Pub Date : 2025-12-29DOI: 10.1016/j.cjph.2025.12.034
Kolade M. Owolabi
Quantum hydrodynamic (QHD) models provide a self-consistent framework for describing the evolution of particle density and velocity fields in quantum systems, incorporating both classical and purely quantum dispersive effects. In this work, we analyze nonlinear wave interactions by deriving QHD equations from the nonlinear Schrödinger formalism and investigating their dynamical properties. We establish rigorous analytical results, including conservation laws, existence of weak solutions, and nonlinear stability of energy-minimizing states. Complementary numerical simulations using Fourier spectral methods combined with exponential time-stepping reveal rich nonlinear phenomena such as stationary solitons, breather formation, and quasi-elastic collisions, confirming theoretical predictions. The results demonstrate the applicability of QHD models to a variety of physical settings, including quantum plasmas, nonlinear optical media, and Bose–Einstein condensates, providing insights into both fundamental dynamics and potential technological applications.
{"title":"Quantum hydrodynamic modeling of nonlinear wave interactions","authors":"Kolade M. Owolabi","doi":"10.1016/j.cjph.2025.12.034","DOIUrl":"10.1016/j.cjph.2025.12.034","url":null,"abstract":"<div><div>Quantum hydrodynamic (QHD) models provide a self-consistent framework for describing the evolution of particle density and velocity fields in quantum systems, incorporating both classical and purely quantum dispersive effects. In this work, we analyze nonlinear wave interactions by deriving QHD equations from the nonlinear Schrödinger formalism and investigating their dynamical properties. We establish rigorous analytical results, including conservation laws, existence of weak solutions, and nonlinear stability of energy-minimizing states. Complementary numerical simulations using Fourier spectral methods combined with exponential time-stepping reveal rich nonlinear phenomena such as stationary solitons, breather formation, and quasi-elastic collisions, confirming theoretical predictions. The results demonstrate the applicability of QHD models to a variety of physical settings, including quantum plasmas, nonlinear optical media, and Bose–Einstein condensates, providing insights into both fundamental dynamics and potential technological applications.</div></div>","PeriodicalId":10340,"journal":{"name":"Chinese Journal of Physics","volume":"100 ","pages":"Pages 67-94"},"PeriodicalIF":4.6,"publicationDate":"2025-12-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146035645","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-27DOI: 10.1016/j.cjph.2025.12.031
Zhi-Chu Chen, Qingyu Cai, Ji-Yong Fu, Zhong-Xiao Man
We investigate the functionality and performance of quantum thermal machines (QTMs) implemented using multipartite open quantum systems coupled to independent non-equilibrium reservoirs. We focus on two distinct types of work in QTMs, namely, the work arising from the coherence of reservoirs and that supplied by an external source. With two- and three-body interactions within the working substance, we demonstrate that QTMs in the presence of reservoir coherence can attain unique operational modes unattainable in purely thermal reservoirs. Furthermore, the QTMs can perform both single tasks driven by multiple inputs and hybrid operations driven by a single input. We define a non-equilibrium free-energy-based efficiency to assess the performance of this class of QTMs. Within specific parameter ranges, reservoir coherence can be harnessed to enhance the efficiency of QTMs. Our findings offer valuable insights for designing QTMs with customized functions and for optimizing their performance by leveraging coherence in non-equilibrium reservoirs.
