The European Physical Journal B最新文献

{"title":"Dual quadratic compound multiswitching anti-synchronization of Lorenz, Rössler, Lü and Chen chaotic systems","authors":"Govind Singh,&nbsp;Dinesh Khattar,&nbsp;Neha Agrawal","doi":"10.1140/epjb/s10051-024-00855-5","DOIUrl":"10.1140/epjb/s10051-024-00855-5","url":null,"abstract":"<p>This paper offers a unique synchronization strategy for synchronizing eight chaotic systems. The new approach is referred to as dual quadratic compound anti synchronization. We additionally employed signal multi-switching to augment the complexity of the suggested technique. In communication theory, the transmission and security of the resulting signal are more effective because of the numerous combinations of chaotic systems and multiswitching that provide such complicated dynamic behavior. To demonstrate the acquired results, Lorenz, Rössler, Lü, and Chen chaotic system are used. Using the Lyapunov stability principle, sufficient conditions are attained and appropriate controllers are built to achieve the required synchronization between eight chaotic systems. To validate the findings from theory, numerical simulations, and graphics are presented using MATLAB.</p>","PeriodicalId":787,"journal":{"name":"The European Physical Journal B","volume":"98 1","pages":""},"PeriodicalIF":1.6,"publicationDate":"2025-01-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142995285","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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}

{"title":"Magnetic and dielectric studies of the La0.8Na0.2Mn0.97Fe0.03O3 sol–gel compound","authors":"M. R. Laouyenne,&nbsp;Mohamed Baazaoui,&nbsp;Fatma Aouaini,&nbsp;Beriham Basha,&nbsp;KholoudSaad Al-mugren","doi":"10.1140/epjb/s10051-024-00857-3","DOIUrl":"10.1140/epjb/s10051-024-00857-3","url":null,"abstract":"<div><p>This research aimed to investigate the magnetic and dielectric phenomena of the La_0.8Na_0.2Mn_0.97Fe_0.03O₃ sol–gel compound. Through the magnetic analysis of <i>M</i> (<i>μ</i>₀<i>H</i>, <i>T</i>), we observed that the compound undergoes a ferromagnetic–paramagnetic phase transition. A perfect coincidence was observed between the magnetic entropy changes calculated using the Maxwell relation and Landau theory only in the high-temperature range. Furthermore, based on the mean field theory, we calculate the number of spins (<i>S</i> = 3) and the saturation magnetization (<i>M</i>_sat = 87emu/g). With these parameters, we computed – Δ<i>S</i>_M at different applied magnetic fields. We have observed an appreciable coincidence between -ΔSM calculated using the Maxwell relation and mean field model, confirming the validity of this technique. This suggests that the phase transition of our compound is completely described by the mean field model. Moving forward, we planned to continue investigating of the compound in our study by the critical phenomena. We calculated the critical exponent values using different approaches, such as Kouvel–Fisher, Modified Arrott plot, and critical isotherm technique. The Banerjee approach confirmed that the phase transition is of second order. We determined that the mean field model is the best description for the transition of La_0.8Na_0.2Mn_0.97Fe_0.03O₃. The determined values are <i>β</i> = 0.43, <i>γ</i> = 1.09 and <i>δ</i> = 3.57. Finally, the total conductivity plots for the sample were established by Jonscher power law. The effect of frequency, temperature on the constant dielectric (<i>ε</i>\") and the dielectric loss (tan <i>δ</i>) has been deliberated in terms of hopping of the charge carriers between Mn³⁺ and Mn⁴⁺ ions. Activation energy has been calculated from both temperature dependence of the continuous conductivity and the relaxation time values that confirm that same kinds of charge carriers are governing both the processes. Nyquist plot of the impedance displays semicircle arcs and the electrical equivalent circuit of the type of RG + (RGB//CPE) has been proposed to explain the impedance results.</p><h3>Graphical abstract</h3>\u0000<div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":787,"journal":{"name":"The European Physical Journal B","volume":"98 1","pages":""},"PeriodicalIF":1.6,"publicationDate":"2025-01-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142995747","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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}

