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科学智能、蛋白质、分子、药物、材料、气象、物理和数学 AI。

今日/当前日期收录 478 信号源:cs.LG, q-bio, physics, cond-mat, math, stat.ML

1. 材料化学 5 篇

2606.19903 2026-06-19 cond-mat.mes-hall 新提交 80%

Symmetry enforced quantum spin Hall effect in Altermagnets

交变磁体中对称性强制实现的量子自旋霍尔效应

Fanzheng Chen, Lixin Zhang, Shuaishuai Niu, Junfeng Ren, Weijiang Gong, Xiangru Kong

专题命中 材料化学 :预测交变磁体中量子自旋霍尔效应,材料物理

AI总结 本文通过对称性分析,将量子自旋霍尔效应拓展至交变磁体,揭示了自旋-谷锁定或自旋-谷-层锁定机制,并利用第一性原理计算在单层Nb2SeTeO和双层Hf3Se3Te2中实现了交变磁量子自旋霍尔效应。

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AI中文摘要

量子自旋霍尔效应(QSHE)因其由非平凡拓扑不变量和螺旋边缘态保护的无耗散输运而受到广泛关注。由于即使是微弱的磁无序也能破坏拓扑量子态的稳定性,目前对QSHE的研究主要集中在非磁性材料上。在这项工作中,我们将QSHE的研究范围扩展到交变磁体。我们建立了相关的对称性约束,并识别了所有能够实现交变磁QSHE的磁点群。对称性分析表明,在这些系统中普遍存在显著的自旋-谷锁定或自旋-谷-层锁定。能带反转与自旋-谷锁定之间的协同相互作用共同产生了螺旋边缘态。利用第一性原理计算和理论模型,我们证明了单层Nb2SeTeO表现出具有自旋-谷锁定特征的交变磁QSHE,而双层Hf3Se3Te2则表现出具有自旋-谷-层锁定特征的交变磁QSHE。这项工作阐明了交变磁性与量子自旋霍尔拓扑相之间的内在对称性关联,为探索磁性拓扑系统和开发下一代自旋电子器件提供了全新的理论视角和研究平台。

英文摘要

The quantum spin Hall effect (QSHE) has attracted widespread attention due to its dissipationless transport, which is protected by non-trivial topological invariants and helical edge states. Because even weak magnetic disorder can destroy the stability of topological quantum states, current research on the QSHE has primarily focused on non-magnetic materials. In this work, we extend the research scope of the QSHE to altermagnets. We establish the relevant symmetry constraints and identify all magnetic point groups that can realize the altermagnetic QSHE. Symmetry analysis reveals that pronounced spin-valley locking or spin-valley-layer locking universally exists in these systems. The concerted interaction between band inversion and spin-valley locking collectively gives rise to the helical edge states. Using first-principles calculations and theoretical models, we demonstrate that monolayer Nb2SeTeO exhibits an altermagnetic QSHE characterized by spin-valley locking, while bilayer Hf3Se3Te2 manifests an altermagnetic QSHE featuring spin-valley-layer locking. This work clarifies the intrinsic symmetry correlation between altermagnetism and quantum spin Hall topological phases, providing a brand-new theoretical perspective and research platform for exploring magnetic topological systems and developing next-generation spintronic devices

2606.19780 2026-06-19 cond-mat.mtrl-sci 新提交 80%

Thickness-Dependent Interlayer Coupling and Semiconductor-to-Semimetal Crossover in Arsenene Multilayers

砷烯多层膜中层间耦合的厚度依赖性与半导体-半金属交叉

Jeonghwan Ahn, Seoung-Hun Kang, Jaron T. Krogel

专题命中 材料化学 :研究砷烯多层膜层间耦合,材料计算

AI总结 通过扩散量子蒙特卡洛和密度泛函理论计算,发现砷烯多层膜中层间耦合随厚度变化,导致从半导体到半金属的转变,并预测了堆叠序列的厚度驱动转变。

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AI中文摘要

层状材料中的层间相互作用通常被认为从双层到体相是传递的,但当化学活性的面外轨道参与成键时,这种假设可能失效。我们结合扩散量子蒙特卡洛(DMC)和密度泛函理论(DFT)来确定砷烯多层膜中层间耦合如何演变。DMC显示体相灰砷是紧密的,而相应的少层结构尽管共享相同的名义A$_{1}$B$_{-1}$相邻层注册表,但仍保持在显著更大的层间分离。因此,仅凭注册表并不能决定成键状态;厚度和配位重塑了层间相互作用。在测试的泛函中,SCAN+rVV10最接近地再现了DMC平衡分离和堆叠能量学。使用DMC基准化的SCAN+rVV10计算,我们预测了从A$_{1}$A$_{1}$到A$_{1}$B$_{1}$再到类体相A$_{1}$B$_{-1}$的厚度驱动堆叠序列。结构交叉与堆叠依赖的DFT带隙崩溃同时发生,该崩溃由增强的层间As p$_{z}$杂化驱动。

英文摘要

Interlayer interactions in layered materials are often assumed to transfer from the bilayer to the bulk, but this assumption can fail when chemically active out-of-plane orbitals participate in bonding. We combine diffusion quantum Monte Carlo (DMC) and density functional theory (DFT) to determine how interlayer coupling evolves in arsenene multilayers. DMC shows that bulk gray arsenic is compact, whereas the corresponding few-layer structures remain at substantially larger interlayer separations despite sharing the same nominal A$_{1}$B$_{-1}$ adjacent-layer registry. Registry alone therefore does not determine the bonding regime; thickness and coordination reshape the interlayer interaction. Among the tested functionals, SCAN+rVV10 most closely reproduces DMC equilibrium separations and stacking energetics. Using the DMC-benchmarked SCAN+rVV10 calculations, we predict a thickness-driven stacking sequence from A$_{1}$A$_{1}$ to A$_{1}$B$_{1}$ and finally bulk-like A$_{1}$B$_{-1}$. The structural crossover coincides with a stacking-dependent DFT band-gap collapse driven by enhanced interlayer As p$_{z}$ hybridization.

2606.19740 2026-06-19 cond-mat.mtrl-sci 新提交 80%

Enhanced electronic correlations and altermagnetic ground state of two-dimensional CsCr3Sb5 monolayers

二维CsCr3Sb5单层的增强电子关联和交变磁基态

Z. H. Guan, Z. L. Peng, W. Z. Zhuo, G. Tian, Z. P. Hou, D. Y. Chen, Z. Fan, X. B. Lu, X. S. Gao, M. H. Qin, J. M. Liu

专题命中 材料化学 :研究二维CsCr3Sb5电子关联,材料物理

AI总结 通过第一性原理计算,发现二维Cr3Sb5和CsCr3Sb5单层中平带和范霍夫奇点靠近费米能级,增强电子关联,且拉伸应变可进一步调控,同时揭示交变磁基态。

Comments 22 pages, 5 figures

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AI中文摘要

最近,层状修正的kagome金属CsCr3Sb5因其在费米能级(EF)附近的平带和交变磁基态而受到广泛关注[Yi Liu et al., Nature 632, 1032 (2024)]。然而,块体CsCr3Sb5中的范霍夫奇点(vHSs)远离EF,而有效调控vHS向EF靠近对于探索有趣的电子输运性质至关重要。在本工作中,利用第一性原理计算,我们研究了可能从块体材料机械剥离的二维(2D)Cr3Sb5和CsCr3Sb5单层的电子结构。值得注意的是,发现Cr3Sb5单层中平带和vHSs同时紧邻EF,表明增强的电子关联。重要的是,拉伸应变进一步将两个单层的初始平带和vHSs同时移至EF附近,表明应变可调谐的电子关联及伴随的量子效应。此外,由于这两个单层中两个子晶格之间保持镜面对称性,还揭示了交变磁基态。因此,本工作推进了对二维CsCr3Sb5单层电子性质的理解和调控,增强了它们在探索非常规量子现象和交变磁性方面的巨大潜力。

英文摘要

Recently, layered corrected kagome metal CsCr3Sb5 have garnered significant attention attributed to its flat bands near the Fermi level (EF) and altermagnetic ground state [ Yi Liu et al., Nature 632, 1032 (2024)]. However, the van Hove singularities (vHSs) in bulk CsCr3Sb5 are far away from the EF, while an effective modulation of VHS toward the EF is essential for exploring intriguing electron transport properties. In this work, using first-principles calculations, we investigate electronic structures of two-dimensional (2D) Cr3Sb5 and CsCr3Sb5 monolayers which may be mechanically exfoliated from bulk materials. Notably, it is revealed that both flat bands and vHSs simultaneously reside in close proximity to the EF in Cr3Sb5 monolayer, signifying enhanced electronic correlations. Importantly, a tensile strain further shifts the incipient flat bands and vHSs of two monolayers simultaneously to the vicinity of the EF, suggesting strain tunable electronic correlations and concomitant quantum effects. Furthermore, altermagnetic ground state is also revealed due to retained mirror symmetry between two sublattices in these two monolayers. Thus, this work advances understanding and modulations of electronic properties of 2D CsCr3Sb5 monolayers, strengthening their great potential for exploring unconventional quantum phenomena and altermagnetism.

