Chaos Solitons & Fractals最新文献

{"title":"Solitons and transmission feasibility in piezoelectric semiconductor quantum plasmas","authors":"Abhishek Yadav,&nbsp;Punit Kumar","doi":"10.1016/j.chaos.2025.116589","DOIUrl":"10.1016/j.chaos.2025.116589","url":null,"abstract":"<div><div>A study of coupling of the lattice ion vibrations, with the electron waves in a piezoelectric semiconductor quantum plasma is presented. The nonlinearities have been studied and the solitons have been analyzed. The theory has been built using the quantum hydrodynamic (QHD) model, incorporating the effects of Fermi pressure, quantum Bohm and exchange correlation potentials. The dispersion relation for the coupling has been set up. A set of nonlinear evolution equations has been established using the two-time scale theory and soliton solution for coupled nonlinear evolution equations has been obtained using the modified quantum Zakharov equations. The solitons are found to have a cusp profile. It is also found that soliton's field amplitude increases significantly with particle density and coupling strength in piezoelectric semiconductor quantum plasma.</div></div>","PeriodicalId":9764,"journal":{"name":"Chaos Solitons & Fractals","volume":"198 ","pages":"Article 116589"},"PeriodicalIF":5.3,"publicationDate":"2025-05-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144105991","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":"Topological states in a central-octagon moiré photonic lattice: Edge, corner, and floquet insulator properties","authors":"Sheng Xu ,&nbsp;Zijing Wang ,&nbsp;Peng Li ,&nbsp;Feng Wen ,&nbsp;Yuzong Gu ,&nbsp;Renming Liu ,&nbsp;Zhenkun Wu","doi":"10.1016/j.chaos.2025.116595","DOIUrl":"10.1016/j.chaos.2025.116595","url":null,"abstract":"<div><div>Moiré photonic lattices, created by twisting or superimposing identical periodic sublattices, have attracted considerable interest as flexible platforms for topological photonics. Inspired by the Su–Schrieffer–Heeger model, we systematically investigate edge and corner states in a central-octagon moiré lattice. By discretizing this lattice, we demonstrate that both zigzag and bearded edges support localized modes under specific coupling conditions. Employing an oblique truncation method, we construct a type-II zigzag edge and confirm its topological feature by calculating the bulk polarization, revealing a novel mechanism for topological transport. Furthermore, we discover higher-order corner modes under open boundary conditions, characterized by strong spatial localization. Extending our analysis to Floquet model, we demonstrate that topologically protected edge states persist, exhibiting robustness against structural defects. These findings enhance our understanding of moiré photonic lattices and pave a new way for exploring and utilizing topological phenomena in photonic systems.</div></div>","PeriodicalId":9764,"journal":{"name":"Chaos Solitons & Fractals","volume":"198 ","pages":"Article 116595"},"PeriodicalIF":5.3,"publicationDate":"2025-05-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144105990","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":"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":"Countless coexisting chaotic attractors: From system construction to FPGA-based observation","authors":"Guohao Pan ,&nbsp;Chunbiao Li ,&nbsp;Wangyu Liu ,&nbsp;Yishi Xue ,&nbsp;Xiaolong Qi","doi":"10.1016/j.chaos.2025.116610","DOIUrl":"10.1016/j.chaos.2025.116610","url":null,"abstract":"<div><div>Coexisting chaotic attractors provide much more convenience for the diverse outputs of chaos. At the same time, multistable chaotic systems exhibit strong uncertainty and complexity. Therefore, the chaotic system with multistable states plays an important role in specific application situations. In this paper, a chaotic system is transformed to be the one outputting countless coexisting chaotic attractors by expanding the dimension of the system or embedding the function of the feedback. The introduction of complex feedback contributes to the generation of chaos, while the embedding of fixed functions facilitates the constraints on the offset within the system variables. In this framework, adjusting the linear function constraint relationship between offset-interlocked variables can also regulate the distribution direction of coexisting attractors. The work shows the simple candidates with offset constraints outputting countless coexisting attractors, where some of the system variables with different average values can be triggered through the initial conditions. Based on FPGA, all the phenomenon associated with the coexisting attractors are observed by the initial condition selection.</div></div>","PeriodicalId":9764,"journal":{"name":"Chaos Solitons & Fractals","volume":"198 ","pages":"Article 116610"},"PeriodicalIF":5.3,"publicationDate":"2025-05-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144090625","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":"Pure-quartic soliton pulsating and creeping dynamics in a bidirectional mode-locked fiber laser","authors":"Min Luo ,&nbsp;Ze-Xian Zhang ,&nbsp;Yong Wei ,&nbsp;Liang Luo ,&nbsp;Wen-Jin Wang ,&nbsp;Yu-Jie Kong ,&nbsp;Yu-Yan Tang ,&nbsp;Can Liu ,&nbsp;Jun-Hao Li ,&nbsp;Jia-Hong Jin","doi":"10.1016/j.chaos.2025.116611","DOIUrl":"10.1016/j.chaos.2025.116611","url":null,"abstract":"<div><div>Pure-quartic solitons (PQSs) represent a significant advancement in the field of ultrafast optics, enabling the generation of high-energy pulses. This study presents a systematic numerical investigation of the pulsating and creeping dynamics of PQSs in a bidirectional mode-locked fiber laser, focusing on the influence of fourth-order dispersion (FOD). By carefully adjusting the FOD, distinct pulsating behaviors of PQSs are observed in both clockwise (CW) and counterclockwise (CCW) directions of propagation. However, notable differences in the pulsating amplitudes between the two propagation directions are identified, primarily attributed to the interplay between nonlinear effects and FOD within the laser cavity. Furthermore, as the FOD is increased beyond a certain threshold, PQSs begin to exhibit creeping behavior, characterized by periodic temporal shifts in their pulse dynamics. Importantly, precise control over the creeping distance can be achieved by tuning the FOD. This work also reveals intricate aspects of creeping dynamics, including phenomena such as synchronized and asynchronous creeping periods. These findings not only deepen our understanding of ultrafast optics but also provide both theoretical insights and practical guidance for the application of dual-comb light sources.</div></div>","PeriodicalId":9764,"journal":{"name":"Chaos Solitons & Fractals","volume":"198 ","pages":"Article 116611"},"PeriodicalIF":5.3,"publicationDate":"2025-05-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144090626","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}