检索结果-内蒙古大学图书馆

Balancing mobility behaviors to avoid global epidemics from local outbreaks

Physical Review E 2025年第3期111卷 L032302-L032302页

作者： Pablo Valgañón Antonio Brotons David Soriano-Paños Jesús Gómez-Gardeñes Department of Condensed Matter Physics University of Zaragoza 50009 Zaragoza Spain GOTHAM laboratory Institute for Biocomputation and Physics of Complex Systems (BIFI) University of Zaragoza 50018 Zaragoza Spain Departament d'Enginyeria Informàtica i Matemàtiques Universitat Rovira i Virgili 43007 Tarragona Spain

Human interactions and mobility shape epidemic dynamics by facilitating disease outbreaks and their spatial spread across regions. Traditional models often isolate commuting and random mobility as separate behaviors, focusing either on short, recurrent trips or on random, exploratory movements. Here, we propose a unified formalism that allows a smooth transition between commuting and exploratory behavior based on travel and return probabilities. We derive an analytical expression for the epidemic threshold, revealing a nonmonotonic dependence on recurrence rates: while recurrence tends to lower the threshold by increasing agent concentration in high-contact hubs, it counterintuitively raises the invasion threshold in low-mobility scenarios, suggesting that allowing recurrence may foster local outbreaks while suppressing global epidemics. These results provide a comprehensive understanding of the interplay between human mobility patterns and epidemic spread, with implications for containment strategies in structured populations.

关键词：

来源：评论

学校读者我要写书评

暂无评论

Quantum beat spectroscopy of repulsive Bose polarons

引用

Physical Review Research 2025年第2期7卷 L022002-L022002页

作者： A. M. Morgen S. S. Balling K. Knakkergaard Nielsen T. Pohl G. M. Bruun J. J. Arlt Center for Complex Quantum Systems Department of Physics and Astronomy Aarhus University Ny Munkegade 120 DK-8000 Aarhus C Denmark Max-Planck Institute for Quantum Optics Hans-Kopfermann-Straße 1 D-85748 Garching Germany Institute for Theoretical Physics Vienna University of Technology Wiedner Hauptstraße 8-10 A-1040 Vienna Austria

The physics of impurities in a bosonic quantum environment is a paradigmatic and challenging many-body problem. Here, this problem is investigated for impurities with strong repulsive interactions based on Ramsey interferometry in a quantum degenerate gas of K39 atoms. We observe revivals in the amplitude of the interferometric signal and identify them as beat signals between two coexisting quasiparticle branches, the attractive and repulsive polarons. The interferometric signal allows for an extraction of their energies for a wide range of interaction strengths, thus resolving outstanding discrepancies in earlier spectroscopic measurements. Furthermore, we identify several dynamical regimes in the formation of the repulsive Bose polaron. Our results improve the understanding of quantum impurities interacting strongly with a bosonic environment and show how short-lived nonequilibrium many-body states can be probed using quantum beat spectroscopy.

关键词： Polarons

来源：评论

学校读者我要写书评

暂无评论

Non-Landau quantum phase transition in modulated SU(N) Heisenberg spin chains

引用

Physical Review B 2025年第2期111卷 L020404-L020404页

作者： Sylvain Capponi Lukas Devos Philippe Lecheminant Keisuke Totsuka Laurens Vanderstraeten Laboratoire de Physique Théorique Université de Toulouse CNRS UPS Toulouse France Department of Physics and Astronomy Ghent University Ghent Belgium Laboratoire de Physique Théorique et Modélisation CNRS CY Cergy Paris Université 95302 Cergy-Pontoise Cedex France Center for Gravitational Physics and Quantum Information Yukawa Institute for Theoretical Physics Kyoto University Kyoto 606-8502 Japan Center for Nonlinear Phenomena and Complex Systems Université Libre de Bruxelles Bruxelles Belgium

We investigate the nature of the quantum phase transition in modulated SU(N) Heisenberg spin chains. In the odd-N case, the transition separates a trivial nondegenerate phase to a doubly degenerate gapped chiral PSU(N) symmetry-protected topological (SPT) phase which breaks spontaneously the inversion symmetry. The transition is not an Ising transition associated to the breaking of the Z2 inversion symmetry, but is governed by the delocalization of the edge states of the SPT phase. In this respect, a modulated SU(N) Heisenberg spin chain provides a simple example in one dimension of a non-Landau phase transition which is described by the SU(N)1 conformal field theory. We show that the chiral SPT phase exhibits fractionalized spinon excitations, which can be confined by slightly changing the model parameters.

