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Journal of Rare Earths 2025年第1期43卷 81-88,I0004页

作者： Ahmad Gholizadeh Sakineh Hosseini school of physics Damghan UniversityDamghanIran

Bismuth ferrite perovskite materials have recently attracted great attention because of their unique *** this study,Bi_(1-x)RE_(x)FeO_(3)(RE=La,Ce,Pr,Nd,Sm;x=0,0.05,0.1)thin films were deposited on glass substrates via low-temperature sol-gel assisted spin coating *** is found that in the presence of light rare-earth ions as the substitutions,the structural,morphological,and optical properties of the thin films are changed in the prepared thin *** find that the thin films have rhombohedral structures,and from field emission scanning electron microscopy(FESEM)images,it is observed that the substitution of light rare-earth ions for Bi^(3+)affects the surface morphology and grain size of the BiFeO_(3)(BFO)thin ***,the optical properties of prepared films were investigated via UV-visible *** all samples,the bandgap energy values are between 1.22 and 1.65 ***,the refractive index and extinction coefficient of samples are about 1.14-1.41 and 0.1-0.6,*** properties of the samples were investigated by measuring the degradation of methylene blue(MB)dye under irradiation of *** find that the light rare-earth substituted BFO thin films have better photocatalytic activity compared to pure BiFeO_(3) thin film,the reason can be described as the band gap varied between 1.20 and 1.65 eV for different rare earth ions which directly influences the photocatalytic properties of the investigated *** is observed that the prepared thin films can remove between 37.18%and 69.14%of dye after 180 min of *** study confirms that prepared thin films are a suitable candidate for photocatalytic applications.

关键词： Bismuth ferrite thin film Sol-gel spin coating Substitution effect Rareearth ions Photocatalytic activity

Observation of topological charge transformations in acoustic vortex using passive periodic systems

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Science China(physics,Mechanics & Astronomy) 2025年第1期68卷 136-143页

作者： Di-Chao Chen Xie Liu Changqing Xu Da-Jian Wu Ying Cheng Xiao-Jun Liu school of physics and Technology Nanjing Normal UniversityNanjing 210023China Key Laboratory of Modern Acoustics School of PhysicsNanjing UniversityNanjing 210093China

Vortex transmutation utilizes a periodic system,which not only enables the alteration of the topological charge(TC)of unstable input vortices but also facilitates their transformation into stable *** approach is crucial for investigating the characteristics of vortices in various wave ***,we achieve acoustic vortex TC transmutation by employing a welldesigned dual-structured plate external system(DPES).The interactions between the acoustic vortex and the finite-order discrete rotational symmetry lead to the transformation of its topological charge when complete rotational symmetry is broken to Nthorder discrete *** results experimentally demonstrate the acoustic vortex TC transmutation based on passive artificial structures,enabling numerous applications in particle manipulation and information multiplexing as well as advancing our understanding and control over free-space acoustic vortices.

关键词： acoustic vortex topological charge transformation artificial structure

Silk damping in scalar-induced gravitational waves:a novel probe for new physics

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Science China(physics,Mechanics & Astronomy) 2025年第1期68卷 75-81页

作者： Yan-Heng Yu Sai Wang Theoretical physics Division Institute of High Energy PhysicsChinese Academy of SciencesBeijing 100049China school of physics University of Chinese Academy of SciencesBeijing 100049China

Silk damping is well known in the study of cosmic microwave background(CMB)and accounts for suppression of the angular power spectrum of CMB on large angular *** this article,we study the effect of Silk damping on the scalar-induced gravitational waves(SIGWs).Resulting from the dissipation of cosmic fluid,the Silk damping notably suppresses the energy-density spectrum of SIGWs on scales comparable to a diffusion scale at the decoupling time of weakly-interacting *** effect offers a novel observable for probing the underlying particle interaction,especially for those mediated by heavy gauge bosons beyond the standard model of *** anticipate that pulsar timing arrays are sensitive to gauge bosons with mass∼10^(3)-10^(4)GeV,while space-and ground-based interferometers to those with mass∼10^(7)-10^(12)GeV,leading to essential comple-ments to on-going and future experiments of high-energy physics.

