Chaos Solitons & Fractals最新文献

{"title":"Bipartite synchronization of stochastic complex networks with time-varying delays and multi-links","authors":"Dong Hou,&nbsp;Xuelin Bai,&nbsp;Xin Zhao,&nbsp;Wenxue Li","doi":"10.1016/j.chaos.2025.116530","DOIUrl":"10.1016/j.chaos.2025.116530","url":null,"abstract":"<div><div>This article introduces a novel model to achieve bipartite leader-following synchronization of stochastic complex networks characterized by time-varying delays and multi-links, through the use of negative feedback control. Utilizing graph theory and the Lyapunov method, we develop global Lyapunov functions for the error system and derive new sufficient conditions for both mean-square exponential bipartite synchronization and almost sure exponential bipartite synchronization between the leader node and the follower nodes. These conditions are closely related to the topological properties of the complex networks, offering new insights and methodologies for synchronization control and stability analysis in stochastic complex networks. Finally, we validate the theoretical results by applying them to coupled Chua’s circuits and confirming their effectiveness and practicality through numerical simulations.</div></div>","PeriodicalId":9764,"journal":{"name":"Chaos Solitons & Fractals","volume":"198 ","pages":"Article 116530"},"PeriodicalIF":5.3,"publicationDate":"2025-05-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144083836","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Electric-field-biased control of irregular oscillations via multistability in a nonlinear terahertz meta-atom","authors":"Gervais Dolvis Leutcho,&nbsp;Gabriel Gandubert,&nbsp;Lyne Woodward,&nbsp;François Blanchard","doi":"10.1016/j.chaos.2025.116586","DOIUrl":"10.1016/j.chaos.2025.116586","url":null,"abstract":"<div><div>The split-ring resonator (SRR) has become widely popular in the design of artificial two-dimensional materials at the sub-wavelength scale, known as metasurfaces. When exposed to an intense electric field, this meta-atom deposited on a suitable substrate can exhibit electromagnetic coupling and become a bianisotropic meta-atom metasurface, where various nonlinear phenomena can occur. In this paper, the collective properties of the nonlinear SRR meta-atom model subjected to an alternating current (AC) and direct current (DC) field in the terahertz (THz) frequency portion of the spectrum are investigated in detail. Our investigation seeks to identify a new pathway to leverage the controlled bias field for reducing the required AC field that triggers the desired nonlinear effects. Using bi-parameter diagrams, we demonstrate how irregular oscillations emerge from controlling the DC field with a relatively low AC field. This result represents a key strategy and a promising route for translating these significant nonlinear interactions into practical, real-world applications utilizing nonlinear metasurfaces. To further examine some interesting properties correlated to the multi-sensitivity of the material in the low AC field regime, we first consider the normalized amplitude of the AC field as a control parameter for a fixed DC value. This approach reveals important phenomena, such as the transition to chaos via period-splitting bifurcation, as well as the emergence of multistable windows where the system exhibits a variety of coexisting periodic signals, including the coexistence of two and three distinct periodic patterns. Additionally, we uncover a rare case of bistability consisting of two different irregular signals. Next, the dynamic characteristics of the system are analyzed by varying the normalized DC field, for a fixed value of the normalized AC amplitude. In this situation, an interesting route to chaos is found through the creation and annihilation of periodic orbits. We also highlight a striking region in which the system exhibits the coexistence of three or two regular and irregular behaviors, resulting from a combination of hysteresis and parallel bifurcations. To distinguish these coexisting patterns, we compute the cross-sections of the initial domain, phase images, and time series associated with each signal. These findings substantially advance the development of multifunctional metasurface-based devices, with potential applications ranging from secure communication systems to enhanced signal detection.</div></div>","PeriodicalId":9764,"journal":{"name":"Chaos Solitons & Fractals","volume":"198 ","pages":"Article 116586"},"PeriodicalIF":5.3,"publicationDate":"2025-05-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144083755","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Disturbance estimator-based reinforcement learning robust stabilization control for a class of chaotic systems","authors":"Keyi Li ,&nbsp;Hongsheng Sha ,&nbsp;Rongwei Guo","doi":"10.1016/j.chaos.2025.116547","DOIUrl":"10.1016/j.chaos.2025.116547","url":null,"abstract":"<div><div>In the study, a novel optimal control tactics is developed for the stabilization of a class of chaotic systems. This strategy is depended on the positive gradient descent training mode and provides a critic-actor reinforcement learning (RL) algorithm, where the critic network is accustomed to approximate the nonlinear Hamilton–Jacobi–Bellman equation obtained from the outstanding performance evaluation index function with model uncertainties. The optimal controller is obtained by a network of actors, which includes a disturbance estimator (DE) as an observer composed of specially designed filters that can accurately suppress specified external disturbances. The entire system optimization process does not require persistent excitation (PE) of signal input. Then, a Lyapunov analysis method is provided to give a comprehensive assessment of system stability and optimal control performance. Last, the efficacy of the proposed controller approach is confirmed through simulation experiments.