{"title":"Discovering motifs to fingerprint multi-layer networks: a case study on the connectome of C. Elegans","authors":"Deepak Sharma,&nbsp;Matthias Renz,&nbsp;Philipp Hövel","doi":"10.1140/epjb/s10051-024-00848-4","DOIUrl":"10.1140/epjb/s10051-024-00848-4","url":null,"abstract":"<p>Motif discovery is a powerful and insightful method to quantify network structures and explore their function. As a case study, we present a comprehensive analysis of regulatory motifs in the connectome of the model organism <i>Caenorhabditis elegans</i> (<i>C. elegans</i>). Leveraging the Efficient Subgraph Counting Algorithmic PackagE (ESCAPE) algorithm, we identify network motifs in the multi-layer nervous system of <i>C. elegans</i> and link them to functional circuits. We further investigate motif enrichment within signal pathways and benchmark our findings with random networks of similar size and link density. Our findings provide valuable insights into the organization of the nerve net of this well-documented organism and can be easily transferred to other species and disciplines alike.</p>","PeriodicalId":787,"journal":{"name":"The European Physical Journal B","volume":"98 1","pages":""},"PeriodicalIF":1.6,"publicationDate":"2025-01-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1140/epjb/s10051-024-00848-4.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142994922","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Piezo-photothermal wave dynamics in an orthotropic hygrothermal semiconductor exposed to heat and moisture flux","authors":"Kh. Lotfy,&nbsp;Ibrahim S. Elshazly,&nbsp;Borhen Halouani,&nbsp;Saurav Sharma,&nbsp;Eslam S. Elidy","doi":"10.1140/epjb/s10051-024-00852-8","DOIUrl":"10.1140/epjb/s10051-024-00852-8","url":null,"abstract":"<div><p>This study examines the interactions of piezoelectric, photothermal, and thermoelastic wave phenomena in orthotropic semiconductors subjected to thermal regulation via water. This study presents a model for coupling heat and moisture transport alongside photo-hydroelectricity. mechanical deformation induces the piezoelectric effect, initiating carrier density (plasma) waves by generating a polarization charge. At present, photothermal effects, caused by light absorption, facilitate the formation and propagation of plasma waves. The interplay of moisture and temperature under hygrothermal circumstances adds complexity to material behavior, affecting the formation and propagation of plasma waves. The normal mode technique produces analytical formulations for the transient response of temperature variation, moisture distribution, plasma, displacement, and stress components during continuous heat and moisture flow at the semiconductor surface. The research employs advanced mathematical techniques and computational simulations to demonstrate the influence of piezoelectricity, photothermal, and hygrothermal on primary physical field wave propagation. The numerical data is employed to graphically represent and calculate the hygrothermal fields and stress response in photo-hygrothermoelastic materials, including fluctuations in moisture content and time.</p><h3>Graphical abstract</h3>\u0000<div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":787,"journal":{"name":"The European Physical Journal B","volume":"98 1","pages":""},"PeriodicalIF":1.6,"publicationDate":"2025-01-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142995489","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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}

{"title":"Investigations on structural, electronic, magnetic, and optical response of HfXO2 (X = Al/Ga/In) novel materials for optoelectronic applications","authors":"M. Junaid Iqbal Khan,&nbsp;Asif Rasheed,&nbsp;Asifa Iqbal,&nbsp;Javed Ahmad,&nbsp;Zarfishan Kanwal,&nbsp;Imran Taj,&nbsp;Nauman Usmani,&nbsp;Masood Yousaf,&nbsp;Hamid Ullah","doi":"10.1140/epjb/s10051-024-00856-4","DOIUrl":"10.1140/epjb/s10051-024-00856-4","url":null,"abstract":"<div><p>Current research enumerates a density functional theory (DFT) study of Al/Ga/In-doped HfO₂ using the Wien2k code. Spin-polarized calculations illustrate the non-magnetic behavior of HfO₂, whereas evidence of magnetism is found in Al-, Ga-, and In-doped HfO₂. Al@HfO₂ contains a higher magnetic moment of 3.13 <span>({mu }_{text{B}})</span>, while the least value (2.58 <span>({mu }_{text{B}})</span>) is noticed for In@HfO₂ material. The prominent role of Al 3<i>p</i>-, Ga 3<i>d</i>-, and In 4<i>d</i>-states is observed around the Fermi level and helps in improving the electronic properties of proposed materials. Band gap of selected materials is reduced and shows material’s ability for good conduction. Absorption spectra of Al@HfO₂ and Ga@HfO₂ materials exhibit blueshift, but In@HfO₂ shows redshift when compared with pure HfO₂. These materials may have applications in future solar, optoelectronics, energy harvesting, and spintronic devices due to enhanced absorption and conductivity along with decreased reflectivity in the UV region.</p><h3>Graphical abstract</h3><div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":787,"journal":{"name":"The European Physical Journal B","volume":"98 1","pages":""},"PeriodicalIF":1.6,"publicationDate":"2025-01-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142995196","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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}

