The European Physical Journal B最新文献

{"title":"Traffic flow dynamics and oscillation control in conserved fractal networks","authors":"Muskan Verma,&nbsp;Arvind Kumar Gupta,&nbsp;Sapna Sharma","doi":"10.1140/epjb/s10051-024-00808-y","DOIUrl":"10.1140/epjb/s10051-024-00808-y","url":null,"abstract":"<p>Traffic control serves as an indispensable component in optimizing the traffic flow, especially on networks. To analyze the varied complexity of traffic dynamics, the percolation backbone fractal network is characterized via cell-transmission model. Taking into account a generalized flow-density relation, dynamic model is modified to scrutinize the impact of transition rates on traffic flow in a conserved network. The macroscopic fundamental diagrams attained through numerical simulation are investigated for homogeneous as well as heterogeneous transition rates. For first-generation fractal network, unimodal or bimodal traffic currents are observed with respect to mean density. Further, for second-generation fractal network, two types of density waves are observed depending upon the number of vehicles present in system: uniform equilibrium state and oscillatory state. It is reported that the transition rates corresponding to singly connected nodes can control the traffic dynamics to ensure a uniform stationary flow, which cannot be achieved via the doubly connected and quadruple-connected nodes.</p>","PeriodicalId":787,"journal":{"name":"The European Physical Journal B","volume":"97 10","pages":""},"PeriodicalIF":1.6,"publicationDate":"2024-10-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1140/epjb/s10051-024-00808-y.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142519143","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":"Probing electron localization and delocalization in the selective long-range tight-binding model","authors":"Mohammad Pouranvari","doi":"10.1140/epjb/s10051-024-00802-4","DOIUrl":"10.1140/epjb/s10051-024-00802-4","url":null,"abstract":"<p>In this study, we perform a detailed investigation into the interplay between disorder-induced electron localization and long-range hopping amplitudes within the Selective Long-Range Tight-Binding Model (SLRTB). Through numerical simulations, we analyze the electronic properties of the system, with a focus on the participation ratio (PR), entanglement entropy (EE), energy spectrum, and the ratio of level spacings (<span>(r_n)</span>). Our results reveal a marked distinction between negative and positive long-range hopping amplitudes, manifesting in different electronic behaviors and transitions. Notably, we carry out a finite-size scaling analysis, identifying the critical point and exponents that characterize the system’s behavior near the transition. The investigation highlights the role of gapless regions in shaping the system’s PR, <span>(r_n)</span>, and EE, and the influence of disorder on these properties. The SLRTB model proves to be an effective framework for understanding the effects of disorder and long-range hopping on electron dynamics, offering valuable insights into localization and delocalization phenomena.</p>","PeriodicalId":787,"journal":{"name":"The European Physical Journal B","volume":"97 10","pages":""},"PeriodicalIF":1.6,"publicationDate":"2024-10-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142518515","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":"Hidden attractors in fractional-order discrete maps","authors":"Vaibhav Varshney,&nbsp;S. Leo Kingston,&nbsp;Sabarathinam Srinivasan,&nbsp;Suresh Kumarasamy","doi":"10.1140/epjb/s10051-024-00780-7","DOIUrl":"10.1140/epjb/s10051-024-00780-7","url":null,"abstract":"<p>This study investigates the hidden dynamics of fractional-order discrete two-dimensional maps, focusing on the generation of hidden attractors and the impact of order on their size and boundaries. Three different nonlinear maps are used, and various measures, such as phase portraits, bifurcation diagrams, and basin of attraction, are presented. This study also observes changes in basin boundaries of hidden attractors with varying order. The rational memristive maps exhibit a well-defined basin of attraction for a broad range of system orders, with multistability and a riddled basin for some orders. The memristive Gauss map also shows well-defined and riddled basins, however, the quadratic chaotic map demonstrates a decreasing basin size and a riddled basin boundary for higher orders of the system.