2606.19571 2026-06-19 cond-mat.mes-hall cond-mat.mtrl-sci 新提交 80%

Optical spin injection in graphane and fluorographene

石墨烷和氟化石墨烯中的光学自旋注入

Angélica Marina López-Martínez, César Castillo-Quevedo, Cesar Camas-Flores, Analila Luna-Valenzuela, Jose Luis Cabellos

专题命中 材料化学 :石墨烷和氟化石墨烯光学自旋注入

AI总结 利用密度泛函理论研究石墨烷和氟化石墨烯不同构型的光学自旋注入响应,发现氟化石墨烯之字形构型在带边和宽光子能量范围内实现98%的自旋极化电子,而其他构型仅在有限能量范围内达到83-100%的自旋极化。

Comments 13 pages

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AI中文摘要

我们利用密度泛函理论,从理论上研究了石墨烷和氟化石墨烯不同化学计量构型中的光学自旋注入响应。我们的目标是确定哪种构型能产生最强的自旋极化度。结果表明,氟化石墨烯之字形构型产生了最佳的自旋极化响应(${\cal DSP}^{\mathrm{z}}$),在带边和宽激发光子能量范围内具有98%的自旋极化电子。相比之下,其他石墨烷和氟化石墨烯构型仅在有限的光子激发能量范围内达到约83-100%的${\cal DSP}^{\mathrm{z}}$。在自旋-轨道耦合较低的结构中,自旋极化度在宽光子能量范围内接近100%。对于较高的自旋-轨道耦合,这种强响应出现,但仅在窄光子能量区域内。此外,在能带分辨分解方案下,通过仅求和选定的价带和导带,识别了不同带间跃迁对${\cal DSP}^{\mathrm{z}}$谱的贡献。我们的发现表明,氟化石墨烯之字形构型的几乎整个${\cal DSP}^{\mathrm{z}}$谱来自仅涉及顶部价带的跃迁,该价带是C-p和F-p态的混合。

英文摘要

We theoretically investigate the optical spin-injection response in different stoichiometric configurations of graphane and fluorographene using density functional theory. Our goal is to determine which configuration yields the strongest degree of spin polarization. The results show that the fluorographene zigzag configuration yields the best degree of spin polarization response (${\cal DSP}^{\mathrm{z}}$), with 98\% spin polarized electrons at the band edge and over a wide range of excitation photon energies. In contrast, other graphane and fluorographene configurations achieve a ${\cal DSP}^{\mathrm{z}}$ of roughly 83--100\%, but only within a limited photon-excitation energy range. In structures with low spin-orbit coupling, the degree of spin polarization is close to 100\% over a wide range of photon energies. For higher spin-orbit coupling, this strong response appears, but only in a narrow photon energy region. Additionally, under the band-resolved decomposition scheme, the contributions of different band-to-band transitions to the ${\cal DSP}^{\mathrm{z}}$ spectrum are identified by summing only the selected valence and conduction bands. Our findings show that almost the entire ${\cal DSP}^{\mathrm{z}}$ spectrum of the fluorographene zigzag configuration comes from transitions that involve only the top valence band, which is a mixture of C--p and F--p states.

2606.19418 2026-06-19 cond-mat.soft physics.chem-ph 新提交 80%

Sequential replica exchange with solute tempering for atomistic modeling of supramolecular polymer structures

用于超分子聚合物结构原子建模的溶质调节顺序副本交换

Hadi H. Arefi, Takeshi Yamamoto

专题命中 材料化学 :超分子聚合物结构原子建模方法

AI总结 提出一种顺序副本交换与溶质调节方法,通过逐步添加单体并优化结合位置,高效构建一维超分子聚合物结构,降低计算成本并改善副本遍历效率。

Comments 13 pages, 9 figures

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AI中文摘要

预测自组装系统的详细原子结构仍然是全原子分子动力学模拟的挑战。溶质调节副本交换(REST)已被用于通过全局统一加速所有单体来研究这些系统。虽然这种全局方法原则上可以预测系统的任何形态,但它存在计算缺陷,例如由于有序-无序转变导致的副本遍历效率低下以及随系统规模增长的副本数量增加。为了解决这些问题,本文在一维聚合假设下,提出了一种替代的逐步构建方法来建模超分子聚合物。具体地,我们通过逐个向系统添加新单体并对其应用REST,基于能量评分函数找到其最佳结合位置,从而生成聚合物结构。重复单体添加和增强采样步骤,直到获得所需长度的聚合物。我们使用显式溶剂中的模型超分子聚合物测试了上述程序,结果表明,它能够以降低的计算成本生成具有特征氢键模式的聚合物结构,同时显著提高副本遍历效率。因此,我们预计顺序REST将有助于超分子聚合物的建模,特别是在全局REST模拟计算要求过高的情况下。

英文摘要

Predicting detailed atomistic structures of self-assembling systems remains a challenge for all-atom molecular dynamics simulations. Replica exchange with solute tempering (REST) has been used to study those systems by accelerating all monomers in a global and uniform manner. While such a global approach can in principle predict any morphology of the system, it has computational drawbacks such as inefficient replica traversal due to order-disorder transitions and the growing number of replicas with system size. To address these issues, here we propose an alternative, stepwise construction approach to modeling supramolecular polymers under the assumption of one-dimensional polymerization. Specifically, we generate polymer structures by adding new monomers one by one to the system and applying REST to the new monomers to find their optimal binding positions based on an energy-based scoring function. The monomer addition and enhanced sampling are repeated sequentially until a polymer of desired length is obtained. We test the above procedure using a model supramolecular polymer in explicit solvent, and show that it can generate a polymer structure with characteristic H-bonding patterns at reduced computational costs, while also improving the efficiency of replica traversal significantly. We thus expect that the sequential REST will be useful for modeling supramolecular polymers, particularly for cases where global REST simulations are too demanding computationally.

2. 物理仿真 17 篇

2606.19444 2026-06-19 cond-mat.quant-gas cond-mat.stat-mech cond-mat.str-el quant-ph 新提交 80%

Unleashing Emergent Fermions with Rydberg Atom Simulators

利用里德伯原子模拟器释放涌现费米子

Hanteng Wang, Xingyu Li, Shang Liu, Yingfei Gu, Chengshu Li

专题命中 物理仿真 :里德伯原子模拟器表征涌现费米子

AI总结 提出两种互补方法,在模拟和数字模式下利用里德伯原子模拟器的可重构性,通过莫比乌斯带几何实现反周期边界条件或量子电路实现基布尔-祖雷克扫描,以表征临界多体系统中的涌现费米子。

Comments 9 pages, 5 figures

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AI中文摘要

里德伯原子模拟器,无论是模拟模式还是数字模式,由于其灵活的几何可重构性,近年来引起了广泛关注。在这项工作中,利用这一特性,我们提出了两种互补的方法,每种模式各一种,用于表征临界量子多体系统中的涌现费米子。在模拟模式下,我们将里德伯原子组装成“可展”(即保持局域耦合)的莫比乌斯带几何,以实现反周期边界条件,费米子态存在于其中。对该扇区的光谱测量揭示了玻色子和费米子态的普适能量比。在数字模式下,我们用量子电路执行费米子版本的基布尔-祖雷克扫描,直接处理费米子标度形式。可重构性使得该任务呈指数级加速,电路深度开销为$O(\log L\log\log L)$。我们的工作确立了里德伯原子模拟器作为一个独特强大的平台,用于解决在玻色子系统中非局域定义的涌现费米子的实验探测这一公认难题。

英文摘要

Rydberg atom simulators, in both analog and digital modes, have attracted significant recent interest due to their versatile geometric reconfigurability. In this work, leveraging this feature, we propose two complementary approaches, one for each mode, to characterize emergent fermions in critical quantum many-body systems. In the analog mode, we assemble the Rydberg atoms in a "developable" (namely, preserving local couplings) Möbius band geometry to realize antiperiodic boundary conditions, where fermionic states reside. Spectroscopic measurement in this sector then reveals universal energy ratios of the bosonic and fermionic states. In the digital mode, we carry out a fermionic version of Kibble-Zurek ramping with a quantum circuit, directly addressing the fermionic scaling form. Reconfigurability allows an exponential speed-up of this task, with an $O(\log L\log\log L)$ circuit-depth overhead. Our work establishes the Rydberg atom simulator as a uniquely powerful platform to attack the notoriously difficult issue of experimentally probing emergent fermions that are nonlocally defined in a bosonic system.