{"title":"Topological Bardeen–Cooper–Schrieffer theory of superconducting quantum rings","authors":"Elena Landrò,&nbsp;Vladimir M. Fomin,&nbsp;Alessio Zaccone","doi":"10.1140/epjb/s10051-024-00851-9","DOIUrl":"10.1140/epjb/s10051-024-00851-9","url":null,"abstract":"<p>Quantum rings have emerged as a playground for quantum mechanics and topological physics, with promising technological applications. Experimentally realizable quantum rings, albeit at the scale of a few nanometers, are 3D nanostructures. Surprisingly, no theories exist for the topology of the Fermi sea of quantum rings, and a microscopic theory of superconductivity in nanorings is also missing. In this paper, we remedy this situation by developing a mathematical model for the topology of the Fermi sea and Fermi surface, which features non-trivial hole pockets of electronic states forbidden by quantum confinement, as a function of the geometric parameters of the nanoring. The exactly solvable mathematical model features two topological transitions in the Fermi surface upon shrinking the nanoring size either, first, vertically (along its axis of revolution) and, then, in the plane orthogonal to it, or the other way round. These two topological transitions are reflected in a kink and in a characteristic discontinuity, respectively, in the electronic density of states (DOS) of the quantum ring, which is also computed. Also, closed-form expressions for the Fermi energy as a function of the geometric parameters of the ring are provided. These, along with the DOS, are then used to derive BCS equations for the superconducting critical temperature of nanorings as a function of the geometric parameters of the ring. The <span>(T_c)</span> varies non-monotonically with the dominant confinement size and exhibits a prominent maximum, whereas it is a monotonically increasing function of the other, non-dominant, length scale. For the special case of a perfect square toroid (where the two length scales coincide), the <span>(T_c)</span> increases monotonically with increasing the confinement size, and in this case, there is just one topological transition.</p>","PeriodicalId":787,"journal":{"name":"The European Physical Journal B","volume":"98 1","pages":""},"PeriodicalIF":1.6,"publicationDate":"2025-01-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1140/epjb/s10051-024-00851-9.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142994713","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"DFT + U study of chromium-doped europium oxide: insights into half-metallic behavior and stability","authors":"Khadidja Mokaddem,&nbsp;Djillali Bensaid,&nbsp;Bendouma Doumi,&nbsp;Allel Mokaddem,&nbsp;Kaddour Bencherif","doi":"10.1140/epjb/s10051-024-00850-w","DOIUrl":"10.1140/epjb/s10051-024-00850-w","url":null,"abstract":"<div><p>The objective of this work is to apply density functional theory (DFT) with the inclusion of the Coulomb interaction (Hubbard U) to elements that possess d and f orbitals to explore the half-metallic properties of Europium oxide doped with Chromium. The formation energy recommends that these compounds (<span>({text{Eu}}_{1-text{x}}{text{Cr}}_{text{x}}text{O})</span>) are thermodynamically stable and our findings confirm that the introduction of Chromium (Cr) into the Europium Oxide (EuO) host matrix results in the emergence of a band gap in the minority spin channel, validating the half-metallic nature of our materials. Integer Bohr magneton values for total magnetizations confirm the half-metallic ferromagnetic behavior. The value of the half-metallic gap decreases when the concentration is increased. Remarkable results were observed on the EuO compound with the inclusion of Cr d content. The system undergoes a double-exchange mechanism which stabilizes ferromagnetic state. The estimated Curie temperature closely aligns with ambient conditions for concentrations of both 0.25 and 0.75, while reaching 169 K for a concentration of 0.5. These findings motivate further exploration into different concentrations and alternative dopant ions.</p><h3>Graphical abstract</h3><div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":787,"journal":{"name":"The European Physical Journal B","volume":"98 1","pages":""},"PeriodicalIF":1.6,"publicationDate":"2025-01-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142976480","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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}