{"title":"The impact of coherence in non-equilibrium reservoirs on the functionality and performance of quantum thermal machines","authors":"Zhi-Chu Chen, Qingyu Cai, Ji-Yong Fu, Zhong-Xiao Man","doi":"10.1016/j.cjph.2025.12.031","DOIUrl":"10.1016/j.cjph.2025.12.031","url":null,"abstract":"<div><div>We investigate the functionality and performance of quantum thermal machines (QTMs) implemented using multipartite open quantum systems coupled to independent non-equilibrium reservoirs. We focus on two distinct types of work in QTMs, namely, the work arising from the coherence of reservoirs and that supplied by an external source. With two- and three-body interactions within the working substance, we demonstrate that QTMs in the presence of reservoir coherence can attain unique operational modes unattainable in purely thermal reservoirs. Furthermore, the QTMs can perform both single tasks driven by multiple inputs and hybrid operations driven by a single input. We define a non-equilibrium free-energy-based efficiency to assess the performance of this class of QTMs. Within specific parameter ranges, reservoir coherence can be harnessed to enhance the efficiency of QTMs. Our findings offer valuable insights for designing QTMs with customized functions and for optimizing their performance by leveraging coherence in non-equilibrium reservoirs.</div></div>","PeriodicalId":10340,"journal":{"name":"Chinese Journal of Physics","volume":"99 ","pages":"Pages 549-562"},"PeriodicalIF":4.6,"publicationDate":"2025-12-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145921008","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Through first-principles calculations, we systematically explored the evolution of the electronic structure of MoSi2N4/GeI2 van der Waals heterostructure (vdWH) under biaxial strain, interlayer separation, and externally applied perpendicular electric fields. The pristine vdWH emerges as a direct-gap semiconductor with a bandgap of 1.69 eV. A compressive strain of 4% increases the bandgap to a maximum of 2.23 eV, whereas a tensile strain induces a precipitous reduction to 0.63 eV at 8%. Variations in interlayer spacing exert an equally pronounced influence: the bandgap broadens to 1.83 eV at 3.06 Å, but collapses abruptly to 0.16 eV upon further contraction to 1.56 Å. Perpendicular E-fields provide an additional lever of control; a modest field of -0.1 V Å-1 elevates the bandgap to 1.85 eV, while stronger fields of -0.5 V Å-1 quench the gap entirely, driving the system into a metallic state. The underlying mechanisms governing these bandgap modulations are elucidated in detail. Collectively, these results highlight the remarkable tunability of MoSi2N4/GeI2 vdWH, thereby providing a theoretical framework for the rational conception of next-generation devices in the optoelectronic and flexible electronic domains.
通过第一性原理计算，系统地探讨了MoSi2N4/GeI2范德华异质结构（vdWH）在双轴应变、层间分离和外加垂直电场作用下的电子结构演变。原始vdWH以带隙1.69 eV的直接隙半导体形式出现。当压缩应变为4%时，带隙增大到2.23 eV的最大值，而当拉伸应变为8%时，带隙急剧减小到0.63 eV。层间间距的变化也会产生同样明显的影响：在3.06 Å时，带隙变宽至1.83 eV，但在进一步收缩至1.56 Å时，带隙突然坍缩至0.16 eV。垂直的电场提供了额外的控制杠杆；适度的电场-0.1 V Å-1将带隙提升到1.85 eV，而更强的电场-0.5 V Å-1将带隙完全淬灭，使系统进入金属状态。详细阐明了控制这些带隙调制的基本机制。总的来说，这些结果突出了MoSi2N4/GeI2 vdWH的显著可调性，从而为光电和柔性电子领域的下一代器件的合理概念提供了理论框架。
{"title":"Multifield modulation of electronic structure in MoSi2N4/GeI2 van der Waals heterostructures","authors":"Yuanlei Zhao, Xuewen Wang, Yingying Zhao, Ting Zhu, Zhaoming Fu, Syed Awais Ahmad, Weibin Zhang, Quanhong Ou","doi":"10.1016/j.cjph.2025.12.028","DOIUrl":"10.1016/j.cjph.2025.12.028","url":null,"abstract":"<div><div>Through first-principles calculations, we systematically explored the evolution of the electronic structure of MoSi<sub>2</sub>N<sub>4</sub>/GeI<sub>2</sub> van der Waals heterostructure (vdWH) under biaxial strain, interlayer separation, and externally applied perpendicular electric fields. The pristine vdWH emerges as a direct-gap semiconductor with a bandgap of 1.69 eV. A compressive strain of 4% increases the bandgap to a maximum of 2.23 eV, whereas a tensile strain induces a precipitous reduction to 0.63 eV at 8%. Variations in interlayer spacing exert an equally pronounced influence: the bandgap broadens to 1.83 eV at 3.06 Å, but collapses abruptly to 0.16 eV upon further contraction to 1.56 Å. Perpendicular E-fields provide an additional lever of control; a modest field of -0.1 V Å<sup>-1</sup> elevates the bandgap to 1.85 eV, while stronger fields of -0.5 V Å<sup>-1</sup> quench the gap entirely, driving the system into a metallic state. The underlying mechanisms governing these bandgap modulations are elucidated in detail. Collectively, these results highlight the remarkable tunability of MoSi<sub>2</sub>N<sub>4</sub>/GeI<sub>2</sub> vdWH, thereby providing a theoretical framework for the rational conception of next-generation devices in the optoelectronic and flexible electronic domains.