2606.19437 2026-06-19 cond-mat.str-el cond-mat.stat-mech quant-ph 新提交 80%

Many-Body Protection of Topological Edge Memory in Strong Interacting Quenches

强相互作用淬火中拓扑边缘记忆的多体保护

Yuxiao Hang, Stephan Haas, Rishabh Jha

专题命中 物理仿真 :量子淬火中拓扑边缘记忆多体保护

AI总结 研究量子淬火后拓扑边缘态记忆在非可积相互作用系统中的存活,发现淬火后哈密顿量为相互作用时,边界模记忆通过多体保护机制在有限时间内稳定。

Comments 16+17 pages, 9+8 figures

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AI中文摘要

量子淬火驱动边缘态远离平衡,但拓扑初态的记忆是否能在非可积相互作用系统中存活,此前尚未充分探索。我们在键交替XXZ链(一种相互作用的Su-Schrieffer-Heeger模型,具有对称保护拓扑边缘模,边界磁化显著增强)中研究此问题,并分析所有单粒子和多体初态与末态哈密顿量组合的淬火。结果由单一区分组织,如我们在此工作中严格建立:淬火后哈密顿量是自由的还是真正相互作用的。对于自由淬火后哈密顿量,动力学通过关联矩阵方法精确求解;边界模返回振幅衰减为$t^{-3/2}$,初始相互作用仅通过缀饰的单体密度矩阵进入。对于真正相互作用的淬火后哈密顿量,有限时间稳定性界证明,远离局部共振时,第一二聚体磁化在时间窗口内保持稳定,该窗口可增长为逆二聚体间耦合的任意大幂次。所有四种协议下的矩阵乘积态模拟表明,最终哈密顿量中的相互作用显著延长了有限时间边界记忆——在各向同性$SU(2)$点附近局部抑制——揭示了一种非可积系统中的多体保护机制,否则混沌会迅速抹去初态记忆。

英文摘要

Quantum quenches drive edge states far from equilibrium, yet whether the memory of a topological initial state survives in a non-integrable, interacting system has remained largely unexplored. We study this question in the bond-alternating XXZ chain -- an interacting Su--Schrieffer--Heeger model hosting symmetry-protected topological edge modes with markedly enhanced boundary magnetization -- and analyze quenches across all combinations of single-particle and many-body initial and final Hamiltonians. The results organize by a single distinction as we rigorously establish in this work: whether the post-quench Hamiltonian is free or genuinely interacting. For a free post-quench Hamiltonian, the dynamics is solved exactly by a correlation-matrix approach; the boundary-mode return amplitude decays as $t^{-3/2}$, and initial interactions enter only through a dressed one-body density matrix. For a genuinely interacting post-quench Hamiltonian, finite-time stability bounds prove that away from local resonances the first-dimer magnetization remains stable on time windows growing as arbitrarily large powers of the inverse inter-dimer coupling. Matrix product state simulations across all four protocols show that interactions in the final Hamiltonian markedly extend finite-time boundary memory -- with local suppression near the isotropic $SU(2)$ point -- revealing a many-body protection mechanism in a non-integrable system where scrambling would otherwise wash out initial-state memory fast.

2606.19436 2026-06-19 cond-mat.dis-nn cond-mat.mes-hall cond-mat.other 新提交 80%

Observation of complete delocalization in disordered photonic lattices

无序光子晶格中完全去局域化的观测

Biplab Pal, Rodrigo A. Vicencio

专题命中 物理仿真 :无序光子晶格完全去局域化观测

AI总结 本文在完全无序的钻石点链中观察到安德森局域化的完全缺失和粒子的完美传输,通过几何条件产生的透明窗口证明了该现象,并通过数值模拟和飞秒激光写入的光子晶格实验验证,同时展示了π有效磁通下极端局域化的可能性。

Comments Main Text (5 pages, 4 figures); Supplemental Material (11 pages, 10 figures); Supplemental Material is added as an Ancillary file; Comments are welcome

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AI中文摘要

我们展示了在完全无序的钻石点链中,安德森局域化完全缺失以及粒子完美传输的异常现象。我们基于几何条件产生的透明窗口,解析地证明了观测到这一异常现象的条件。我们通过数值模拟和飞秒激光写入的钻石点光子晶格中光传输概率的直接实验观测,支持了我们的理论预测。我们还表明,对于π有效磁通,同一系统中可能发生光的极端局域化,而与具体几何结构无关。我们的结果为在完全无序的晶格系统中控制能量从弹道传输到零传输提供了一个极好的平台。

英文摘要

We present the exceptional phenomenon of complete absence of Anderson localization, and perfect transmission of particles, in a completely disordered diamond-dot chain. We analytically show a proof for the condition to observe this exceptional phenomenon, based on a transparent window emerging from a geometrical condition. We support our theoretical prediction by numerical simulations and direct experimental observation of the transmission probabilities of the light in a femtosecond laser-written diamond-dot photonic lattices. We additionally show that for a $π$ effective magnetic flux, extreme localization of the light in the same system may occur, independently on the specific geometry. Our results open up an excellent platform for controlling the transmission of energy from ballistic to zero transmission, in a completely disordered lattice system..

2606.19426 2026-06-19 cond-mat.str-el cond-mat.mes-hall 新提交 80%

Three-dimensional Foliated Fractional Quantum Hall Phases

三维分层分数量子霍尔相

Sahana Das, Navketan Batra, Andrea Kouta Dagnino, Dan Mao, Nicolas Regnault, Glenn Wagner, Titus Neupert

专题命中 物理仿真 :三维分层分数量子霍尔相研究

AI总结 研究三维分层系统中任意子层内自由运动但层间不可跳跃的拓扑序,发现解耦Laughlin态在层间相互作用下稳定,并可进入自发层三聚化的非阿贝尔Fibonacci相,通过数值和解析计算验证。

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AI中文摘要

三维中的分层拓扑序是分层系统,其中任意子可以在层内自由移动但不能在层间跳跃。具有这种相的简单模型是强磁场中解耦的二维电子气堆栈,每层处于相同的分数量子霍尔态。通过关注每层最低朗道能级填充$\nu=1/3$的情况,我们证明(i)解耦Laughlin态的极限在引入层间相互作用时是稳定的,以及(ii)系统可以进入自发层三聚化的分层非阿贝尔Fibonacci相。我们通过最多10层的数值精确对角化以及微扰解析计算支持我们的主张。具体地,我们展示了分层Fibonacci相存在于具有层内和相邻层间赝势相互作用的9层系统中。我们通过准空穴计数和与从相关共形场论导出的模型波函数的重叠来识别该相。我们的数值结果表明在强磁场中的分层范德华晶体以及多层异质结构中实现这些相的可能性。

英文摘要

Foliated topological orders in three dimensions are layered systems in which anyons are free to move within a layer but cannot hop between them. A simple model with such a phase is a stack of decoupled two-dimensional electron gases in a strong magnetic field, each in the same fractional quantum Hall state. By focusing on the case of filling $ν=1/3$ of the lowest Landau level in each layer, we show that (i) the limit of decoupled Laughlin states is stable upon introducing interlayer interactions and (ii) the system can enter a spontaneously layer-trimerized foliated non-Abelian Fibonacci phase. We support our claims by numerical exact diagonalization of up to 10 layers as well as perturbative analytical calculations. Specifically, we show that the foliated Fibonacci phase exists in the 9-layer system with pseudopotential interactions within and between neighboring layers. We identify the phase via quasihole counting and by calculating the overlap with a model wave function which we derive from the associated conformal field theory. Our numerical results suggest the possibility of realizing these phases in layered van der Waals crystals in strong magnetic fields, as well as in multilayer heterostructures.

2606.16932 2026-06-19 quant-ph physics.optics 新提交 80%

Experimental quantum state learning with pairs of photons

利用光子对进行实验量子态学习

C. Pria Dobney, Johan Henaff, Allen Kasum, Rui Jie Tang, Haru Mukumoto, Mark Hillery, Berthold-Georg Englert, Aephraim Steinberg

专题命中 物理仿真 :实验实现光子对量子态学习协议

AI总结 本文通过光子对实验实现了Agarwal等人提出的量子态学习协议,能够从成对光子中推断出纯态成分及其权重,并区分不同混合态。

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AI中文摘要

层析成像允许人们估计描述量子系统 ensemble 制备状态的密度矩阵(例如,偏振层析成像确定一束相同制备光子的偏振态)。通常,不可能将密度矩阵唯一分解为其纯态分量。Agarwal等人提出了一种协议,对于由任意两个纯态(以任意概率)组成的混合态,观察者不仅可以推断出密度矩阵,还可以推断出这些特定纯态的身份及其权重——额外要求是量子比特成对到达,每对中的两个量子比特处于相同状态。我们利用光子的偏振自由度实验演示了这种“从对中学习”的概念。我们使用层析成像测量一系列单光子,并利用它们的到达时间信息在测量后“配对”光子。由此,我们能够推断出光子的偏振态及其各自的概率,并针对不同的偏振态和比例进行了演示。最后,我们研究了区分两个由不同正交偏振态对组成的等概率混合态的能力。我们发现,大约10^4个光子通常足以实现约0.9999的层析成像保真度。这足以区分同一混合态的两种不同制备,这两种制备中使用的纯态之间的角度差小于5度。

英文摘要

Tomography allows one to estimate the density matrix describing the state an ensemble of quantum systems are prepared in (for example, polarization tomography determines the polarization state of a beam of identically prepared photons). In general, it is not possible to uniquely decompose the density matrix into its pure state components. Agarwal et al. proposed a protocol which, for a mixture composed of any two pure states of a qubit (with arbitrary probabilities), allows an observer to infer not only the density matrix but the identity of those specific pure states and their weights - the additional requirement being that the qubits arrive in pairs, where both qubits in each pair are in the same state. We experimentally demonstrate this learning-from-pairs concept using photons in the polarization degree of freedom. We use tomography to measure a sequence of single photons and make use of their time-of-arrival information to 'pair up' the photons after the measurement. From here we are able to infer the photons' polarization states and their respective probabilities, and we demonstrate this for various different choices of polarization states and ratios. Finally, we investigate our ability to discriminate between two equal mixtures of distinct pairs of orthogonal polarization states. We find that on the order of approx. 10e4 photons is typically enough to achieve tomography fidelities of approximately 0.9999. This is sufficient to discriminate between two different preparations of the same mixed state, differing by angles of less than 5 degrees between the pure states used in the two preparations.