关键词： Ising model

来源：评论

学校读者我要写书评

暂无评论

Generalized Haldane map from the matrix product state path integral to the critical theory of the J1−J2 chain

引用

Physical Review Research 2025年第1期7卷 L012037-L012037页

作者： F. Azad Adam J. McRoberts Chris Hooley A. G. Green Electrical Engineering and Computer Science Department Technische Universität Berlin 10587 Berlin Germany London Centre for Nanotechnology University College London Gordon Street London WC1H 0AH United Kingdom International Centre for Theoretical Physics Strada Costiera 11 34151 Trieste Italy Max Planck Institute for the Physics of Complex Systems Nöthnitzer Straße 38 01187 Dresden Germany

We study the J1−J2 spin-1/2 chain using a path integral constructed over matrix product states (MPS). By virtue of its nontrivial entanglement structure, the MPS ansatz captures the key phases of the model even at a semiclassical, saddle-point level, and, as a variational state, is in good agreement with the field theory obtained by Abelian bosonization. Going beyond the semiclassical level, we show that the MPS ansatz facilitates a physically motivated derivation of the field theory of the critical phase: By carefully taking the continuum limit—a generalization of the Haldane map—we recover from the MPS path integral a field theory with the correct topological term and emergent SO(4) symmetry, constructively linking the microscopic states and topological field-theoretic structures. Moreover, the dimerization transition is particularly clear in the MPS formulation—an explicit dimerization potential becomes relevant, gapping out the magnetic fluctuations.

关键词： Topology

来源：评论

学校读者我要写书评

暂无评论

Unconventional p-wave and finite-momentum superconductivity induced by altermagnetism through the formation of Bogoliubov Fermi surface

引用

Physical Review B 2025年第5期111卷 054501-054501页

作者： SeungBeom Hong Moon Jip Park Kyoung-Min Kim Department of Physics Hanyang University Seoul 04763 Republic of Korea Research Institute for Natural Science Hanyang University Seoul 04763 Republic of Korea Center for Theoretical Physics of Complex Systems Institute for Basic Science Daejeon 34126 Republic of Korea

Altermagnets are an exotic class of magnetic materials in which the Fermi surface exhibits a momentum-dependent spin-splitting while maintaining net-zero magnetization. Previous studies showed that this distinctive spin splitting can induce chiral p-wave superconductors or Fulde-Ferrell (FF) superconducting states carrying finite momentum. However, the underlying mechanisms of such unconventional superconductivities remain elusive. Here, we propose that the formation of the Bogoliubov Fermi surface (BFS) through the exchange field can play a significant role in such phenomena. Through a systematic self-consistent mean-field analysis of the extended attractive Hubbard model combined with the d-wave spin splitting induced by the exchange field, as observed in RuO2, we demonstrate that the formation of the BFS suppresses conventional spin-singlet superconducting states with s-wave characteristics. In contrast, the chiral p-wave state maintains a fully gapped spectrum without the Fermi surface, thereby becoming the ground state in the strong-field regime. In the intermediate regime, we find that the FF state becomes the predominant state through the optimization of available channels for Cooper pairing. Moreover, we illustrate how the prevalence of the chiral p-wave and FF states over the s-wave state changes under the variation of the field strength or chemical potential. Our findings provide valuable insights into potential pathways for realizing sought-after topological p-wave superconductivity and finite-momentum pairing facilitated by altermagnetism.