</div></div>","PeriodicalId":10340,"journal":{"name":"Chinese Journal of Physics","volume":"100 ","pages":"Pages 113-126"},"PeriodicalIF":4.6,"publicationDate":"2025-12-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146035642","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-24DOI: 10.1016/j.cjph.2025.12.030
Ling Lu , Haikong Lu , Bocheng Bao
To demonstrate the chaotic dynamics and homogeneous coexisting behaviors triggered by a Josephson junction (JJ), this study proposes a four-dimensional JJ-based system by coupling a JJ with a three-dimensional linear dynamical system. The equilibrium points with stability are discussed theoretically. By employing various numerical methods, the bifurcation behaviors that depend on the JJ parameters are investigated, and the homogeneous coexisting behaviors that depend on the initial-values are inspected. Theoretical analyses and numerical calculations manifest that the proposed system owns infinitely many isolated equilibrium points whose stability is associated with the JJ parameters and the JJ initial-value. The nonlinearity of JJ enables the proposed system to show chaotic dynamics, and the JJ initial-value offset can cause the proposed system to present homogeneous coexisting attractors. Finally, an analog circuit is developed to implement the JJ-based system, and the circuit simulations and hardware experiments confirm the numerical calculations.
{"title":"Chaotic dynamics and homogeneous coexisting behaviors in Josephson junction-based system","authors":"Ling Lu , Haikong Lu , Bocheng Bao","doi":"10.1016/j.cjph.2025.12.030","DOIUrl":"10.1016/j.cjph.2025.12.030","url":null,"abstract":"<div><div>To demonstrate the chaotic dynamics and homogeneous coexisting behaviors triggered by a Josephson junction (JJ), this study proposes a four-dimensional JJ-based system by coupling a JJ with a three-dimensional linear dynamical system. The equilibrium points with stability are discussed theoretically. By employing various numerical methods, the bifurcation behaviors that depend on the JJ parameters are investigated, and the homogeneous coexisting behaviors that depend on the initial-values are inspected. Theoretical analyses and numerical calculations manifest that the proposed system owns infinitely many isolated equilibrium points whose stability is associated with the JJ parameters and the JJ initial-value. The nonlinearity of JJ enables the proposed system to show chaotic dynamics, and the JJ initial-value offset can cause the proposed system to present homogeneous coexisting attractors. Finally, an analog circuit is developed to implement the JJ-based system, and the circuit simulations and hardware experiments confirm the numerical calculations.</div></div>","PeriodicalId":10340,"journal":{"name":"Chinese Journal of Physics","volume":"99 ","pages":"Pages 438-449"},"PeriodicalIF":4.6,"publicationDate":"2025-12-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145880958","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Traditional quantum operation teleportation protocols require the transmission of photons through quantum channels, which are subject to certain vulnerabilities. This paper proposes a counterfactual bidirectional quantum operation teleportation protocol, which enables the counterfactual remote transmission of quantum operations in both directions without the need for actual quantum state transmission or pre-shared entanglement. Compared to existing quantum operation teleportation protocols, this protocol offers enhanced security, providing a novel technical pathway for the widespread application of quantum communication.