2606.15657 2026-06-19 math.AP 新提交 80%

Semi-wave and sharp estimates of propagation for monostable free boundary problems in time-periodic environment

时间周期环境下单稳自由边界问题的半波及传播的精确估计

Yihong Du, Zhuo Ma

专题命中 物理仿真 :研究自由边界问题的传播轮廓,属于物理仿真

AI总结 研究时间周期单稳自由边界问题中正解的传播轮廓,通过证明半波的存在唯一性及解收敛到半波,将结果从KPP条件推广到一般单稳非线性。

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AI中文摘要

我们研究以下方程的正解的传播轮廓:\n\begin{equation*}\nu_t-du_{xx}=f(t,u) \mbox{ for } t>0,\\ x\in(g(t),h(t)),\n\end{equation*}\n其中 $f(t,u)$ 关于 $u$ 是单稳的且关于 $t$ 是 $T$-周期的,自由边界 $x=g(t),\\ x=h(t)$ 由 Stefan 条件 $g'(t)=-\mu u_x(t, g(t)),\\ h'(t)=-\mu u_x(t,h(t))$ 决定,并满足 $u(t, g(t))=u(t, h(t))=0$。对于满足强 KPP 条件的特殊非线性,Du、Guo 和 Peng \cite{DGP} 考虑了该问题的长时间行为和渐近传播速度。在本文中,通过采用新技术,我们将 \cite{DGP} 的结果推广到 KPP 框架之外的一般单稳非线性,同时获得了传播轮廓的更精确描述:我们证明了半波的存在唯一性,并表明当时间趋于无穷时,传播解收敛到该半波。

英文摘要

We investigate the propagation profile of positive solutions to \begin{equation*} u_t-du_{xx}=f(t,u) \mbox{ for } t>0,\ x\in(g(t),h(t)), \end{equation*} where $f(t,u)$ is monostable in $u$ and $T$-periodic in $t$, and the free boundaries $x=g(t), \ x=h(t)$ are determined by the Stefan condition $g'(t)=-μu_x(t, g(t)),\ h'(t)=-μu_x(t,h(t))$, coupled with $u(t, g(t))=u(t, h(t))=0$. For a special nonlinearity satisfying the strong KPP condition, the long-time behavior and asymptotic spreading speed of this problem were considered by Du, Guo and Peng \cite{DGP}. In this paper, by employing new techniques, we extend the results of \cite{DGP} to general monostable nonlinearities beyond the KPP framework and at the same time we obtain more precise description of the propagation profile: we prove the existence and uniqueness of a semi-wave and show that the spreading solution converges to this semi-wave as time goes to infinity.

2606.10266 2026-06-19 quant-ph math-ph math.MP 新提交 80%

The Quantum Transition State

量子力学中无再交叉分割面

Pouya Khazaei

专题命中 物理仿真 :量子力学中过渡态几何的数学物理研究

AI总结 本文证明量子流可存在稳定与不稳定不变流形,其交线定义唯一有界轨迹,锚定一个移动分割面,使量子特征线恰好穿过一次,产生标准量子概率流的单向通量,从而将经典反应动力学的几何框架推广到量子情形。

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AI中文摘要

近一个世纪以来,量子力学中无再交叉分割面一直被认为是不可能的。单向反应通量似乎需要同时具备位置和动量的轨迹级知识——这与不确定性原理明显冲突。我们表明这一障碍并非根本性的。精确量子流可以存在稳定和不稳定不变流形,它们的交线定义了一个唯一的有界轨迹。该轨迹锚定了一个移动的分割面,反应量子特征线恰好穿过该面一次,产生标准量子概率流的单向通量。因此,经典反应动力学背后的几何框架以根本性的量子形式延续到了精确量子流中。

英文摘要

For nearly a century, the transition state has been thought to lack an exact quantum counterpart: recrossing-free, one-way flux seems to require simultaneous knowledge of position and momentum. We show that this obstruction is illusory. The exact quantum flow contains a transition-state geometry: stable and unstable manifolds meeting in a unique bounded quantum transition-state trajectory that anchors a dividing surface carrying one-way quantum probability flux. The geometric framework of classical reaction dynamics survives in exact quantum mechanics, in a fundamentally quantum form.

2606.07250 2026-06-19 physics.acc-ph 新提交 80%

Expanding LUME to Support Virtual Accelerators and Digital Twins

扩展 LUME 以支持虚拟加速器和数字孪生

Ryan Roussel, Christopher M. Pierce, Sara Miskovich, Gopika Bhardwaj, Jeremy Lorelli, Ken Lauer, Auralee Edelen, Christopher Mayes

专题命中 物理仿真 :虚拟加速器与数字孪生框架,加速器物理

AI总结 本文扩展 LUME Python 包,通过引入 LUMEModel 抽象和变量系统,实现跨异构仿真后端和控制系统的虚拟加速器与数字孪生的标准化部署,提升可重用性和灵活性。

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AI中文摘要

虚拟加速器和数字孪生正日益成为加速器运行、控制开发与验证以及基于模型优化的关键工具。然而,当前的实现通常与特定的仿真代码、设施和应用紧密耦合,导致碎片化、临时性的解决方案难以重用或扩展。为解决这一问题,我们扩展了 LUME Python 包,使其能够跨异构仿真后端和控制系统接口实现虚拟加速器和数字孪生的标准化部署与实现。这一变化的核心是引入了 LUMEModel 抽象,它定义了一个固定的、与模拟器无关的 API 和一个变量系统,用于编码元数据,如单位、数据类型/验证。该设计支持与基于物理的模拟器、代理模型和可微分仿真的标准化交互,同时通过 lume-pva 包支持 Python 原生工作流和基于 EPICS 的 IOC 操作。设施和模拟器特定的细节通过可扩展的转换器层封装,从而将一致的控制系统语义映射到不同的仿真引擎上。我们描述了 LUMEModel 架构、变量系统和包生态系统,并展示了代表性用例,包括模型互换性、分阶段和链式模拟器以及持续集成测试。这项工作将使虚拟加速器的实现和使用更加容易和灵活。

英文摘要

Virtual accelerators and digital twins are increasingly essential tools for accelerator operations, controls development and verification, and model-based optimization. However, current implementations are often tightly coupled to specific simulation codes, facilities, and applications, resulting in fragmented, ad hoc solutions that are difficult to reuse or extend. To address this, we expand the LUME Python package to include standardized implementation and deployment of virtual accelerators and digital twins across heterogeneous simulation backends and control system interfaces. At the core of this change is the introduction of LUMEModel abstraction, which defines a fixed, simulator-agnostic API and a variable system that encodes metadata such as units and data types/validation. This design enables standardized interaction with physics-based simulators, surrogate models, and differentiable simulations, while supporting both Python-native workflows and IOC-based operation via EPICS using the lume-pva package. Facility- and simulator-specific details are encapsulated through extensible transformer layers, allowing consistent control-system semantics to be mapped onto diverse simulation engines. We describe the LUMEModel architecture, variable system, and package ecosystem, and present representative use cases including model interchangeability, staged and chained simulators, and continuous integration testing. This work will make implementing and using virtual accelerators easier and more flexible.

2606.01295 2026-06-19 astro-ph.IM physics.ins-det 80%

PSF-like Alpha-Particle Events in LSST Images

LSST图像中类似PSF的α粒子事件

Guillem Megias Homar, Craig S. Lage, Pierre-François Léget, Steven M. Kahn, Christopher W. Stubbs, S. R. Kulkarni, Ian S. Sullivan, James F. Bosch, Eli S. Rykoff

专题命中 物理仿真 :研究LSST图像中α粒子事件,属于天体物理。

AI总结 本文研究了LSST图像中由α粒子诱导的、类似PSF的电荷簇事件,通过四阶矩统计量将其与恒星PSF区分,并证明其对瞬变搜索无本质污染。

Comments 7 pages, 4 figures

Journal ref PASP 138 6 (2026) 064506

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AI中文摘要

罕见的α粒子诱导的电荷簇出现在LSST图像中,表现为紧凑的、类似PSF的点源,中值半高全宽为$0.\!\!^{\prime\prime}95$,中值椭圆率接近零,与未分辨的天体点源非常相似。这些事件在暗场和科学曝光中均被探测到,速率约为$10^{-12}\ \mathrm{pixel}^{-1}\ \mathrm{s}^{-1}$。它们的收集电荷和形态与硅CCD中约5 MeV α粒子的能量沉积一致,其在焦平面上的空间分布表明存在局部材料来源,可能与低温恒温器铝中的痕量放射性污染有关。尽管外观具有欺骗性,但我们证明,基于四阶矩的简单展宽统计量可以清晰地将这些事件与恒星PSF分离,从而在叠加图像和实时警报流中实现有效剔除。此类电荷簇不会对Rubin瞬变搜索造成固有的亮端污染下限,因为真正的快速天体事件会表现出特征不同的形态特征。