</p>","PeriodicalId":787,"journal":{"name":"The European Physical Journal B","volume":"97 10","pages":""},"PeriodicalIF":1.6,"publicationDate":"2024-10-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142453069","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":"Diffusion on assortative networks: from mean-field to agent-based, via Newman rewiring","authors":"L. Di Lucchio,&nbsp;G. Modanese","doi":"10.1140/epjb/s10051-024-00797-y","DOIUrl":"10.1140/epjb/s10051-024-00797-y","url":null,"abstract":"<p>In mathematical models of epidemic diffusion on networks based upon systems of differential equations, it is convenient to use the heterogeneous mean field approximation (HMF) because it allows to write one single equation for all nodes of a certain degree <i>k</i>, each one virtually present with a probability given by the degree distribution <i>P</i>(<i>k</i>). The two-point correlations between nodes are defined by the matrix <i>P</i>(<i>h</i>|<i>k</i>), which can typically be uncorrelated, assortative or disassortative. After a brief review of this approach and of the results obtained within this approximation for the Bass diffusion model, in this work, we look at the transition from the HMF approximation to the description of diffusion through the dynamics of single nodes, first still with differential equations, and then with agent-based models. For this purpose, one needs a method for the explicit construction of ensembles of random networks or scale-free networks having a pre-defined degree distribution (configuration model) and a method for rewiring these networks towards some desired or “target” degree correlations (Newman rewiring). We describe Python-NetworkX codes implemented for the two methods in our recent work and compare some of the results obtained in the HMF approximation with the new results obtained with statistical ensembles of real networks, including the case of signed networks.</p>","PeriodicalId":787,"journal":{"name":"The European Physical Journal B","volume":"97 10","pages":""},"PeriodicalIF":1.6,"publicationDate":"2024-10-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142453070","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":"Single-photon stimulated emission in waveguide quantum electrodynamics","authors":"O. A. Chuikin,&nbsp;Ya. S. Greenberg,&nbsp;A. A. Shtygashev,&nbsp;A. G. Moiseev","doi":"10.1140/epjb/s10051-024-00784-3","DOIUrl":"10.1140/epjb/s10051-024-00784-3","url":null,"abstract":"<p>We study the scattering of a single-photon pulse from quantum two-level system (qubit) coupled to a continuum spectrum of modes in a one-dimensional (1D) nanophotonic waveguide. We consider two different cases—single-excitation subspace, when photon is incident on a qubit in the ground state, and two-excitation subspace, when photon is incident on excited qubit. For both cases, we find the spatial distribution of photon fields inside a waveguide and derive a time-dependent analytical solution for qubit and photon amplitudes, which can be used to obtain probabilities to find excited qubit and forward or backward moving photons in different configurations. We find that incident wave has much higher probability to be transmitted through the excited qubit which is a signature of single-photon stimulated emission. This property together with a fact that a qubit in the ground state almost completely reflects resonant photons, which can be used to develop method to detect qubit state in an open waveguide. By analyzing two-photon amplitudes for photon incident on excited qubit, we show clear evidence of stimulated emission. Calculations are performed for two initial states of incident photon: plane wave and Gaussian pulse.</p>","PeriodicalId":787,"journal":{"name":"The European Physical Journal B","volume":"97 10","pages":""},"PeriodicalIF":1.6,"publicationDate":"2024-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142447351","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":"The charge states in polypropylene doped with ZrO2 nanoparticles and their changes at heat treatment","authors":"Hijran S. Ibrahimova,&nbsp;Tahir D. Ibragimov","doi":"10.1140/epjb/s10051-024-00801-5","DOIUrl":"10.1140/epjb/s10051-024-00801-5","url":null,"abstract":"<p>Charge states of polypropylene doped with zirconium oxide nanoparticles and their changes during heat treatment at different temperatures are studied by the method of thermally stimulated depolarization (TSD) current. It is shown that two peaks associated with the release of charge from different types of traps appear on the TSD thermograms for both pure polypropylene and composites. With an increase in the concentration of the filler, the intensity of the peaks increases up to 3 vol.