关键词： Hubbard model

来源：评论

学校读者我要写书评

暂无评论

Boundary-induced Majorana coupling in a planar topological Josephson junction

引用

Physical Review B 2025年第4期111卷 045414-045414页

作者： Hyeongseop Kim Sang-Jun Choi H.-S. Sim Sunghun Park Department of Physics Korea Advanced Institute of Science and Technology Daejeon 34141 Republic of Korea Present address: Department of Physics Education Kongju National University Gongju 32588 Republic of Korea. Center for Theoretical Physics of Complex Systems Institute for Basic Science (IBS) Daejeon 34126 Republic of Korea

Understanding environmental effects in a topological Josephson junction is vital for identifying signatures of Majorana modes. We consider a planar Josephson junction formed on the surface of a three-dimensional topological insulator, which possesses Majorana modes inside the junction and boundary modes outside. We find that tunneling between the inner and outer modes gives rise to effective coupling between the inner Majorana modes and hence induces energy splitting of their states even in the absence of the direct spatial overlap of their wave functions. The energy splitting is obtained analytically in the weak tunneling limit and is numerically investigated for an arbitrary tunneling strength. We discuss in detail the evolution of the energy splitting with an external perpendicular magnetic field and its effect on the shape of the Fraunhofer pattern.

关键词： Topology

来源：评论

学校读者我要写书评

暂无评论

Decay rates of optical modes unveiling the island structures in mixed phase space

引用

Physical Review A 2025年第3期111卷 033509-033509页

作者： Chang-Hwan Yi Barbara Dietz Jae-Ho Han Jung-Wan Ryu Center for Theoretical Physics of Complex Systems IBS Daejeon 34126 Korea Basic Science Program Korea University of Science and Technology (UST) Daejeon 34113 Korea Department of Physics Korea Advanced Institute of Science and Technology (KAIST) Daejeon 34141 Korea

We explore the decay rates of optical modes in asymmetric microcavities with mixed phase space across a wide range of wavelengths that extend deep into the semiclassical, i.e., short-wavelength, limit. Implementing an efficient numerical method, we computed 106 eigenmodes and discovered that certain decay rates form sequential separate branches with increasing wave number that eventually merge into smooth curves. The analysis of the localization properties and Husimi distributions reveals that each branch corresponds to a periodic orbit in the closed classical system. Our findings show that these decay rates gradually resolve the structure of the islands in mixed phase space as we approach the short-wavelength limit. We present an effective semiclassical model incorporating wave-number-dependent localization, Fresnel reflection, and the Goos-Hänchen shift and demonstrate that these effects are crucial in accounting for the observed branches of decay rate curves.

关键词： Microcavities

来源：评论

学校读者我要写书评

暂无评论

Precritical anomalous scaling and magnetization temperature dependence in cubic ferromagnetic crystals

引用

Physical Review B 2025年第10期111卷 104433-104433页

作者： Igor Kolokolov Victor S. L'vov Anna Pomyalov L.D. Landau Institute for Theoretical Physics Ak. Semenova 1-A Chernogolovka 142432 Moscow region Russia National Research University Higher School of Economics 101000 Myasnitskaya 20 Moscow Russia Department of Physics of Complex Systems Weizmann Institute of Science Rehovot 76100 Israel Department of Chemical and Biological Physics Weizmann Institute of Science Rehovot 76100 Israel

Recent developments in spintronics have drawn renewed attention to the spin dynamics of cubic ferromagnetic crystals EuO and EuS. These ferromagnets have the simplest possible magnetic structure, making them the most suitable systems for testing various theoretical models of magnetic materials. A commonly used Weiss mean-field approximation (MFA) provides only a qualitative description of the magnetization temperature dependence M(T). We develop a consistent theory for M(T) based on the perturbation diagrammatic technique for spin operators. Our theory is in excellent quantitative agreement with the experimental dependence of M(T) for EuO and EuS throughout the entire temperature range from T=0 to Curie temperature TC. In particular, our theoretical dependence M(T) demonstrates a scaling behavior M(T)∝(TC−T)β* with the scaling index β*≈1/3 in a wide range of temperatures, in agreement with the experimentally observed apparent scaling in EuO and EuS. The scaling behavior with β*≈1/3 is manifested in the temperature range T≲TC where corrections to the magnetization due to its fluctuations δM(T)≲M(T). To distinguish it from the narrow “critical” range T≈TC with δM(T)>M(T), we term this T-range “precritical.” The precritical corrections δM(T) are still large enough to affect the M(T) behavior. The index β* fundamentally differs from the “normal” scaling index βMFA=1/2 predicted by the MFA, which neglects the magnetization fluctuations. We refer to the apparent magnetization scaling with β*≈1/3, which emerges in our theory, as “precritical anomalous.”