</div></div>","PeriodicalId":9764,"journal":{"name":"Chaos Solitons & Fractals","volume":"198 ","pages":"Article 116547"},"PeriodicalIF":5.3,"publicationDate":"2025-05-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144072285","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Floquet topological edge states at zigzag and twig edges of the graphenelike moiré lattice","authors":"Chengzhen Lu,&nbsp;Zengrun Wen,&nbsp;Guanhuai Cheng,&nbsp;Zhanghua Han,&nbsp;Yangjian Cai,&nbsp;Yuanmei Gao,&nbsp;Liren Zheng","doi":"10.1016/j.chaos.2025.116596","DOIUrl":"10.1016/j.chaos.2025.116596","url":null,"abstract":"<div><div>We present and demonstrate topological edge states in the graphenelike moiré lattice composed of helical waveguides. The longitudinal helical modulation induces an artificial gauge field, which breaks time reversal symmetry in the photonic graphenelike moiré lattice and gives rise to topological edge states. By calculating the Berry curvature and Chern numbers of all bulk bands, we further confirm the occurrence of a topological phase transition. The previous research has shown that the zigzag edge of the graphenelike moiré lattice supports edge states. Here, we theoretically and experimentally demonstrate that the twig edge also supports the edge states. The band structures for both the zigzag and twig edges reveal that the degenerate edge states transform into crossed unidirectional edge states within the helical waveguide configuration. We investigate the propagation dynamics of the topological edge states along both the zigzag edge and twig edge in helical waveguides array. The results show that the excited beam propagates unidirectionally along the edge without coupling into the bulk or experiencing backscattering, even in the presence of defect. Our findings indicate that the graphenelike photonic moiré lattice offers a novel platform for exploring topological physics and exhibits potential applications for the development of advanced optical devices.</div></div>","PeriodicalId":9764,"journal":{"name":"Chaos Solitons & Fractals","volume":"198 ","pages":"Article 116596"},"PeriodicalIF":5.3,"publicationDate":"2025-05-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144071141","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Explosive transitions in aging dynamics of coupled Hindmarsh-Rose neurons with distance-dependent interactions","authors":"Premraj Durairaj ,&nbsp;Sathiyadevi Kanagaraj ,&nbsp;Yingshan Guo ,&nbsp;Zhigang Zheng","doi":"10.1016/j.chaos.2025.116542","DOIUrl":"10.1016/j.chaos.2025.116542","url":null,"abstract":"<div><div>The abrupt onset of deterioration can have a profound impact on real-world situations, making it crucial to understand this process in order to prevent such events before they arise. In particular, understanding the dynamics of explosive transitions and aging behaviors in neural systems is essential for mitigating harmful illnesses. Importantly, we focus on such phenomena in coupled systems with distance-dependent interactions. Therefore, we primarily investigate the aging dynamics of globally coupled Hindmarsh-Rose (HR) neurons with distance-dependent interactions, concentrating on key factors such as coupling strength, inactive ratio, and decay rate that drive transitions between oscillatory and aging states. Through the use of the amplitude order parameter and bifurcation analysis, we identify the emergence of aging behaviors. Our findings show that increasing both the coupling strength and inactive ratio expands the aging region, while higher decay rates reverse aging dynamics by restoring rhythmic behavior. Importantly, we demonstrate bistability between aging (AG) and cluster oscillatory states (COS), exhibiting hysteresis characteristics. These results are validated through bifurcation and basin of attraction analysis, confirming the coexistence under varying initial conditions using a reduced model approach. Additionally, we explore the existence of explosive transitions and aging dynamics within complex network topologies, including small-world and random interactions. These findings significantly enhance our understanding of aging mechanisms in neural networks, with broader implications for brain aging, neuronal dysfunction, and other biological systems.