关键词： scalar-induced gravitational waves Silk damping new physics

Enhancing entanglement and steering in a hybrid atom–optomechanical system via Duffing nonlinearity

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Chinese physics B 2025年第2期34卷 124-131页

作者： Ling-Hui Dong Xiao-Jie Wu Cheng-Hua Bai Shao-Xiong Wu school of Semiconductor and physics North University of ChinaTaiyuan 030051China

We introduce a novel scheme for achieving quantum entanglement and Einstein–Podolsky–Rosen(EPR) steering between an atomic ensemble and a mechanical oscillator within a hybrid atom–optomechanical system. The system comprises an optical cavity, a two-level atomic ensemble and a mechanical resonator that possesses Duffing nonlinearity. The interaction between these components is mediated by the cavity mode, which is driven by an external laser. Our findings indicate that optimizing the coupling strengths between photons and phonons, as well as between atoms and the cavity,leads to maximal entanglement and EPR steering. The amplitude of the driving laser plays a pivotal role in enhancing the coupling between photons and phonons, and the system maintains robust entanglement and EPR steering even under high dissipation, thereby mitigating the constraints on initial conditions and parameter precision. Remarkably, the Duffing nonlinearity enhances the system's resistance to thermal noise, ensuring its stability and entanglement protection. Our analysis of EPR steering conditions reveals that the party with lower dissipation exhibits superior stability and a propensity to steer the party with higher dissipation. These discoveries offer novel perspectives for advancing quantum information processing and communication technologies.

关键词： quantum entanglement EPR steering optomechanical system Duffing nonlinearity

Observation of acoustic hybrid topological phases induced by the p-d orbital interactions

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Science China(physics,Mechanics & Astronomy) 2025年第1期68卷 128-135页

作者： Xiao Xiang Feng Gao Yu-Gui Peng Peng Wu Zong-Lin Li Xue-Feng Zhu school of physics and Innovation Institute Huazhong University of Science and TechnologyWuhan 430074China

In spinless systems,growing attention has recently been attracted to synthetic gauge fields,which redefine the fundamental crystal symmetries by utilizing the projective algebraic ***,synthetic gauge fields have been commonly investigated in single orbital systems,and explorations on hybrid orbitals remain elusive in ***,we report the experimental observation of hybrid topological phases induced by hybrid synthetic gauge flux,which is formed by the interaction between p and d orbitals embedded in acoustic *** breaking the translation symmetries of L_(x) and/or L_(y),we unambiguously demonstrate the first-order Möbius edge states and higher-order corner *** work establishes a platform for seeking exotic topological phases induced by hybrid-orbitals interactions and initializing the framework of hybrid-orbitalsrelated topological *** applications can be anticipated in scenarios such as high-quality sensing and robust wave trapping due to the stepwise energy distribution of the hybrid topological phase.

关键词： topological insulator synthetic gauge field projective symmetry corner states

Global Dynamics of a Kawasaki Disease Vascular Endothelial Cell Injury Model with Backward Bifurcation and Hopf Bifurcation

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Acta Mathematicae Applicatae Sinica 2025年第1期41卷 200-233页

作者： Ke GUO Wan-biao MA school of Mathematics and physics University of Science and Technology BeijingBeijing 100083China

Kawasaki disease(KD)is an acute,febrile,systemic vasculitis that mainly affects children under five years of *** this paper,we propose and study a class of 5-dimensional ordinary differential equation model describing the vascular endothelial cell injury in the lesion area of *** model exhibits forward/backward *** is shown that the vascular injury-free equilibrium is locally asymptotically stable if the basic reproduction number R_(0)1,and some explicit analytic expressions of ultimate lower bounds of the solutions of the model are *** results suggest that the control of vascular injury in the lesion area of KD is not only correlated with the basic reproduction number R_(0),but also with the growth rate of normal vascular endothelial cells promoted by the vascular endothelial growth factor.

关键词： Kawasaki disease model backward bifurcation Hopf bifurcation global stability permanence

Holographic thermodynamics of a charged AdS black hole with a global monopole

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Communications in Theoretical physics 2025年第2期77卷 148-160页

作者： Hebin Zheng Yunxian Chen Jian Tang school of physics and Astronomy China West Normal University Department of physics and Electronic Science Aba Teachers College

By regarding the Newton constant GNand cosmological constant Λ as variables, in this paper we study the thermodynamics and phase transition of the Reissner-Nordstr o m anti-de Sitter(RN-Ad S) black hole with a global monopole within the framework of Ad S/CFT correspondence. We find interesting critical phenomena and phase behavior in the(grand)canonical ensembles of fixed( Q,V,C),( Φ,V,C) and( Q,V,μ). When the other parameters are fixed, the free energy decreases with the global monopole increases. In the( Q,V,C) ensemble,the range of the unstable region decreases with the increase of the global monopole. In the( Φ,V,C) ensemble, when Φ < Φc, the free energy appears as two branches, where the upper and lower branches correspond to low and high entropy, respectively. When( Q,V,μ) is fixed, a new zero-order phase transition occurs in the high-entropy phase and the low-entropy phase at certainμ-dependent temperatures. When μ increases to a certain value, this zero-order phase transition disappears. This certain value is negatively related to the magnitude of the global ***, we find that p-V criticality does not appear with the change of global ***, it is important to note that the CFT states of charged black holes with global monopoles do not correspond to van der Waals fluids. Finally, we find that charged black holes with global monopoles can better reflect thermodynamic phase transitions and critical phenomena under the Ad S/CFT correspondence. By adjusting the change of the global monopole, the thermodynamic phase transition will also change.