{"title":"Counterfactual bidirectional quantum operation teleportation protocol","authors":"Rui-Chen Huang , Yu-Guang Yang , Guang-Bao Xu , Dong-Huan Jiang","doi":"10.1016/j.cjph.2025.12.027","DOIUrl":"10.1016/j.cjph.2025.12.027","url":null,"abstract":"<div><div>Traditional quantum operation teleportation protocols require the transmission of photons through quantum channels, which are subject to certain vulnerabilities. This paper proposes a counterfactual bidirectional quantum operation teleportation protocol, which enables the counterfactual remote transmission of quantum operations in both directions without the need for actual quantum state transmission or pre-shared entanglement. Compared to existing quantum operation teleportation protocols, this protocol offers enhanced security, providing a novel technical pathway for the widespread application of quantum communication.</div></div>","PeriodicalId":10340,"journal":{"name":"Chinese Journal of Physics","volume":"99 ","pages":"Pages 535-548"},"PeriodicalIF":4.6,"publicationDate":"2025-12-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145920906","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-23DOI: 10.1016/j.cjph.2025.12.022
Tanya Srivastava , Nilam VenkataKoteswararao
A parametric study is done to investigate the change in fluid properties due to normal shock wave and turbulent flow interaction, taking into account the influence of the magnetic field. These effects are significant for the development of plasma propulsion systems, compressible fluid dynamics and aerospace technologies. A modified Rankine–Hugoniot model has been developed in order to accomplish this. The analysis begins with the derivation of governing equations that include the effects of the magnetic field for compressible and turbulent flow. The analysis has been enhanced further by using Artificial Neural Network techniques to predict Mach number and shock strength using a back-propagation algorithm that has been optimised using the Levenberg–Marquardt method. Turbulence intensity and magnetic fields significantly affect the compression process across the shock and downstream flow characteristics, leading to variations in density, velocity and Mach number ratios. These results offer new perspectives for the design and efficiency of high-speed flow systems and offer important insights into the dynamics of shocks in magnetised turbulent environments.
{"title":"Normal Shock Wave Propagation in Magnetized Turbulent Flow Using Analytical and Neural Network","authors":"Tanya Srivastava , Nilam VenkataKoteswararao","doi":"10.1016/j.cjph.2025.12.022","DOIUrl":"10.1016/j.cjph.2025.12.022","url":null,"abstract":"<div><div>A parametric study is done to investigate the change in fluid properties due to normal shock wave and turbulent flow interaction, taking into account the influence of the magnetic field. These effects are significant for the development of plasma propulsion systems, compressible fluid dynamics and aerospace technologies. A modified Rankine–Hugoniot model has been developed in order to accomplish this. The analysis begins with the derivation of governing equations that include the effects of the magnetic field for compressible and turbulent flow. The analysis has been enhanced further by using Artificial Neural Network techniques to predict Mach number and shock strength using a back-propagation algorithm that has been optimised using the Levenberg–Marquardt method. Turbulence intensity and magnetic fields significantly affect the compression process across the shock and downstream flow characteristics, leading to variations in density, velocity and Mach number ratios. These results offer new perspectives for the design and efficiency of high-speed flow systems and offer important insights into the dynamics of shocks in magnetised turbulent environments.</div></div>","PeriodicalId":10340,"journal":{"name":"Chinese Journal of Physics","volume":"100 ","pages":"Pages 23-38"},"PeriodicalIF":4.6,"publicationDate":"2025-12-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145975516","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The nature of black holes (BHs) and their potential deviations from classical General Relativity (GR) remain fundamental questions in modern astrophysics. Nonlinear electrodynamics (NED) has been proposed as a viable mechanism to construct regular BHs that avoid singularities while preserving essential astrophysical properties. In this work, we perform a comprehensive analysis of NED-inspired BHs, deriving constraints on the magnetic parameter through both theoretical analysis and Bayesian parameter estimation using Event Horizon Telescope (EHT) observations of shadow sizes and GRAVITY collaboration measurements of stellar orbits for Sgr A*. Our Markov Chain Monte Carlo (MCMC) analysis yields magnetic charge estimates consistent with zero: for M87* and for Sgr A*, establishing important upper limits while showing no evidence for significant magnetic charge in either source. We perform a comparative analysis of observational signatures including BH shadows (using , where Rsh is the shadow radius observed at infinity and rph is the photon sphere radius), and gravitational lensing under uniform and non-uniform plasma conditions, demonstrating how deviations from standard GR solutions emerge due to nonlinear electrodynamics. Our findings demonstrate that while current EHT data do not require non-zero magnetic charge, NED-induced modifications could leave detectable imprints on strong-field astrophysical processes, providing new opportunities to test alternative theories of gravity. Future missions, including the Laser Interferometer Space Antenna (LISA) and next-generation X-ray observatories, will play a crucial role in refining constraints on these theoretical models, building upon our MCMC-constrained parameter space while complementing ongoing observations from the EHT and precision mass measurements from instruments like GRAVITY, providing a more comprehensive understanding of BH physics and potential deviations from GR.
