The European Physical Journal B最新文献

{"title":"Non-hermitian second-order topological superconductor with (s_pm )-wave pairing","authors":"Hao Geng,&nbsp;Xiang Ji,&nbsp;Beibing Huang,&nbsp;Xianqi Tong,&nbsp;Xiaosen Yang","doi":"10.1140/epjb/s10051-025-00983-6","DOIUrl":"10.1140/epjb/s10051-025-00983-6","url":null,"abstract":"<p>Non-Hermitian systems exhibit many exotic phenomena without any Hermitian counterpart, such as the non-Hermitian skin effect, which can fundamentally change the topology of the systems. In this paper, we investigate the topology of the non-Hermitian superconductor with <span>(s_pm )</span>-wave pairing. The study of <span>(s_pm )</span>-wave pairing is crucial for understanding unconventional superconductivity in iron-based materials, as it explains the sign reversal gap driven by spin fluctuations. This mechanism offers insights into other correlated electron systems, such as nickelates under high pressure, and advances the field of high-temperature superconductivity. We explore the topological features of a non-Hermitian superconductor with <span>(s_pm )</span>-wave pairing on a square lattice. We demonstrate that non-Hermitian second-order topological superconductors exhibit unique band collapse behaviors and localized Majorana corner and zero modes under open boundary conditions. Furthermore, we reveal the system’s <span>(Z_2)</span> skin effect, preserving particle-hole symmetry and providing insights into topological phase transitions between non-Hermitian second-order topological superconductors and trivial superconductors.</p>","PeriodicalId":787,"journal":{"name":"The European Physical Journal B","volume":"98 7","pages":""},"PeriodicalIF":1.7,"publicationDate":"2025-07-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145141906","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":"Photoluminescence and magnetic properties of Nd-doped ZnGa₂Se₄","authors":"S. G. Asadullayeva,&nbsp;Z. A. Jahangirli","doi":"10.1140/epjb/s10051-025-00990-7","DOIUrl":"10.1140/epjb/s10051-025-00990-7","url":null,"abstract":"<div><p>This study presents the first investigation of <i>Nd</i>-doped ZnGa₂Se₄, combining experimental analysis through photoluminescence spectroscopy with theoretical ab initio Density Functional Theory (DFT) calculations. Photoluminescence (PL) spectra in the infrared and visible region revealed high-intensity peaks associated with intra-center transitions of neodymium atoms. A comparison with the undoped compound demonstrated that the incorporation of neodymium significantly enhances the emission intensity within the host matrix. The observed spectral variations are primarily attributed to intracenter transitions of <i>Nd</i> ions, energy transfer from the host matrix to these transitions, and crystal field effect. DFT calculation results indicate that <i>Nd</i> preferentially occupies vacancy sites due to the lowest formation energy (− 0.95 eV), aligning with the minimal lattice distortion in this configuration. Total density of states (DOS) and atomic-projected DOS analyses reveal that ZnGa₂Se₄ maintains its semiconducting nature with a bandgap of 2.65 eV, closely matching the experimental value of 2.6 eV. Notably, <i>Nd</i> doping induces magnetic behavior, evidenced by the non-equivalence of spin-up and spin-down states, resulting in a net magnetic moment of 3.79 μB, primarily from <i>Nd-4f</i> and <i>Nd-4d</i> orbitals.</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 7","pages":""},"PeriodicalIF":1.7,"publicationDate":"2025-07-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145141965","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":"γ-ray irradiation effect on the electrical transport properties of Cu films","authors":"Zhaoguo Li,&nbsp;Dawei Yan,&nbsp;Zhiqiang Zhan,&nbsp;Jiangshan Luo,&nbsp;Zhiqing Wu,&nbsp;Fan Lei,&nbsp;Yudan He,&nbsp;Lei Jin,&nbsp;Bo Yang,&nbsp;Qiubo Fu","doi":"10.1140/epjb/s10051-025-00966-7","DOIUrl":"10.1140/epjb/s10051-025-00966-7","url":null,"abstract":"<div><p>We reported the electrical transport properties of Cu films under γ-ray irradiation. The temperature dependence of resistance curves coincides with each other before and after irradiation when the irradiation dose is <span>(lesssim 3.6times {10}^{6} text{rad}(text{Si}))</span>. The resistance of the irradiated Cu film is greater than that of the non-irradiated film across the whole temperature range when the irradiation dose is <span>(gtrsim 3.6times {10}^{7} text{rad}(text{Si}))</span>. This phenomenon is caused by the enhanced surface oxidation effect induced by γ-ray irradiation, and this mechanism has been confirmed by chemical composition analysis. Furthermore, the electrical transport properties of Cu films with and without polyimide coverage were measured during γ-ray irradiation. The experimental results showed that the bare Cu film undergoes surface oxidation, while the Cu film covered by polyimide does not. These results further validate the γ-irradiation enhanced oxidation mechanism in Cu films.