%. A further increase in concentration leads to a decrease in the intensity of the peaks. The activation energy of charge release from traps, temperature of maximum of the peaks, and the magnitude of the accumulated charge in the traps have also maximal value at nanoparticle concentration of 3 vol.%. The study of charge characteristics of the nanocomposite with concentration of 3 vol.% after heat treatment shows that the intensity of TSD peaks, the temperature of peak maxima, and the activation energy of charge release increase with increasing pre-treatment temperature. The magnitude of the charge accumulated in traps at low treatment temperatures is practically unchanged but has a maximal value at treatment temperature of 140 °C owing to the increase in the number of traps.</p>","PeriodicalId":787,"journal":{"name":"The European Physical Journal B","volume":"97 10","pages":""},"PeriodicalIF":1.6,"publicationDate":"2024-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142447296","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":"Fuels: a key factor to influence the luminescence properties of CaAl2O4: Dy phosphors","authors":"Kabita Ku. Satapathy,&nbsp;Satya N. Tripathy","doi":"10.1140/epjb/s10051-024-00799-w","DOIUrl":"10.1140/epjb/s10051-024-00799-w","url":null,"abstract":"<div><p>Most commercially available phosphors are made from appropriately doped polycrystalline materials while the activation methods have often been examined, the impact of fuels on the host preparation and its effect on the final performance of the products has received less focus. This paper explores the use of various fuels in the synthesis of Dy-doped CaAl₂O₄ phosphors. Dysprosium-doped monoclinic CaAl₂O₄ phosphors were obtained at low temperatures (500 °C) by the process of combustion of the corresponding metal nitrate–fuel mixtures, over a period of 5 min. In this paper, attention has been paid to the influence of fuels on the luminescence properties of the phosphor sample which is prepared by solution combustion method. Dy-activated CaAl₂O₄ phosphor was synthesized by combustion technique using hydrazine, carbohydrazide, and urea as fuels. XRD analysis reveals that introducing a small quantity of rare earth ions into the raw materials did not alter the crystal structure of CaAl₂O₄. XRD result confirms the formation of the sample. Photoluminescence (PL) emission spectrum showed characteristic emission of Dy doped in the CaAl₂O₄ samples. The highest photoluminescence intensity was observed at a 0.02 mol% concentration of Dy. The PL spectrum exhibits wide peaks near 488 and 573 nm when excited at 347 nm. Mechanoluminescence (ML) and Thermoluminescence (TL) properties of the material have been emphasized. Various ML and TL curves have been recorded to assess which of the fuels yields the most efficient CaAl₂O₄: Dy compound. The prepared sample may be useful in TL dosimetry. In the present investigation it is found that urea is a better fuel for preparing CaAl₂O₄: Dy phosphors and enhances the ML and TL intensity of the sample.</p><h3>Graphical abstract</h3><p>PL emission spectra of CaAl2O4: Dy phosphors synthesized by urea, carbohydrazide and hydrazine, where urea provides the highest PL intensity, making it an optimal choice for enhancing optical performance.</p><div><figure><div><div><picture><img></picture></div></div></figure></div></div>","PeriodicalId":787,"journal":{"name":"The European Physical Journal B","volume":"97 10","pages":""},"PeriodicalIF":1.6,"publicationDate":"2024-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1140/epjb/s10051-024-00799-w.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142443172","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":"Insights from microcanonical thermostatistics into amylin analogues and amyloid-({upbeta }) cross-seeding","authors":"Rafael B. Frigori","doi":"10.1140/epjb/s10051-024-00796-z","DOIUrl":"10.1140/epjb/s10051-024-00796-z","url":null,"abstract":"<p>Growing evidence from population studies and clinical observations strongly suggests a complex connection between major proteinopathies, to know, Type 2 diabetes (T2D) and Alzheimer’s disease (AD). People with T2D face a significantly higher risk of developing AD compared to those without diabetes. These two conditions share several key features, such as inflammation, oxidative stress, metabolic dysfunction, and the buildup of certain proteins known as beta-amyloid (A<span>(upbeta )</span>42) and pancreatic islet amyloid polypeptide (IAPP or amylin). In AD, the brain develops characteristic senile plaques mainly composed of A<span>(upbeta )</span>42. Similarly, in individuals with T2D, the pancreas shows deposits of a protein called human amylin (hIAPP). The accumulation of these aggregated proteins in both the brain and pancreas has been associated with impaired cell function and even cell death. To gain molecular insight in the outset of such complex scenario, we perform microcanonical thermostatistics analysis of Monte Carlo simulations of A<span>(upbeta )</span>42 cross-seeded by hIAPP, or its biotechnological therapeutic analogous as Pramlintide. We find that while A<span>(upbeta )</span>42 is quite prone to cross-seed with hIAPP, and then to aggregate around that critical nuclei, this can be abolished for some of its analogues, which may possibly lead to alternative therapeutic approaches to T2D and AD.</p>","PeriodicalId":787,"journal":{"name":"The European Physical Journal B","volume":"97 10","pages":""},"PeriodicalIF":1.6,"publicationDate":"2024-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142443248","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":"Majorana bound states and phase transitions in first- and second-order topological superconductors","authors":"Xiang-Nan Yuan,&nbsp;Yue Xie,&nbsp;Guo-Qiao Zha","doi":"10.1140/epjb/s10051-024-00800-6","DOIUrl":"10.1140/epjb/s10051-024-00800-6","url":null,"abstract":"<p>Based on the spin-generalized Bogoliubov–de Gennes theory, we investigate the existence of first- and second-order topological phases in Rashba superconducting ribbon and loop systems. The topological phase transitions driven by the strength of spin-orbit coupling and the spin correlation as well as the temperature are demonstrated. The formation of zero-energy Majorana edge or corner states is highly sensitive to these effects. Due to the modification of the relative strength of competing <i>s</i>- and <i>d</i>-wave pairing symmetries, the number and location of Majorana zero modes in the square loop may be tuned by the introduced spin correlation. Meanwhile, the second-order topological phase and emergent Majorana corner modes can remain robust for finite temperatures. We expect that our theoretical predictions may provide useful information for future experiments.</p>","PeriodicalId":787,"journal":{"name":"The European Physical Journal B","volume":"97 10","pages":""},"PeriodicalIF":1.6,"publicationDate":"2024-10-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142434735","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":"Heterogeneous hypergraph representation learning for link prediction","authors":"Zijuan Zhao,&nbsp;Kai Yang,&nbsp;Jinli Guo","doi":"10.1140/epjb/s10051-024-00791-4","DOIUrl":"10.1140/epjb/s10051-024-00791-4","url":null,"abstract":"<p>Heterogeneous graph representation learning gains popularity due to its powerful capabilities of feature extraction and numerous related algorithms have emerged for various downstream tasks in graph structural datasets. However, the interactions among nodes for the heterogeneous graphs in the real world often extend beyond individual pairs, excessive attention is payed on isolated pairwise connections. In this paper, we propose a novel framework of Heterogeneous Hypergraph Representation Learning method (HHRL) to capture high-order interactions for learning effective node representations of heterogeneous graphs. The method firstly organizes the heterogeneous connections as different hypergraphs. By modeling the heterogeneous connections, HHRL captures the rich structural and semantic information present in the graphs. Then, the graph neural network (GNN) is applied for each hypergraph to capture the interdependencies between nodes and their associated features. By utilizing GNN, HHRL can effectively learn expressive node representations that encode both the structural and feature information of the network. Finally, we concatenate the vectors from different hypergraphs to obtain the link representations. The experiments are conducted on five real dataset for link prediction and the results demonstrate the well performance of the proposed framework comparing to the existing baselines</p>","PeriodicalId":787,"journal":{"name":"The European Physical Journal B","volume":"97 10","pages":""},"PeriodicalIF":1.6,"publicationDate":"2024-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142411144","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}