</div></div>","PeriodicalId":9764,"journal":{"name":"Chaos Solitons & Fractals","volume":"198 ","pages":"Article 116542"},"PeriodicalIF":5.3,"publicationDate":"2025-05-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144072284","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Photonic spin Hall shift at four level gain-assisted dielectric medium","authors":"Qaisar Khan ,&nbsp;Ibrahim Aldayel ,&nbsp;Meraj Ali Khan ,&nbsp;Majid Khan","doi":"10.1016/j.chaos.2025.116553","DOIUrl":"10.1016/j.chaos.2025.116553","url":null,"abstract":"<div><div>The theoretical analysis of photonic spin Hall shift is investigated in gain-assisted four-level N-type dielectric atomic medium. The probe light interacts with a cavity filled with a four-level gain assisted atomic medium. The photonic spin shift tuned to positive and negative value at driving fields parameters. The high value of the photonic spin shift varies in the range of <span><math><mrow><mo>±</mo><mn>60</mn><mi>λ</mi><mo>≤</mo><msubsup><mrow><mi>δ</mi></mrow><mrow><mi>p</mi></mrow><mrow><mi>L</mi><mo>,</mo><mi>R</mi></mrow></msubsup><mo>≤</mo><mo>±</mo><mn>100</mn><mi>λ</mi></mrow></math></span> with the detuning of probe field, while the minimum value of the photonic spin shift varies in the range <span><math><mrow><mo>±</mo><mn>3</mn><mi>λ</mi><mo>≤</mo><msubsup><mrow><mi>δ</mi></mrow><mrow><mi>p</mi></mrow><mrow><mi>L</mi><mo>,</mo><mi>R</mi></mrow></msubsup><mo>≤</mo><mo>±</mo><mn>10</mn><mi>λ</mi></mrow></math></span> with Rabi frequency of the control field. The reported results have useful applications including sensing technology, spintronics, magnetic memory, quantum computing and optical communication.</div></div>","PeriodicalId":9764,"journal":{"name":"Chaos Solitons & Fractals","volume":"198 ","pages":"Article 116553"},"PeriodicalIF":5.3,"publicationDate":"2025-05-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144071234","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Controlling second-order rogue matter wave and line bright soliton dynamics in 2D Bose–Einstein Condensate with higher-order interactions and gain/loss atoms","authors":"Cyrille Edgard Nkenfack ,&nbsp;Olivier Tiokeng Lekeufack ,&nbsp;Subramaniyan Sabari ,&nbsp;Rene Yamapi ,&nbsp;Timoleon Crepin Kofane","doi":"10.1016/j.chaos.2025.116534","DOIUrl":"10.1016/j.chaos.2025.116534","url":null,"abstract":"<div><div>We investigate the two-dimensional modified Gross–Pitaevskii equation, accounting for the effects of atom gain/loss and a time-independent isotropic confining potential, utilizing the Hirota’s bilinear method. Through an appropriate bilinear form, we derive exact one-soliton and multi-soliton solutions. These solutions showcase two prominent phenomena: the second-order rogue matter wave with spatio-temporal localization, and the line soliton with double spatial localization. We demonstrate the feasibility of controlling the soliton amplitude and the effects of gain/loss resulting in areas of collapse by suitably tuning the coefficient of higher-order interactions in the Bose–Einstein condensate. Additionally, by exploring the interaction dynamics of the multi-soliton solutions, we identify elastic-type interactions, claiming the intrinsic properties of solitons. The influence of higher-order interactions and gain/loss terms on the interaction dynamics is also thoroughly analyzed. These analyses demonstrate that, within the framework of Bose–Einstein condensates described by the two-dimensional modified Gross–Pitaevskii equation, higher-order interactions provide a means to control the properties of the generated rogue matter waves. Intensive numerical simulations are performed and their convergence with theoretical predicted results then throw light about the emergent features of the chosen solutions. The exact analytical solutions derived in this study rigorously satisfy the original equation, which ensures their consistency with the numerical results and confirms their accuracy. Thus, our findings hold promise for potential future applications.</div></div>","PeriodicalId":9764,"journal":{"name":"Chaos Solitons & Fractals","volume":"198 ","pages":"Article 116534"},"PeriodicalIF":5.3,"publicationDate":"2025-05-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144071233","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Stochastic dynamics of hysteresis systems under harmonic and Poisson excitations","authors":"Zi Yuan ,&nbsp;Lincong Chen ,&nbsp;Jian-Qiao Sun","doi":"10.1016/j.chaos.2025.116540","DOIUrl":"10.1016/j.chaos.2025.116540","url":null,"abstract":"<div><div>Hysteresis, a common nonlinear phenomenon in engineering structures, has been extensively studied. However, the nonlinear behavior of hysteretic systems under combined deterministic and random excitations remains insufficiently explored. This paper investigates the stochastic response and P-bifurcation of hysteretic systems under harmonic and Poisson white noise excitations. The generalized Fokker–Planck–Kolmogorov (GFPK) equation governing the probability density function (PDF) of the system is solved using a radial basis function neural network (RBFNN) method. Specifically, the trial solution of the GFPK equation is represented by a set of standard Gaussian functions. The loss function incorporates both the residual of the GFPK equation and a normalization constraint. Optimization of the weighting coefficients is transformed into solving a system of algebraic equations, which significantly accelerates the training process. The resulting PDF solutions are used to reveal stochastic P-bifurcation phenomena in both Bouc–Wen and integrable Duhem hysteretic systems. Bifurcation shifts are observed as the random excitation transitions from Poisson to Gaussian noise. The proposed approach is validated by close agreement with Monte Carlo simulation (MCS) results, demonstrating its effectiveness for analyzing complex stochastic dynamics under combined harmonic and non-Gaussian excitations.