英文摘要

Rare $α$-particle-induced charge clusters appear in LSST images as compact, PSF-like sources with a median FWHM of $0.\!\!^{\prime\prime}95$ and median ellipticity consistent with zero, closely resembling unresolved astrophysical point sources. These events are detected in both dark and science exposures at a rate of approximately $10^{-12}\ \mathrm{pixel}^{-1}\ \mathrm{s}^{-1}$. Their collected charge and morphology are consistent with energy deposition from $\sim$5 MeV $α$-particles in silicon CCDs, and their spatial distribution across the focal plane suggests a localized material origin, plausibly associated with trace radioactive contamination in the cryostat aluminum. Despite their deceptive appearance, we demonstrate that a simple broadness statistic based on fourth-order moments cleanly separates these events from stellar PSFs, enabling efficient rejection in coadded images and real-time alert streams. Such charge clusters do not impose an intrinsic bright-end contamination floor for Rubin transient searches, as genuine fast astrophysical events would exhibit characteristically different morphological signatures.

2602.20322 2026-06-19 cond-mat.quant-gas quant-ph 80%

Equilibrium and dynamical quantum phase transitions in dipolar atomic Josephson junctions

双井势中极子原子约瑟夫森结中的平衡与动态量子相变

Cesare Vianello, Giovanni Mazzarella, Luca Salasnich

专题命中 物理仿真 :极子原子约瑟夫森结量子相变

AI总结 研究极子原子约瑟夫森结中平衡和动态量子相变的特性,通过均场理论和精确对角化分析相关过程对零温平衡和动态性质的影响,揭示了对NOON和相NOON态量子相变的质变影响以及临界点的量变变化。

Comments 18 pages, 9 figures

Journal ref Phys. Rev. A 113, 063318 (2026)

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AI中文摘要

利用双井势中极子玻色子实现的原子约瑟夫森结可以由扩展的玻色-哈伯德模型描述,其中极子相互作用产生有效的局域相互作用和最近邻对隧穿。通过均场理论和精确对角化,我们研究这种相关过程如何影响系统的零温平衡和动态性质。在平衡状态下,我们证明对隧穿诱导基态奇偶性调制,并显著重塑相图,产生向NOON和相NOON态的量子相变的质变变化,以及临界点的量变变化。在非平衡状态下,我们证明其修改了宏观量子自囚禁的条件,并通过比较均场和全量子演化的结果,评估其影响,包括动态量子相变的出现。

英文摘要

An atomic Josephson junction realized with dipolar bosons in a double-well potential can be described by an extended Bose-Hubbard model in which dipolar interactions generate an effective on-site interaction and nearest-neighbor pair tunneling. Using mean-field theory and exact diagonalization, we investigate how this correlated process affects zero-temperature equilibrium and dynamical properties of the system. In equilibrium, we show that pair tunneling induces ground-state parity modulations and significantly reshapes the phase diagram, producing qualitative changes in the quantum phase transitions toward NOON and phase-NOON states, as well as quantitative shifts of the critical points. Out of equilibrium, we demonstrate that it modifies the conditions for macroscopic quantum self-trapping, and assess its impact by comparing mean-field and fully quantum evolution, including the emergence of dynamical quantum phase transitions.

2605.21597 2026-06-19 quant-ph cond-mat.str-el 版本更新 80%

Matrix Product Operator Encodings of the Magnus Expansion and Dyson Series

矩阵积算符对Magnus展开式和Dyson级数的编码

Victor Vanthilt, Maarten Van Damme, Jutho Haegeman, Ian P. McCulloch, Laurens Vanderstraeten

专题命中 物理仿真 :矩阵积算符编码用于量子模拟

AI总结 本文提出了一种用于一维量子晶格模型中时间依赖哈密顿量的矩阵积算符(MPO)编码方法,能够高精度表示Magnus展开式和Dyson级数,适用于有限和无限系统及长程相互作用,并结合最先进的矩阵积态时间演化算法,显著提升时间依赖哈密顿量模拟效率,同时可用于量子电路优化。

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AI中文摘要

我们介绍了一种用于一维量子晶格模型中时间依赖哈密顿量的矩阵积算符(MPO)编码方法,用于Magnus展开式和Dyson级数。MPO构造可以任意高精度地在时间步长的任意阶数下进行,适用于有限和无限系统,并能处理长程相互作用。所得到的MPO可以与基于矩阵积态的最新时间演化算法相结合,从而在模拟时间依赖哈密顿量下的演化时取得显著改进。此外,我们的MPO构造还可用于时间依赖哈密顿量量子模拟中的量子电路优化。

英文摘要

We introduce a matrix product operator (MPO) encoding of the Magnus expansion and the Dyson series for one-dimensional quantum lattice models with time-dependent Hamiltonians. The MPO construction can be made accurate up to arbitrary order in the time step, it can be applied to both finite and infinite systems, and it can handle long-range interactions. The resulting MPO can be combined with state-of-the-art time evolution algorithms based on matrix product states, allowing for drastic improvements in simulating evolution under time-dependent Hamiltonians. Our MPO construction can also be used for the optimization of quantum circuits in the context of quantum simulation of time-dependent Hamiltonians.

2504.15501 2026-06-19 quant-ph cond-mat.mes-hall physics.chem-ph physics.optics 版本更新 80%

Mapping molecular polariton transport via pump-probe microscopy

通过泵-探测显微镜映射分子极子输运

Piper Fowler-Wright, Michael Reitz, Joel Yuen-Zhou

专题命中 物理仿真 :分子极子输运泵-探测显微镜研究

AI总结 本文通过泵-探测显微镜研究分子极子输运特性,结合微正则处理和扰动展开,揭示了极子输运与分子退相干和暗激发态人口的关系。

Comments 7+12 pages, 4+9 figures. Includes supplementary movie file showing pump-probe dynamics. [v3] close to published version, [v4] fixed wrong SI title

Journal ref Nano Lett. 2026, 26, 19, 6334-6340

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AI中文摘要

我们展示了如何通过泵-探测光谱的微观建模来提取光学腔中分子极子输运性质。我们的方法结合了光-物质哈密顿量的平均场处理,以及光和物质组分的微扰展开,以及空间粗粒化。该方法将 semiclassical 镜厅光谱学扩展到多模光-物质相互作用,提供了空间分辨的瞬态光谱的完整访问。通过模拟具有反向传播泵和探测脉冲的显微镜实验,我们计算了差分传输,并展示了分子退相干和持久暗激发子人口如何驱动根均方位移的亚子组速度输运。我们分析了极子色散跨运输,显示速度重整化与激发子权重的相关性,与实验观测一致,并进一步揭示其依赖于分子退相干速率。我们的结果强调了在极子系统中表征输运时考虑测量光谱观测变量的必要性。

英文摘要

We demonstrate how the transport properties of molecular polaritons in optical cavities can be extracted from a microscopic modeling of pump-probe spectroscopy. Our approach combines a mean-field treatment of the light-matter Hamiltonian with a perturbative expansion of both light and matter components, along with spatial coarse-graining. This approach extends semiclassical cavity spectroscopy to multimode light-matter interactions, providing full access to spatially resolved transient spectra. By simulating a microscopy experiment with counter-propagating pump and probe pulses, we compute the differential transmission and show how molecular dephasing and persistent dark exciton populations drive sub-group-velocity transport of the root-mean-square displacement. We analyze transport across the polariton dispersion, showing how velocity renormalization correlates with excitonic weight, consistent with experimental observations, and further its dependence on the rate of molecular dephasing. Our results highlight the need to consider measured spectroscopic observables when characterizing transport in polaritonic systems.

2403.12779 2026-06-19 cond-mat.str-el 80%

Quantum Fisher information in a strange metal

非常规金属中的量子 Fisher 信息

Federico Mazza, Sounak Biswas, Xinlin Yan, Andrey Prokofiev, Paul Steffens, Qimiao Si, Fakher F. Assaad, Silke Paschen

专题命中 物理仿真 :量子Fisher信息在非常规金属中的应用

AI总结 研究量子 Fisher 信息在非常规金属中的应用,通过中子散射和量子蒙特卡罗模拟探讨Kondo破坏量子临界点,发现远离磁布里格斯峰时量子 Fisher 信息增强,揭示其非寻常纠缠特性。

Comments 17 pages, 4 figures

Journal ref Nature Physics 2026

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AI中文摘要

非常规金属是一种关联量子物质的奇特状态;目前正致力于揭示其本质。本文探讨量子 Fisher 信息(QFI),量子计量学中的概念,是否能提供新见解。我们利用非弹性中子散射和量子蒙特卡罗模拟研究Kondo破坏量子临界点,其中非常规金属性与超越Landau序参量的涨落相关。我们发现,在远离磁布里格斯峰、磁序效应最小的区域,随着温度降低形成非常规金属时,QFI显著增强,无特征尺度,证明其非寻常纠缠特性。本文工作为跨非常规金属平台的研究开辟了新方向。

英文摘要

A strange metal is an exotic state of correlated quantum matter; intensive efforts are ongoing to decipher its nature. Here we explore whether the quantum Fisher information (QFI), a concept from quantum metrology, can provide new insight. We use inelastic neutron scattering and quantum Monte Carlo simulations to study a Kondo destruction quantum critical point, where strange metallicity is associated with fluctuations beyond a Landau order parameter. We find that the QFI probed away from magnetic Bragg peaks, where the effect of magnetic ordering is minimized, increases strongly and without a characteristic scale as the strange metal forms with decreasing temperature, evidencing its unusual entanglement properties. Our work opens a new direction for studies across strange metal platforms.