黑洞（BHs）的性质及其对经典广义相对论（GR）的潜在偏离仍然是现代天体物理学中的基本问题。非线性电动力学（NED）已被提出作为一种可行的机制来构建规则黑洞，以避免奇点，同时保持基本的天体物理特性。在这项工作中，我们对受ned启发的黑洞进行了全面的分析，利用事件视界望远镜（EHT）对阴影大小的观测和Sgr a *恒星轨道的重力协作测量，通过理论分析和贝叶斯参数估计推导出磁参数的约束。我们的马尔可夫链蒙特卡罗（MCMC）分析得出了与零一致的磁荷估计：M87*的q=−0.0009−0.4908+0.4915×109M⊙，Sgr A*的q=−0.0000−0.4553+0.4532×106M⊙，建立了重要的上限，但没有证据表明两个源都存在显著的磁荷。我们对观测特征进行了比较分析，包括黑洞阴影（使用Rsh=rph/f(rph)，其中Rsh是在无穷远处观测到的阴影半径，rph是光子球半径），以及均匀和非均匀等离子体条件下的引力透镜，展示了非线性电动力学如何导致标准GR解的偏差。我们的研究结果表明，虽然目前的EHT数据不需要非零磁荷，但ned诱导的修改可能会在强场天体物理过程中留下可检测的印记，为测试其他引力理论提供了新的机会。未来的任务，包括激光干涉仪空间天线（LISA）和下一代x射线天文台，将在完善这些理论模型的约束方面发挥关键作用，建立在mcmc约束的参数空间上，同时补充EHT正在进行的观测和重力等仪器的精确质量测量，提供对黑洞物理和潜在偏差的更全面的理解。
{"title":"Observational signatures of the Schwarzschild-like black hole","authors":"Javokhir Sharipov , Mirzabek Alloqulov , Pankaj Sheoran , Sanjar Shaymatov","doi":"10.1016/j.cjph.2025.12.024","DOIUrl":"10.1016/j.cjph.2025.12.024","url":null,"abstract":"<div><div>The nature of black holes (BHs) and their potential deviations from classical General Relativity (GR) remain fundamental questions in modern astrophysics. Nonlinear electrodynamics (NED) has been proposed as a viable mechanism to construct regular BHs that avoid singularities while preserving essential astrophysical properties. In this work, we perform a comprehensive analysis of NED-inspired BHs, deriving constraints on the magnetic parameter through both theoretical analysis and Bayesian parameter estimation using Event Horizon Telescope (EHT) observations of shadow sizes and GRAVITY collaboration measurements of stellar orbits for Sgr A*. Our Markov Chain Monte Carlo (MCMC) analysis yields magnetic charge estimates consistent with zero: <span><math><mrow><mi>q</mi><mo>=</mo><mo>−</mo><mn>0</mn><mo>.</mo><msubsup><mn>0009</mn><mrow><mo>−</mo><mn>0.4908</mn></mrow><mrow><mo>+</mo><mn>0.4915</mn></mrow></msubsup><mo>×</mo><msup><mn>10</mn><mn>9</mn></msup><msub><mi>M</mi><mo>⊙</mo></msub></mrow></math></span> for M87* and <span><math><mrow><mi>q</mi><mo>=</mo><mo>−</mo><mn>0</mn><mo>.</mo><msubsup><mn>0000</mn><mrow><mo>−</mo><mn>0.4553</mn></mrow><mrow><mo>+</mo><mn>0.4532</mn></mrow></msubsup><mo>×</mo><msup><mn>10</mn><mn>6</mn></msup><msub><mi>M</mi><mo>⊙</mo></msub></mrow></math></span> for Sgr A*, establishing important upper limits while showing no evidence for significant magnetic charge in either source. We perform a comparative analysis of observational signatures including BH shadows (using <span><math><mrow><msub><mi>R</mi><mtext>sh</mtext></msub><mo>=</mo><msub><mi>r</mi><mtext>ph</mtext></msub><mo>/</mo><msqrt><mrow><mi>f</mi><mo>(</mo><msub><mi>r</mi><mtext>ph</mtext></msub><mo>)</mo></mrow></msqrt></mrow></math></span>, where <em>R</em><sub>sh</sub> is the shadow radius observed at infinity and <em>r</em><sub>ph</sub> is the photon sphere