关键词： Ferromagnetism

来源：评论

学校读者我要写书评

暂无评论

Emergence of Unpinned Dirac Points in Defected Photonic Crystals

arXiv

引用

arXiv 2025年

作者： Yi, Chang-Hwan Kim, Kyoung-Min Center for Theoretical Physics of Complex Systems Institute for Basic Science Daejeon34126 Korea Republic of Asia Pacific Center for Theoretical Physics Gyeongbuk Pohang37673 Korea Republic of Department of Physics Pohang University of Science and Technology Gyeongbuk Pohang37673 Korea Republic of

Unpinned Dirac points (DPs) are nodal point degeneracies that occur at generic momentum points lacking high symmetry, often exhibiting characteristics typically forbidden by symmetry. While this phenomenon has been observed in solid-state materials, the formation of unpinned DPs in photonic crystals has not been extensively studied. This study presents a novel approach to achieving unpinned DPs in two-dimensional "defected photonic crystals"—photonic superlattices created by modifying the size or refractive index of dielectric disks at specific sites. The defected photonic crystal hosts multiple unpinned DPs through accidental band crossings induced by rotational symmetry breaking across the nodal line degeneracies prevalent in the superlattice. Furthermore, the number of unpinned DPs, along with their positions and anisotropic dispersions, can be manipulated by adjusting the size or refractive index of the dielectric disks. This study pioneers the exploration of defected photonic crystals, proposing them as effective means of achieving unpinned DPs and facilitating the investigation of novel relativistic photonic wave phenomena with significant flexibility and control. © 2025, CC BY.

关键词： Crystal symmetry

来源：评论

学校读者我要写书评

暂无评论

Universally nondiverging Grüneisen parameter at critical points

引用

Physical Review B 2025年第6期111卷 L060409-L060409页

作者： Samuel M. Soares Lucas Squillante Henrique S. Lima Constantino Tsallis Mariano de Souza São Paulo State University (Unesp) IGCE - Physics Department Rio Claro - SP Brazil Centro Brasileiro de Pesquisas Físicas Rua Xavier Sigaud 150 Rio de Janeiro-RJ 22290-180 Brazil Centro Brasileiro de Pesquisas Físicas and National Institute of Science and Technology for Complex Systems Rua Xavier Sigaud 150 Rio de Janeiro 22290-180 Brazil Santa Fe Institute 1399 Hyde Park Road Santa Fe New Mexico 87501 USA Complexity Science Hub Vienna Metternichgasse 8 1030 Vienna Austria São Paulo State University (UNESP) Institute of Theoretical Physics São Paulo Brazil

According to Boltzmann-Gibbs (BG) statistical mechanics, the thermodynamic response, such as the isothermal susceptibility, at critical points (CPs) presents a divergent-like behavior. An appropriate parameter to probe both classical and quantum CPs is the so-called Grüneisen ratio Γ. Motivated by the results reported in [Phys. Rev. B 108, L140403 (2023)], we extend the quantum version of Γ to the nonadditive q-entropy Sq. Our findings indicate that using Sq at the unique value of q restoring the extensivity of the entropy, Γ is universally nondiverging at CPs. We unprecedentedly introduce Γ in terms of Sq, being BG recovered for q→1. We thus solve a long-standing problem related to the illusory diverging susceptibilities at CPs.

关键词： Entropy

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：