2604.08193 2026-06-19 hep-ph astro-ph.CO astro-ph.IM physics.ins-det physics.optics 版本更新 80%

Probing Majoron Dark Matter with Gravitational Wave Detectors

利用引力波探测器探测马约拉子暗物质

Ippei Obata, Tsutomu T. Yanagida

专题命中 物理仿真 :引力波探测器探测马约拉子暗物质

AI总结 研究通过线性光学腔探测马约拉子暗物质与光子的QED反常耦合导致的振荡双折射,利用地面激光干涉仪如Advanced LIGO、KAGRA等探测参数空间。

Comments 10 pages, 3 figures

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AI中文摘要

马约拉子是一种假设的(赝)南部-戈德斯通玻色子,源于全局轻子数对称性的自发破缺,被认为是宇宙中暗物质的候选者。在本文中,我们研究了利用干涉式引力波探测器中使用的线性光学腔探测马约拉子暗物质的可能性。我们考虑一种场景,其中马约拉子暗物质通过QED反常与光子耦合,导致由相干暗物质背景诱导的振荡光子双折射。反常系数通过要求模型同时再现电弱希格斯尺度和典型的右手中微子质量尺度来确定,由此产生的暗物质-光子耦合自然落在光学干涉仪的灵敏度范围内。通过加入额外的光学元件来提取双折射信号,我们发现地面激光干涉仪如Advanced LIGO、KAGRA以及未来的探测器,可以探测马约拉子暗物质的参数空间区域。

英文摘要

The Majoron is a hypothetical (pseudo) Nambu-Goldstone boson arising from the spontaneous breaking of a global lepton number symmetry, and is known as a candidate for dark matter in our Universe. In this paper, we investigate the possibility of probing the Majoron dark matter with a linear optical cavity used in the interferometric gravitational wave detectors. We consider a scenario in which the Majoron dark matter couples to photons through a QED anomaly, leading to an oscillatory photon birefringence induced by the coherent dark matter background. The anomaly coefficient is fixed by requiring the model to simultaneously reproduce the electroweak Higgs scale and a typical right-handed Majorana neutrino mass scale, and the resulting dark matter-photon coupling naturally falls within the sensitivity range of optical interferometers. By incorporating additional optics to extract the birefringence signal, we find that ground-based laser interferometers such as Advanced LIGO, KAGRA, as well as future detectors, can probe a region of the parameter space of Majoron dark matter.

2603.25949 2026-06-19 physics.plasm-ph astro-ph.HE 版本更新 80%

General-relativistic and non-ideal radiative cooling in neutron star magnetospheres

中子星磁层中的广义相对论与非理想辐射冷却

João Joaquim, Francisco Assunção, Pablo J. Bilbao, Luis O. Silva

专题命中 物理仿真 :研究中子星磁层辐射冷却,天体物理

AI总结 研究辐射反冲冷却在中子星磁层中的效应,发现非均匀电磁场和广义相对论增强相空间动力学不稳定性,有利于相干辐射发射。

Comments 12 pages, 5 figures

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AI中文摘要

辐射反冲冷却在描述天体物理致密天体磁层中的极端等离子体条件中起着重要作用。这些环境特有的强电磁场可以触发各向异性环状等离子体分布的发展,在动量空间中具有反转的朗道分布。在这项工作中,我们通过考虑非均匀电磁场几何和广义相对论效应如何修改辐射冷却等离子体的相空间动力学,首次系统地研究了这种机制在实际天体物理配置中的表现。我们解析地证明,漂移速度有利于形成仍然显示反转朗道分布的螺旋形动量分布,并估计了反转动量分布通过动力学不稳定性驱动相干辐射发射所需的最小和最大等离子体注入距离。通过数值模拟,我们得出结论:弯曲时空增加了负责动力学不稳定性发展的分布函数的梯度,并相对于平直时空延长了反转动量结构的持久性,证实了实际天体物理条件保留并增强了同步辐射驱动的相干辐射发射所需的条件。

英文摘要

Radiation reaction cooling plays an important role in describing the extreme plasma conditions found in the magnetospheres of astrophysical compact objects. Strong electromagnetic fields, characteristic of these environments, can trigger the development of anisotropic ring-shaped plasma distributions with inverted Landau populations in momentum space. In this work, we present the first systematic investigation of this mechanism in realistic astrophysical configurations, by accounting for how non-uniform electromagnetic field geometries and general-relativistic effects modify the phase-space dynamics of radiatively cooled plasmas. We demonstrate analytically that drift velocities favour the formation of spiral-shaped momentum distributions that still display inverted Landau populations, and estimate the minimum and maximum plasma injection distances required for inverted momentum distributions to be able to power the emission of coherent radiation through kinetic instabilities. From numerical simulations, we conclude that curved spacetime increases the gradient of the distribution function responsible for the development of kinetic instabilities, and prolongs the persistence of the inverted momentum structure relative to flat spacetime, confirming that realistic astrophysical conditions preserve and enhance the conditions necessary for synchrotron-powered emission of coherent radiation to occur.

2603.23021 2026-06-19 cond-mat.stat-mech 版本更新 80%

Dynamics of Aligning Active Matter: Mapping to a Schrödinger Equation and Exact Diagonalization

对齐活性物质的动力学:映射到薛定谔方程与精确对角化

Tara Steinhöfel, Horst-Holger Boltz, Thomas Ihle

专题命中 物理仿真 :活性物质动力学映射到薛定谔方程

AI总结 通过将Fokker-Planck方程映射到薛定谔方程并进行精确对角化,严格分析了小尺度全连接对齐自推进粒子的弛豫模式,改进了线性化统计场论的近似结果,并扩展到非互易相互作用情形。

Journal ref Eur. Phys. J. Spec. Top.(2026)

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AI中文摘要

最近,小尺度全连接对齐自推进粒子系统的弛豫模式引起了关注(Spera等人,Phys. Rev. Lett. {\bf 132}: 078301 (2024))。我们重新审视Fokker-Planck方程与薛定谔方程之间的经典联系,通过精确对角化来处理这一问题,从而对全谱进行严格的分析洞察。这使我们能够提取精确结果,并与线性化统计场论的现有结果进行比较。我们推导出渐近正确的解析结果,改进了先前的近似。我们表明,该方法可以有效地扩展到非互易相互作用的情形,这导致了类似于开放量子力学中的非厄米薛定谔问题。虽然非互易性可以选择为不改变稳态分布,但它从根本上改变了稳态的性质,我们通过熵产生来量化这一点。我们讨论了低粒子数的情况以及大粒子数时平均场动力学的出现。

英文摘要

There has been recent interest in the relaxational modes of small-scale fully connected systems of aligning self-propelled particles (Spera et al., Phys. Rev. Lett. {\bf 132}: 078301 (2024)). We revisit the classical connection between Fokker-Planck and Schrödinger equations to address this by means of exact diagonalization, allowing for rigorous analytical insight into the full spectrum. This allows us to extract exact results which we compare to the existing result from linearized statistical field theory. We derive asymptotically correct analytical results that improve upon the prior approximations. We show that this methodology can fruitfully be extended to the case of non-reciprocal interactions which gives rise to a non-Hermitian Schrödinger problem akin to those in open quantum mechanics. While the non-reciprocity can be chosen such as not to alter the stationary distribution, it fundamentally changes the nature of the steady state which we quantify via the entropy production. We discuss the case of low particle numbers as well as the emergence of mean-field dynamics at large numbers.