radius), and gravitational lensing under uniform and non-uniform plasma conditions, demonstrating how deviations from standard GR solutions emerge due to nonlinear electrodynamics. Our findings demonstrate that while current EHT data do not require non-zero magnetic charge, NED-induced modifications could leave detectable imprints on strong-field astrophysical processes, providing new opportunities to test alternative theories of gravity. Future missions, including the Laser Interferometer Space Antenna (LISA) and next-generation X-ray observatories, will play a crucial role in refining constraints on these theoretical models, building upon our MCMC-constrained parameter space while complementing ongoing observations from the EHT and precision mass measurements from instruments like GRAVITY, providing a more comprehensive understanding of BH physics and potential deviations from GR.</div></div>","PeriodicalId":10340,"journal":{"name":"Chinese Journal of Physics","volume":"99 ","pages":"Pages 461-480"},"PeriodicalIF":4.6,"publicationDate":"2025-12-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145921007","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-18DOI: 10.1016/j.cjph.2025.12.020
Xueling Liu , Jing Huang , Yufeng Zhang , Junlin Li
As is well known, most models in scientific research and engineering feature asymmetric potentials. Gaining a deeper understanding of how the symmetry-breaking phenomenon affects the response mechanisms of systems is both meaningful and crucial. In this paper, we primarily explore the dynamic properties, including bifurcation and chaos, of a bi-frequency excited fractional Duffing oscillator with distributed time delay, whose symmetry is disrupted by a quadratic nonlinearity. First, via the method of direct partition of motions, the original system is transformed into an equivalent integer-order slow system, where the saddle-node bifurcation and vibrational resonance, induced by system parameters, are observed. It is found that the saddle-node bifurcation will transition to a pitchfork bifurcation if the quadratic nonlinearity vanishes. Then, by applying the Melnikov method to the system, we rigorously define two distinct critical conditions for chaos, each corresponding to the left and right sides of homoclinic orbits. Bifurcation diagram, largest Lyapunov exponents, and phase portrait, further confirm the accuracy of the theoretical predictions. Finally, to suppress the chaos, a parameter periodic excitation is introduced, and additionally, a criterion for chaos inhibition is established. Numerical simulations reveal that the control effect is both pronounced and noticeable. This work provides a theoretical basis for detecting the bifurcation and chaos in fractional models with asymmetric characteristics.