{"title":"Deciphering complexity: machine learning insights into the chaos","authors":"Lazare Osmanov","doi":"10.1140/epjb/s10051-024-00840-y","DOIUrl":"10.1140/epjb/s10051-024-00840-y","url":null,"abstract":"<p>We introduce new machine learning techniques for analyzing chaotic dynamical systems. The main goal of this study is to develop a simple method for calculating the Lyapunov exponent using only two trajectory data points, in contrast to traditional methods that require averaging procedures. Additionally, we explore phase transition graphs to analyze the shift from regular periodic to chaotic dynamics, focusing on identifying “almost integrable” trajectories where conserved quantities deviate from whole numbers. Furthermore, we identify “integrable regions” within chaotic trajectories. These methods are tested on two dynamical systems: “two objects moving on a rod” and the “Henon–Heiles” system.</p>","PeriodicalId":787,"journal":{"name":"The European Physical Journal B","volume":"98 1","pages":""},"PeriodicalIF":1.6,"publicationDate":"2025-01-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142941180","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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}

{"title":"Optimizing operational parameters for improved photocatalytic activity of hematite–rGO nanocomposites in methylene blue dye degradation","authors":"Anuradha,&nbsp;Arshdeep Singh,&nbsp;Raj Kumar Seth,&nbsp;Praveen Kumar,&nbsp;Sandeep Kumar","doi":"10.1140/epjb/s10051-024-00849-3","DOIUrl":"10.1140/epjb/s10051-024-00849-3","url":null,"abstract":"<div><p>The α-Fe₂O₃/rGO nanocomposites with varying GO concentrations were successfully synthesized utilizing the co-precipitation method followed by annealing. FESEM investigation revealed that the nanocomposites were composed of quasi-spherical α-Fe₂O₃ nanoparticles with an average particle size of 32.77 nm which were distributed on the wrinkled rGO sheets. Further, the elemental mapping of FESEM confirms that carbon is the dominant component with 66.26 at.%. The nanocomposites were studied for degrading methylene blue dye under varying conditions like photocatalyst load, dye concentration, light intensity, and pH. The photocatalyst load of 0.4 g/L gives the best results at the dye concentration of 5.34 µM. On the other hand, as load and dye concentrations increased further, the nanocomposite’s photocatalytic activity reduced. The nanocomposites were also found to be effective in degrading MB dye molecules under high light intensity and alkaline pH. The impact of operational parameters on nanocomposite’s degrading efficiency was examined in depth by contrasting their deterioration rate constant values, which were derived from the Langmuir–Hinshelwood model. Additionally, a suitable mechanism has been mentioned to explain the outcomes of photocatalytic activity. The highest doped nanocomposite with 0.4 g/L load at 5.34 μM initial dye concentration, high light intensity, and pH 12 had the maximum degradation efficiency of 94%.</p><h3>Graphical abstract</h3>\u0000<div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":787,"journal":{"name":"The European Physical Journal B","volume":"98 1","pages":""},"PeriodicalIF":1.6,"publicationDate":"2025-01-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142941058","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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}

{"title":"Spatial and fine energy structure of indirect exciton","authors":"V. P. Dzyuba,&nbsp;O. B. Vitrik","doi":"10.1140/epjb/s10051-024-00841-x","DOIUrl":"10.1140/epjb/s10051-024-00841-x","url":null,"abstract":"<div><p>Quantum states of a spatially indirect exciton (IX), including its binding energy, are largely determined by the geometry of the spatial quantum structure consisting of (IX) and the interface (IXI). Unfortunately, this fact has been poorly studied both experimentally and theoretically. In this paper, the parameters of the IXI geometry and their effect on the IX binding energy spectrum are analytically investigated for the first time. For this purpose, the potential of the Coulomb interaction of an electron and a hole is determined using the image method. It is shown that the geometry parameters are quantized, and the effective permittivity of the interface becomes dependent on the orbital and magnetic quantum numbers of IX. A nonlinear dependence of the IX binding energy on the geometric parameters is observed. All these manifestations of the geometry are accessible to experimental observation. Each geometry has its own quantum states. This opens up the possibility of using IXI in exciton spectroscopy of the interface layer. The controllability of the IXI geometry by polarized light allows us to hope for using quantum geometric states of IX as qubits. In this work, various geometric states IX of two planar heterostructures SiO₂/Si₃N₄ and GaAs/CdSe were modeled as an example.</p><h3>Graphical abstract</h3><div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":787,"journal":{"name":"The European Physical Journal B","volume":"98 1","pages":""},"PeriodicalIF":1.6,"publicationDate":"2025-01-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142939205","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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}