2603.04143 2026-06-19 cond-mat.mes-hall 版本更新 80%

Constructing Exceptional Knots and Links with Arbitrary Braiding Topology

构造具有任意编织拓扑的例外纽结与链环

Bin Jiang, Aolong Guo, Qilin Cai, Jian-Hua Jiang

专题命中 物理仿真 :构造非厄米系统中例外纽结,凝聚态物理。

AI总结 提出基于辫理论与半全纯多项式的通用框架,在三维两带非厄米系统中实现任意编织拓扑的例外纽结与链环,并展示可控拓扑转变。

Comments Commemts are welcome

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AI中文摘要

例外纽结和链环代表了一类显著的非厄米金属,其中例外简并在动量空间中形成纽结或链环流形。在此,我们报告了一个通用构造框架,用于在三维最小两带非厄米系统中实现具有任意编织拓扑的例外纽结和链环。我们的方法结合了辫理论与半全纯多项式,建立了辫词与非厄米布洛赫哈密顿量之间的直接对应关系。该框架能够在显式紧束缚哈密顿量中实现多种例外构型,包括环面纽结、双纽线纽结、非纤维纽结、双曲纽结和多分量链环。此外,我们展示了可控拓扑转变,其中例外纽结可以通过例外点的重新分布和重新连接连续解开,伴随瞬态例外链和谱复能量编织的变化。我们的结果为可编程非厄米纽结拓扑建立了一条通用途径,并为在光子、声学、力学和冷原子系统中探索纽结能带简并及其相关物理现象提供了一个多功能平台。

英文摘要

Exceptional knots and links represent a remarkable class of non-Hermitian metals in which exceptional degeneracies form knotted or linked manifolds in momentum space. Here, we report a universal construction framework for realizing exceptional knots and links with arbitrary braiding topology in 3D minimal two-band non-Hermitian systems. Our approach combines braid theory with semiholomorphic polynomials to establish a direct correspondence between braid words and non-Hermitian Bloch Hamiltonians. This framework enables the realization of a broad variety of exceptional configurations, including torus knots, lemniscate knots, nonfibred knots, hyperbolic knots, and multi-component links, within explicit tight-binding Hamiltonians. Furthermore, we demonstrate controllable topological transitions in which exceptional knots can be continuously untied through redistribution and reconnection of exceptional points, accompanied by transient exceptional chains and changes in spectral complex energy braiding. Our results establish a universal route toward programmable non-Hermitian knot topology and provide a versatile platform for exploring knotted band degeneracies and their associated physical phenomena across photonic, acoustic, mechanical, and cold-atom systems.

3. 其他科学智能 8 篇

2606.16803 2026-06-19 q-bio.MN q-bio.SC 新提交 80%

Cell Division Changes Fate Decisions in a Genetic Toggle Switch

细胞分裂改变遗传开关中的命运决定

Charli Austin, Nikola Popovic, Ramon Grima

专题命中 其他科学智能 :研究细胞分裂对遗传开关命运的影响

AI总结 本研究通过分析布尔型遗传开关模型,发现细胞分裂可将相同初始条件的轨迹导向不同稳定态,并定义了忽略分裂时命运预测错误的区域,表明分裂可重塑多稳态调控网络的命运边界。

Comments 16 pages;7 figures. Includes new Figure A.2 comparing the separatrices of the classical and Boolean toggle switches, with and without cell division. Two Appendices (previously H and I in the previous version) integrated into Appendix E for clarity

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AI中文摘要

基因调控网络通过多稳态动力学控制细胞命运决定。遗传开关是此类行为的经典模型;然而,细胞分裂对其动力学的影响仍知之甚少。我们推导了有无分裂的简化布尔型开关的解析分界线。我们证明,分裂可以将具有相同初始条件的轨迹重定向到相反的稳定态,并定义了一个不一致区域,在该区域中,如果忽略分裂,则命运预测错误。我们的结果表明,分裂可以从根本上重塑多稳态调控网络中的命运边界。

英文摘要

Gene regulatory networks govern cellular fate decisions through multistable dynamics. The genetic toggle switch is a canonical model of such behaviour; yet, the impact of cell division on its dynamics remains poorly understood. We derive analytical separatrices for a simplified Boolean toggle switch with and without division. We show that division can redirect trajectories with identical initial conditions to opposing stable states, and we define a region of disagreement where fate decisions are predicted incorrectly if division is neglected. Our results imply that division can fundamentally reshape fate boundaries in multistable regulatory networks.

2606.12660 2026-06-19 math.NT math.AC math.GR 新提交 80%

Root Clusters and Multiclusters over Imperfect Hilbertian Fields

根簇与多簇在不完美希尔伯特域上的推广

Shubham Jaiswal

专题命中 其他科学智能 :将根簇理论推广到一般域,属于数学理论扩展

AI总结 将根簇理论从完美域推广到一般域,引入根簇大小、多簇大小等概念,并在希尔伯特域上建立了这些广义概念的逆问题结果。

Comments 37 pages. Updated version

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AI中文摘要

我们将根簇理论从完美域推广到不一定完美的一般域。对于任意基域上的域扩张,我们引入了以下概念并研究了它们的性质:根簇大小、多簇大小及其推广根容量、多根容量;上升指数、上升正规指数及其推广交指数、交正规指数;复合指数和复合正规指数。我们在希尔伯特域上建立了这些广义概念的逆问题的结果,这推广了我们先前在数域上的结果。特别地,我们证明在给定的希尔伯特域上,存在给定次数、簇大小和多簇大小的多项式,以及存在给定根容量和多根容量的扩张(相对于该多项式)。

英文摘要

We extend the theory of root clusters from perfect fields to general fields which are not necessarily perfect. We introduce the following notions for field extensions over any given base field and study their interesting properties: root cluster size, multicluster size and their generalizations root capacity, multiroot capacity; ascending index, ascending normal index and their generalizations intersection indicium, intersection normal indicium; compositum indicium and compositum normal indicium. We establish our results on the Inverse problems for these generalized notions over Hilbertian fields which generalizes our earlier results which were over number fields. In particular, we show over a given Hilbertian field, the existence of a polynomial for given degree, cluster size and multicluster size and existence of an extension for given root capacity and multiroot capacity with respect to that polynomial.

2606.12194 2026-06-19 math.CO math.NT 新提交 80%

Beating Product Constructions for Linear Equations Over Finite Fields

击败有限域上线性方程组的乘积构造

Paul Hametner, Fred Tyrrell

专题命中 其他科学智能 :有限域上线性方程组的组合数学研究

AI总结 本文证明,对于任何避免非平凡解的亏格一平移不变线性方程的子集A,存在更高维度的子集B也避免非平凡解,且其密度大于A的密度,从而说明仅通过直接乘积无法得到渐近最优下界。

Comments 10 pages

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AI中文摘要

我们证明,对于任何 $A\subseteq \mathbb{F}_q^n$,如果它缺乏亏格一的平移不变线性方程的非平凡解(即系数的任何非空真子集之和不为 $0$),那么存在某个更高维度的集合 $B\subseteq \mathbb{F}_q^m$,它也缺乏非平凡解,并且满足 \\[|B|^{1/m}>|A|^{1/n}.\\] 特别地,这意味着在 $\mathbb{F}_3^n$ 中,没有固定的帽集能通过直接乘积单独给出渐近最优下界。

英文摘要

We show that for any $A\subseteq \mathbb{F}_q^n$ lacking non-trivial solutions to a translation-invariant linear equation of genus one, meaning that no nonempty proper subset of the coefficients sums to $0$, there is a set $B\subseteq \mathbb{F}_q^m$ in some higher dimension which also lacks non-trivial solutions, such that \[|B|^{1/m}>|A|^{1/n}.\] In particular, this implies that no fixed cap set in $\mathbb{F}_3^n$ gives an asymptotically optimal lower bound by direct products alone.

2606.10358 2026-06-19 cs.LG cs.AI 新提交 80%

KG-SoftMAP: Soft Knowledge-Graph Priors for Bayesian Network Structure Learning from Sparse Discrete Data

KG-SoftMAP: 基于软知识图谱先验的稀疏离散数据贝叶斯网络结构学习

Guoliang Xu, James E. Corter

发表机构 * Columbia University(哥伦比亚大学)

专题命中 其他科学智能 :贝叶斯网络结构学习,结合知识图谱先验

AI总结 针对稀疏离散数据中贝叶斯网络结构学习困难的问题,提出KG-SoftMAP方法,将加权有向知识图谱编码为软先验,结合BDeu评分与logit形式先验最大化MAP目标,在合成与真实数据上显著提升结构恢复性能。

Comments 41 pages including appendices, 2 figures

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AI中文摘要

从稀疏离散数据中学习贝叶斯网络(BN)结构是困难的:当每个实例仅记录少数变量时,大多数变量对缺乏可靠评分所需的联合观测,且纯数据方法恢复的结构很少。不完美的领域知识,可表示为加权有向知识图谱(KG),通常是可用的。我们提出KG-SoftMAP,它将这样的KG编码为软性的、置信度加权的、可被数据覆盖的边先验,并最大化结合BDeu评分与logit形式先验的MAP目标;KG可由专家整理或由LLM提取。在受控的合成基准(唯一具有真实DAG的设置)上,KG-SoftMAP在$\rho=0.05$时恢复部分有向结构(DF1从$0.14$到$0.29$,而基线接近零),当$\rho\geq0.2$时恢复更多(DF1从$0.46$到$0.96$),前提是配有一个信息丰富但不完美的KG;恢复性能随KG质量下降而优雅地退化。在无真实DAG的真实稀疏教育数据上,我们仅评估面向部署的指标:预测、校准和KG一致性。学习到的BN最好被解读为诊断模型:在SAF上,它落后于逻辑回归$0.03$的F1_FAIL,同时提供KG一致的边、校准的联合概率以及从任意观测概念子集的推理;当不存在有意义的KG时,判别式逻辑回归更可取。

英文摘要

Learning Bayesian network (BN) structure from sparse discrete data is hard: when each instance records only a few variables, most variable pairs lack the joint observations needed for reliable scoring, and data-only methods recover little structure. However, imperfect domain knowledge, expressible as a weighted directed knowledge graph (KG), is often available. We propose KG-SoftMAP, which encodes such a KG as a finite-strength, confidence-weighted edge prior and maximizes a MAP objective combining the BDeu score with a logit-form prior; the KG may be expert-curated or LLM-extracted. On synthetic benchmarks with known DAGs, KG-SoftMAP reaches Directed-F1 (DF1) $0.19$--$0.32$ at observation rate $ρ=0.05$ and DF1 $0.44$--$0.97$ at $ρ\geq0.2$, while every data-only learner tested stays near zero under the same sparse masks. Recovery tracks KG quality: controlled corruption degrades it smoothly, a zero-signal KG yields DF1 $0.00$, and a blindly LLM-extracted KG with imperfect precision and recall still drives substantial recovery. On three real sparse educational datasets, the learned BN acts as a concept-level posterior model: on SAF it matches logistic regression (LR) within $0.03$ F1_FAIL while providing an inspectable concept graph, calibrated Fail probabilities, and tractable posterior queries from partial observations.