</div></div>","PeriodicalId":9764,"journal":{"name":"Chaos Solitons & Fractals","volume":"198 ","pages":"Article 116540"},"PeriodicalIF":5.3,"publicationDate":"2025-05-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144067209","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Isochronous and period-doubling diagrams for symplectic maps of the plane","authors":"T. Zolkin ,&nbsp;S. Nagaitsev ,&nbsp;I. Morozov ,&nbsp;S. Kladov ,&nbsp;Y.-K. Kim","doi":"10.1016/j.chaos.2025.116513","DOIUrl":"10.1016/j.chaos.2025.116513","url":null,"abstract":"<div><div>Symplectic mappings of the plane serve as key models for exploring the fundamental nature of complex behavior in nonlinear systems. Central to this exploration is the effective visualization of stability regimes, which enables the interpretation of how systems evolve under varying conditions. While the area-preserving quadratic Hénon map has received significant theoretical attention, a comprehensive description of its mixed parameter-space dynamics remain lacking. This limitation arises from early attempts to reduce the full two-dimensional phase space to a one-dimensional projection, a simplification that resulted in the loss of important dynamical features. Consequently, there is a clear need for a more thorough understanding of the underlying qualitative aspects.</div><div>This paper aims to address this gap by revisiting the foundational concepts of reversibility and associated symmetries, first explored in the early works of G.D. Birkhoff. We extend the original framework proposed by Hénon by adding a period-doubling diagram to his isochronous diagram, which allows to represents the system’s bifurcations and the groups of symmetric periodic orbits that emerge in typical bifurcations of the fixed point. A qualitative and quantitative explanation of the main features of the region of parameters with bounded motion is provided, along with the application of this technique to other symplectic mappings, including cases of multiple reversibility. Modern chaos indicators, such as the Reversibility Error Method (REM) and the Generalized Alignment Index (GALI), are employed to distinguish between various dynamical regimes in the mixed space of variables and parameters. These tools prove effective in differentiating regular and chaotic dynamics, as well as in identifying twistless orbits and their associated bifurcations. Additionally, we discuss the application of these methods to real-world problems, such as visualizing dynamic aperture in accelerator physics, where our findings have direct relevance.</div></div>","PeriodicalId":9764,"journal":{"name":"Chaos Solitons & Fractals","volume":"198 ","pages":"Article 116513"},"PeriodicalIF":5.3,"publicationDate":"2025-05-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144067187","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Particle separation using surface acoustic waves based on microfluidic chip","authors":"Wenbo Han,&nbsp;Hongyuan Zou,&nbsp;Haoyu Yue,&nbsp;Yuhang Zhong,&nbsp;Wei Li,&nbsp;Cunyou Zhang,&nbsp;Hongpeng Zhang","doi":"10.1016/j.chaos.2025.116557","DOIUrl":"10.1016/j.chaos.2025.116557","url":null,"abstract":"<div><div>Surface acoustic wave (SAW)-based microfluidic particle separation offers exceptional biocompatibility and precision for biological applications. This study establishes a multiphysics coupling model integrating piezoelectric dynamics, acoustic-structural interactions, and fluid-particle mechanics to optimize SAW separator design. Systematic analysis of interdigital transducer geometry and flow-acoustic coupling reveals that electrode width governs acoustic wavelength distribution, with 50 μm electrodes achieving optimal pressure gradients. Increasing electrode pairs (N = 5) enhances acoustic pressure inversion, while applied voltage (20 V) proportionally amplifies radiation forces. Notably, channel height exhibits negligible impact on the acoustic field. The optimized device achieves efficient separation of 5–15 μm particles through synergistic flow focusing and acoustic node alignment. This work provides a systematic framework for high-purity biological particle separation, advancing SAW-based microfluidics in diagnostics and cellular analysis.</div></div>","PeriodicalId":9764,"journal":{"name":"Chaos Solitons & Fractals","volume":"198 ","pages":"Article 116557"},"PeriodicalIF":5.3,"publicationDate":"2025-05-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144067208","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}