关键词： black holes AdS-CFT correspondence global monopole

Supersymmetric hybrid inflation in light of CMB experiments and swampland conjectures

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Chinese physics C 2025年第1期49卷 114-126页

作者： Waqas Ahmed Shabbar Raza Center for Fundamental physics and school of Mathematics and physics Hubei Polytechnic UniversityHuangshi 435003China Department of physics Federal Urdu University of ArtsScience and TechnologyKarachi 75300Pakistan

In this study,we revisit supersymmetric(SUSY)hybrid inflation within the context of considering the latest Cosmic Microwave Background(CMB)observations and swampland *** demonstrate that SUSY hybrid inflation remains consistent with Planck 2018 data when radiative,soft mass,and supergravity(SUGRA)corrections are applied to the scalar *** is commonly perceived that SUSY hybrid inflation with a minimal Kahler potential results in a gauge symmetry breaking scale M of O(10^(15))GeV,leading to issues with the proton decay *** our analysis,we introduce a novel parameter space that alleviates the proton decay issue by achieving M~10^(16) GeV with M_(S)^(2)*** scenario necessitates a soft SUSY breaking scale|M_(S)|■10^(6) ***,we find that the tensor-to-scalar ratio r spans from 10^(-16) to 10^(-6),indicating a very small *** small ratio allows the modified swampland criteria to hold,although satisfying the trans-Planckian censorship conjecture(TCC)remains *** address this,we also explo non-minimal Kahler *** fixing the spectral index at n_(S)=0.9665,consistent with the central value of Planck 2018 data,and setting M=2×10^(16)GeV,we present our *** show that the canonical measure of primordial gravitational waves,r,for M_(S)=1 TeV,m_(3/2)=1 TeV,and k_(S)<0 for N=1 and N=2,ranges from 10^(-5) to 0.01,rendering it detectable by Planck and upcoming experiments such as LiteBIRD,Simons Observatory,PRISM,PIXIE,CORE,CMB-S4,and ***,we outline the parametric space and provide benchmark points for the non-minimal case to ensure compatibility with both the modified swampland conjecture and TCC.

关键词： suppersymmetry hybrid inflation swampland conjectures

Constraints on holographic QCD phase transitions from PTA observations

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Science China(physics,Mechanics & Astronomy) 2025年第1期68卷 67-74页

作者： Song He Li Li Sai Wang Shao-Jiang Wang Center for Theoretical physics and College of physics Jilin UniversityChangchun 130012China school of Physical Science and Technology Ningbo UniversityNingbo 315211China CAS Key Laboratory of Theoretical physics Institute of Theoretical PhysicsChinese Academy of SciencesBeijing 100190China school of Fundamental physics and Mathematical Sciences Hangzhou Institute for Advanced StudyUniversity of Chinese Academy of Sciences(UCAS)Hangzhou 310024China Theoretical physics Division Institute of High Energy PhysicsChinese Academy of SciencesBeijing 100049China school of Physical Sciences University of Chinese Academy of Sciences(UCAS)Beijing 100049China Max Planck Institute for Gravitational physics(Albert Einstein Institute) Am Muhlenberg 1Golm 14476Germany

The underlying physics of QCD phase transition in the early Universe remains largely unknown due to its strong-coupling nature during the quark-gluon plasma/hadron gas transition,yet a holographic model has been proposed to quantitatively fit the lattice QCD data while with its duration of the first-order phase transition(FoPT)left *** specific baryon chemical poten-tial,the first-order QCD phase transition agrees with the observational constraint of baryon ***,therefore,provides a scenario for phase transition gravitational waves(GWs)within the standard model of particle *** these background GWs could contribute dominantly to the recently claimed common-spectrum red noise from pulsar timing array(PTA)observations,the duration of this FoPT can be well constrained,and the associated primordial black holes are still allowed by current observations.

关键词： pulsar timing array QCD phase transition gravitational waves primordial black holes

New Taub-NUT black holes with massive spin-2 hair

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Science China(physics,Mechanics & Astronomy) 2025年第2期68卷 51-58页

作者： Yu-Qi Chen Hai-Shan Liu Center for Joint Quantum Studies and Department of physics School of ScienceTianjin UniversityTianjin 300350China

We consider Einstein gravity extended with quadratic curvature invariants,within which the well-known Ricci-flat Taub-NUT black hole remains a *** analysis of the unstable Lichnerowicz modes in the Taub-NUT background enables us to identify the mass and NUT parameters(m,n)where new Taub-NUT black holes can *** then adopt numerical techniques to construct these new Taub-NUT black holes,which bifurcate away from the Ricci-flat *** the Ricci-flat Taub-NUT,there can exist two new black holes for an appropriate given temperature,making it a total of three if we include the Ricci-flat one.

关键词： higher derivative gravity black hole solution Taub-NUT spacetime