</p><h3>Graphical abstract</h3><p>The resistance of the irradiated Cu film greater than that of the non-irradiated film was observed in the whole temperature range when irradiation dose is larger than a critical dose. The physical mechanism of above phenomenon is ascribed to the enhanced surface oxidation effect induced by γ-ray irradiation. The electrical transport properties of Cu films with and without polyimide coverage were also measured during γ-ray irradiation. The experimental results showed that the bare Cu film undergoes surface oxidation, while the Cu film covered by polyimide does not. These results further validate the γ-irradiation enhanced oxidation mechanism in Cu films.</p><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 7","pages":""},"PeriodicalIF":1.7,"publicationDate":"2025-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145141884","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":"Spin-1/2 operators exactly mapped to spinful canonical Fermi operators present in two bands","authors":"Zsolt Gulacsi","doi":"10.1140/epjb/s10051-025-00984-5","DOIUrl":"10.1140/epjb/s10051-025-00984-5","url":null,"abstract":"<div><p>Recently, it has been shown that the quantum spin–1/2 spin operators can be exactly transformed not only in spinless, but also in spinful canonical Fermi operators in 1D [1] and 2D [2] as well. In this paper, using the same technique based on an extended Jordan–Wigner transformation, we show in 1D that the quantum spin-1/2 operators can be exactly transformed also in spinful canonical Fermi operators of spin-1/2 fermions that are belong to two bands.</p></div>","PeriodicalId":787,"journal":{"name":"The European Physical Journal B","volume":"98 7","pages":""},"PeriodicalIF":1.7,"publicationDate":"2025-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1140/epjb/s10051-025-00984-5.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145142127","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":"Structural, electronic and thermoelectric properties of the RENi2 (RE = Dy, Er, Ho) rare Earth intermetallic compounds: a density-functional-theory investigation","authors":"F. Benaddi,&nbsp;A. Bentouaf,&nbsp;A. Azzouz Rached","doi":"10.1140/epjb/s10051-025-00989-0","DOIUrl":"10.1140/epjb/s10051-025-00989-0","url":null,"abstract":"<div><p>This research explores the properties of the RENi₂ (RE = Dy, Er, Ho) intermetallic compounds through a comprehensive study. The investigation employs the FP-LAPW method with the GGA + U calculations to analyze the compounds’ behaviors. The results reveal the metallic behaviors, suggesting the electrical conductivity, and the magnetic properties predominantly originate from the rare earth sublattice. The elastic properties indicate the mechanical stability, and the thermoelectric investigation shows the high thermoelectric power generation potential. The quasi-harmonic Debye model predicts some thermodynamic properties, indicating the high Seebeck coefficients. These findings provide some valuable insights into the materials’ potential applications in the energy storage and spin voltage generators, promoting the advancements in the materials and the energy technologies. Furthermore, the study highlights the relevance of nonlinear physics in the modeling of such materials. Nonlinear exchange–correlation effects, embedded in the DFT formalism, contribute significantly to the observed behaviors. Recent developments in nonlinear theory have provided powerful frameworks for interpreting such properties, especially in systems with strong RE–TM interactions. Relevant contributions can be found in recent works on nonlinear phenomena in strongly correlated materials.