral signature and motion are encoded directly at the sensing stage, eliminating the need for image reconstruction or learning-based inference. The system achieves sub-millisecond temporal resolution and maintains robust classification performance across a broad range of particle sizes and flow velocities, including under non-laminar conditions, reaching up to 82% accuracy for classification of colored particles within the 0.08-0.18 mm range. The event-driven architecture reduces data bandwidth by >240x compared to conventional high-speed imaging, while sustaining an area throughput of 460 mm^2/s. By providing a computationally efficient and low-latency particle characterization, this framework paves the way for a scalable solution towards high-speed, label-free screening of heterogeneous analytes in clinical diagnostics and environmental monitoring.

2605.31037 2026-06-01 cond-mat.mtrl-sci

Spin-Spiral Enhancement of Ultrafast Light-Polarization-Robust Magnetization

自旋螺旋增强超快光偏振鲁棒磁化

Yirui Lu, Zeyu Jiang, Bing Huang

AI总结 本文通过对称性约束规则和实时含时密度泛函理论计算,揭示了自旋螺旋磁体中光偏振鲁棒磁化的机制,并发现激光激发可诱导自旋螺旋单层NiI₂中的实空间退磁、旋转和振荡。

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AI中文摘要

超快光驱动磁化是量子磁光学的前沿领域,传统上依赖于圆偏振激光提供外部角动量。尽管越来越多的努力旨在实现对外部光激发形式不敏感的光偏振鲁棒(LPR)磁化,但其潜在机制仍不清楚。在这里,我们建立了反铁磁系统中LPR磁化的对称性约束规则。通过实时含时密度泛函理论计算,我们观察到自旋螺旋磁体中的强LPR磁化及其在共线反铁磁体中的抑制,证实了我们的理论。引人注目的是,激光激发诱导自旋螺旋单层NiI$_2$中原子自旋的实空间退磁、旋转和振荡,而在传统共线反铁磁体中旋转被大幅抑制。我们的工作揭示了一种不依赖于光极化的超快磁化的新型微观途径,为先进的飞秒自旋控制铺平了道路。

英文摘要

Ultrafast light-driven magnetization, a frontier in quantum magneto-optics, has traditionally relied on circularly polarized lasers to provide external angular momentum. While increasing efforts have aimed to achieve light-polarization-robust (LPR) magnetization that is insensitive to the form of external light excitation, the underlying mechanism remains largely unclear. Here, we establish the symmetry-constrained rule for LPR magnetization in antiferromagnetic systems. Through real-time time-dependent density functional theory calculations, we observe the strong LPR magnetization in spin-spiral magnets and its suppression in collinear antiferromagnets, confirming our theory. Strikingly, laser excitation induces real-space demagnetization, rotation, and oscillation of atomic spins in spin-spiral monolayer NiI$_2$, whereas rotation is largely suppressed in conventional collinear antiferromagnets. Our work reveals a novel microscopic pathway for ultrafast magnetization that is independent of light polarization, paving the way for advanced femtosecond spin control.