2606.09545 2026-06-19 math.NT 新提交 80%

On the Smallest Counterexample to the Log-Concavity of the D'Arcais Polynomials

关于 D'Arcais 多项式对数凹性的最小反例

Steven Charlton, Bernhard Heim, Johann Stumpenhusen

专题命中 其他科学智能 :D'Arcais多项式对数凹性反例的数学研究

AI总结 通过改进渐近方法,确定了 D'Arcais 多项式对数凹性猜想的最小反例为 λ=65,214,507,758,400,并研究了反例的渐近密度。

Comments 17 pages; minor typos corrected

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AI中文摘要

最近,Starr 使用渐近方法反驳了 Heim--Neuhauser 和 Abdesselam 关于 D'Arcais 多项式对数凹性的猜想,但没有给出具体的反例。我们改进了渐近方法,给出了关于 $σ_{-1}$ 卷积的必要估计,并确定了第一个反例为 $λ=65\,214\,507\,758\,400$。我们还考虑了此类反例的渐近密度。

英文摘要

Recently, Starr used asymptotic methods to disprove a conjecture by Heim--Neuhauser and Abdesselam about the log-concavity of the D'Arcais polynomials, without giving an explicit counterexample. We refine the asymptotics, to give the necessary estimates on convolutions of $σ_{-1}$, and identify the first counterexample at $λ= 65\,214\,507\,758\,400$. We also consider the asymptotic density of such counterexamples.

2606.09524 2026-06-19 math.GR 新提交 80%

On the Quartic-free A-groups

关于四次自由A-群

Prashun Kumar

专题命中 其他科学智能 :有限群结构理论,纯数学研究

AI总结 研究四次自由A-群的结构,并确定可解四次自由A-群的导长。

Comments 7 pages

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AI中文摘要

一个有限群被称为四次自由的,如果它的阶不被任何素数$p$的$p^4$整除。一个有限群被称为$A$-群,如果它的所有Sylow子群都是阿贝尔群。本文的目的是提供四次自由$A$-群的显式结构。此外,在提供显式结构的过程中,我们还确定了可解四次自由$A$-群的导长。

英文摘要

A finite group is said to be quartic-free if its order is not divisible by $p^4$ of any prime $p$. A finite group is called an $A$-group if all of its Sylow subgroups are abelian. Objective of this paper is to provide explicit structure of a quartic-free $A$-group. Further in the process of providing the explicit structure we also determine the derived length of a solvable quartic-free $A$-group.

2605.03894 2026-06-19 math.AT math.CO 版本更新 80%

Quasimonophobic graphs and degree spectral sequences in discrete cubical homology

拟单恐惧图与离散立方同调中的度谱序列

Samira Sahar Jamil, Mark Behrens

专题命中 其他科学智能 :离散立方同调与图论,纯数学研究

AI总结 引入图的离散立方链复形上的度过滤,定义基于奇异n-立方体面的最大内射维数,研究由此产生的度谱序列,该序列插值离散立方同调与内射同调,并引入拟单恐惧性条件证明谱序列消失及内射同调同构于填充子立方后的CW复形同调,应用于计算Greene球面图的H_2。

Comments v3: corrected minor typos

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AI中文摘要

我们在图的离散立方链复形上引入度过滤,该过滤由奇异$n$-立方体面的最大内射维数定义,并研究由此过滤产生的度谱序列。该谱序列在图的离散立方同调$H_n(G)$与内射同调$H_n^{inj}(G)$之间插值,后者是基于内射奇异立方体的离散立方同调的一个变体。基于Babson等人的工作,我们引入了图的拟单恐惧性组合条件,并证明拟单恐惧性意味着度谱序列在某些双次数下消失,并且$H_n^{inj}(G)$同构于通过“填充”图的子立方体得到的CW复形的同调。这些结果应用于计算Greene球面图$G^{sph}_n$的$H_2(G_n^{sph})$。

英文摘要

We introduce the degree filtration on the discrete cubical chain complex of a graph, defined in terms of the maximal injective dimension of the facets of singular $n$-cubes, and study the degree spectral sequence which arises from this filtration. This spectral sequence interpolates between the discrete cubical homology of a graph $H_n(G)$ and the injective homology $H_n^{inj}(G)$, a variant of the discrete cubical homology based on injective singular cubes. Building on the work of Babson et al. we introduce the combinatorial condition of quasimonophobicity on graphs, and show quasimonophobicity implies both the vanishing of the degree spectral sequence in certain bidegrees, and implies $H_n^{inj}(G)$ is isomorphic to the homology of the CW complex obtained by ``filling in'' subcubes of the graph. These results are applied to compute $H_2(G_n^{sph})$ for the Greene sphere graphs $G^{sph}_n$.

2604.13240 2026-06-19 cs.CV cs.LG 版本更新 80%

A High-Resolution Landscape Dataset for Concept-Based XAI With Application to Species Distribution Models

基于概念的可解释AI的高分辨率景观数据集及其在物种分布模型中的应用

Augustin de la Brosse, Damien Garreau, Thomas Houet, Thomas Corpetti

发表机构 * Université Rennes 2, CNRS, Nantes Université, Univ Brest, LETG, UMR 6554(里昂大学第二分校、法国国家科学研究中心、南特大学、布列塔尼大学、LETG、UMR 6554) LTSER Zone Atelier Armorique(Armorique 领域实验室区) University of Würzburg, Center for Artificial Intelligence and Data Science(乌尔姆大学、人工智能与数据科学中心)

专题命中 其他科学智能 :可解释AI用于物种分布模型

AI总结 提出首个基于概念的可解释AI方法用于物种分布模型,利用高分辨率多光谱和LiDAR无人机影像构建景观概念数据集,通过Robust TCAV量化景观概念对模型预测的影响,案例研究验证了方法的有效性。

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AI中文摘要

绘制物种空间分布对于保护政策和入侵物种管理至关重要。物种分布模型(SDMs)是完成此任务的主要工具,具有两个目的:实现稳健的预测性能,同时提供关于分布驱动因素的生态见解。然而,深度学习SDMs日益增长的复杂性使得提取这些见解更具挑战性。为了调和这些目标,我们提出了首个基于概念的可解释AI(XAI)在SDMs中的实现。我们利用Robust TCAV(测试与概念激活向量)方法量化景观概念对模型预测的影响。为此,我们提供了一个新的开放获取的景观概念数据集,该数据集源自高分辨率多光谱和LiDAR无人机影像。它包括跨越15个不同景观概念的653个斑块和1,450个随机参考斑块,旨在适用于广泛的物种。我们通过两个水生昆虫(襀翅目和毛翅目)的案例研究,使用两个卷积神经网络和一个视觉Transformer来展示这种方法。结果表明,基于概念的XAI有助于根据专家知识验证SDMs,同时发现产生新生态假说的新颖关联。Robust TCAV还提供了景观层面的信息,对政策制定和土地管理有用。代码和数据集公开可用。

英文摘要

Mapping the spatial distribution of species is essential for conservation policy and invasive species management. Species distribution models (SDMs) are the primary tools for this task, serving two purposes: achieving robust predictive performance while providing ecological insights into the driving factors of distribution. However, the increasing complexity of deep learning SDMs has made extracting these insights more challenging. To reconcile these objectives, we propose the first implementation of concept-based Explainable AI (XAI) for SDMs. We leverage the Robust TCAV (Testing with Concept Activation Vectors) methodology to quantify the influence of landscape concepts on model predictions. To enable this, we provide a new open-access landscape concept dataset derived from high-resolution multispectral and LiDAR drone imagery. It includes 653 patches across 15 distinct landscape concepts and 1,450 random reference patches, designed to suit a wide range of species. We demonstrate this approach through a case study of two aquatic insects, Plecoptera and Trichoptera, using two Convolutional Neural Networks and one Vision Transformer. Results show that concept-based XAI helps validate SDMs against expert knowledge while uncovering novel associations that generate new ecological hypotheses. Robust TCAV also provides landscape-level information, useful for policy-making and land management. Code and datasets are publicly available.