{"title":"Bifurcation and chaos control of a fractional Duffing oscillator with asymmetric potential and distributed time delay","authors":"Xueling Liu , Jing Huang , Yufeng Zhang , Junlin Li","doi":"10.1016/j.cjph.2025.12.020","DOIUrl":"10.1016/j.cjph.2025.12.020","url":null,"abstract":"<div><div>As is well known, most models in scientific research and engineering feature asymmetric potentials. Gaining a deeper understanding of how the symmetry-breaking phenomenon affects the response mechanisms of systems is both meaningful and crucial. In this paper, we primarily explore the dynamic properties, including bifurcation and chaos, of a bi-frequency excited fractional Duffing oscillator with distributed time delay, whose symmetry is disrupted by a quadratic nonlinearity. First, via the method of direct partition of motions, the original system is transformed into an equivalent integer-order slow system, where the saddle-node bifurcation and vibrational resonance, induced by system parameters, are observed. It is found that the saddle-node bifurcation will transition to a pitchfork bifurcation if the quadratic nonlinearity vanishes. Then, by applying the Melnikov method to the system, we rigorously define two distinct critical conditions for chaos, each corresponding to the left and right sides of homoclinic orbits. Bifurcation diagram, largest Lyapunov exponents, and phase portrait, further confirm the accuracy of the theoretical predictions. Finally, to suppress the chaos, a parameter periodic excitation is introduced, and additionally, a criterion for chaos inhibition is established. Numerical simulations reveal that the control effect is both pronounced and noticeable. This work provides a theoretical basis for detecting the bifurcation and chaos in fractional models with asymmetric characteristics.</div></div>","PeriodicalId":10340,"journal":{"name":"Chinese Journal of Physics","volume":"99 ","pages":"Pages 341-355"},"PeriodicalIF":4.6,"publicationDate":"2025-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145837434","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-18DOI: 10.1016/j.cjph.2025.12.023
Ran Sun , Jing Li , Shaotao Zhu , Xinxing Zhou
The investigation of chaotic characteristics in multi-well nonlinear systems is one of the key issues for advancing their engineering applications. However, existing studies on the dynamical behaviors of multi-homoclinic orbits and inter-well motions in multistable systems remain insufficient. A spring-coupled rotational inverted pendulum system (SRIP) was established by combining an inverted pendulum and a two-dimensional planar oscillator, enabling the structural multi-stability and homoclinic orbit characteristics to be modulated through parameter adjustments. The equations of motion for both the single-degree-of-freedom(SDOF) and the two-degree-of-freedom(2DOF) SRIP system were derived using Lagrange’s equations. The chaotic response characteristics were then analyzed via the energy and Melnikov functions of homoclinic orbits. The contour plots of energy function for the SDOF SRIP system characterize the topological structures of its phase plane, while the bifurcation characteristics of equilibrium points were examined by analyzing the stability of local extrema in the potential function. Homoclinic bifurcations were depicted by the contours corresponding to the energy levels of unstable equilibrium points. For the 2DOF system, dimensional reduction was performed, and a semi-analytical approach combining Melnikov functions was applied to evaluate the oriented distances between stable and unstable manifolds of various types of homoclinic orbits, thereby characterizing the chaotic responses under perturbations. Numerical simulations validated the analytical results. With increasing coupling stiffness, pitchfork bifurcations of equilibrium points and homoclinic-heteroclinic bifurcations emerge. Under larger excitation amplitudes, both confined and rotational chaos occur, and global characteristics of the attractors were qualitatively analyzed via maximal Lyapunov exponent and Poincar maps.
{"title":"Melnikov analysis of multiple homoclinic orbits in the spring-coupled rotational inverted pendulum","authors":"Ran Sun , Jing Li , Shaotao Zhu , Xinxing Zhou","doi":"10.1016/j.cjph.2025.12.023","DOIUrl":"10.1016/j.cjph.2025.12.023","url":null,"abstract":"<div><div>The investigation of chaotic characteristics in multi-well nonlinear systems is one of the key issues for advancing their engineering applications. However, existing studies on the dynamical behaviors of multi-homoclinic orbits and inter-well motions in multistable systems remain insufficient. A spring-coupled rotational inverted pendulum system (SRIP) was established by combining an inverted pendulum and a two-dimensional planar oscillator, enabling the structural multi-stability and homoclinic orbit characteristics to be modulated through parameter adjustments. The equations of motion for both the single-degree-of-freedom(SDOF) and the two-degree-of-freedom(2DOF) SRIP system were derived using Lagrange’s equations. The chaotic response characteristics were then analyzed via the energy and Melnikov functions of homoclinic orbits. The contour plots of energy function for the SDOF SRIP system characterize the topological structures of its phase plane, while the bifurcation characteristics of equilibrium points were examined by analyzing the stability of local extrema in the potential function. Homoclinic bifurcations were depicted by the contours corresponding to the energy levels of unstable equilibrium points. For the 2DOF system, dimensional reduction was performed, and a semi-analytical approach combining Melnikov functions was applied to evaluate the oriented distances between stable and unstable manifolds of various types of homoclinic orbits, thereby characterizing the chaotic responses under perturbations. Numerical simulations validated the analytical results. With increasing coupling stiffness, pitchfork bifurcations of equilibrium points and homoclinic-heteroclinic bifurcations emerge. Under larger excitation amplitudes, both confined and rotational chaos occur, and global characteristics of the attractors were qualitatively analyzed via maximal Lyapunov exponent and Poincar<span><math><mrow><mover><mi>e</mi><mo>´</mo></mover></mrow></math></span> maps.</div></div>","PeriodicalId":10340,"journal":{"name":"Chinese Journal of Physics","volume":"99 ","pages":"Pages 393-411"},"PeriodicalIF":4.6,"publicationDate":"2025-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145880792","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-18DOI: 10.1016/j.cjph.2025.12.025
Jia-En Yang , Xiao-Long Lü , En-Jia Ye
Topological edge states are crucial for designing future electronic devices. This study achieves mixed coexisting spin-polarized antichiral and chiral edge states by radiating the upper or lower half of the stanene nanoribbons with off-resonant circularly polarized light. Specifically, the circularly polarized light alters the edge states on one boundary, while those on the other remain unchanged. Unlike the antichiral edge states achieved by the modified Haldane model, these photoinduced antichiral edge states are fragile with narrow nanoribbons but robust with wide ones. This nanoribbon width dependence is mainly because the associated bulk states behave similarly to the inner-edge state, whose robustness is related to the nanoribbon width. Using the mixed coexisting edge states, defect-induced and external-field-induced spin filters are proposed. These edge states and spin filters could prove vital for designing future electronic devices.
{"title":"Photoinduced coexistence of spin-polarized antichiral and chiral edge states enabling defect-induced spin filters","authors":"Jia-En Yang , Xiao-Long Lü , En-Jia Ye","doi":"10.1016/j.cjph.2025.12.025","DOIUrl":"10.1016/j.cjph.2025.12.025","url":null,"abstract":"<div><div>Topological edge states are crucial for designing future electronic devices. This study achieves mixed coexisting spin-polarized antichiral and chiral edge states by radiating the upper or lower half of the stanene nanoribbons with off-resonant circularly polarized light. Specifically, the circularly polarized light alters the edge states on one boundary, while those on the other remain unchanged. Unlike the antichiral edge states achieved by the modified Haldane model, these photoinduced antichiral edge states are fragile with narrow nanoribbons but robust with wide ones. This nanoribbon width dependence is mainly because the associated bulk states behave similarly to the inner-edge state, whose robustness is related to the nanoribbon width. Using the mixed coexisting edge states, defect-induced and external-field-induced spin filters are proposed. These edge states and spin filters could prove vital for designing future electronic devices.</div></div>","PeriodicalId":10340,"journal":{"name":"Chinese Journal of Physics","volume":"99 ","pages":"Pages 383-392"},"PeriodicalIF":4.6,"publicationDate":"2025-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145880789","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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