</p><h3>Graphical abstract</h3><p>This study investigates RENi₂ (RE = Dy, Er, Ho) intermetallic compounds using the FP-LAPW method with GGA + U calculations, revealing their metallic behavior and magnetic properties originating from the rare earth sublattice. Elastic properties indicate mechanical stability, while thermoelectric analysis shows high power generation potential. The quasi-harmonic Debye model predicts favorable thermodynamic properties, making these compounds promising for energy storage and spin voltage generator applications, advancing materials and energy technologies.</p><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 7","pages":""},"PeriodicalIF":1.7,"publicationDate":"2025-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145141883","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":"A four-terminal thermoelectric heat engine based on three coupled quantum dots","authors":"Quanlin Cao,&nbsp;Jizhou He","doi":"10.1140/epjb/s10051-025-00977-4","DOIUrl":"10.1140/epjb/s10051-025-00977-4","url":null,"abstract":"<div><p>A four-terminal thermoelectric heat engine model based on three capacitively coupled quantum dots is proposed. This system comprises two thermal reservoirs, three interconnected quantum dots, and left/right electron reservoirs. Using master equation theory, we derive analytical expressions for heat flows and electron currents between the quantum dots and their respective reservoirs. Numerical simulations reveal three different operating regimes for which the efficiency is defined as the ratio of power to absorbed heat. We focus on the regime where the heat engine generates output power by utilizing thermal energy from both reservoirs. The effects of key parameters—including temperature gradients, applied voltages, energy levels, and Coulomb charging energies—on the system’s performance are systematically analyzed. Results demonstrate that optimal power output and efficiency at maximum power can be achieved through parameter tuning. This work provides theoretical insights for designing high-performance nanoscale thermoelectric devices.</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 6","pages":""},"PeriodicalIF":1.7,"publicationDate":"2025-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145170672","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":"Investigation of the magneto-electronic, mechanical and transport proprieties of DyFe3N12: DFT computation","authors":"A. Chefa,&nbsp;M. Berrahal,&nbsp;A. Mir,&nbsp;F. Keramsi,&nbsp;Y. Azzaz,&nbsp;A. Bentouaf","doi":"10.1140/epjb/s10051-025-00953-y","DOIUrl":"10.1140/epjb/s10051-025-00953-y","url":null,"abstract":"<div><p>In this work, we performed a theoretical investigation of the DyFe₃Ni₁₂ alloy using the Full-Potential Linearized Augmented Plane Wave (FP-LAPW) method, within the framework of Density Functional Theory (DFT) and the Local Spin Density Approximation (LSDA). The results confirm that DyFe₃Ni₁₂ stabilizes in a cubic crystal structure, and the magnetic stability analysis reveals a ferromagnetic ordering. Furthermore, the calculations of the density of states (DOS) and band structure indicate the metallic nature of the compound. Mechanical stability was also assessed, with calculations of key mechanical parameters supporting its robustness. Thermoelectric estimations suggest that DyFe₃Ni₁₂ holds great promise for applications in spintronics and phonon scattering devices.</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 6","pages":""},"PeriodicalIF":1.7,"publicationDate":"2025-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145169415","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":"Correlation time in extremal self-organized critical models","authors":"Rahul Chhimpa,&nbsp;Abha Singh,&nbsp;Avinash Chand Yadav","doi":"10.1140/epjb/s10051-025-00988-1","DOIUrl":"10.1140/epjb/s10051-025-00988-1","url":null,"abstract":"<p>We investigate correlation time numerically in extremal self-organized critical models, namely the Bak–Sneppen evolution and the Robin Hood dynamics. The (fitness) correlation time is the duration required for the extinction or mutation of species over the entire spatial region in the critical state. We apply the methods of finite-size scaling and extreme value theory to understand the statistics of the correlation time. We find power-law system size scaling behaviors for the mean, the variance, the mode, and the peak probability of the correlation time. We obtain data collapse for the correlation time cumulative probability distribution, and the scaling function follows the generalized extreme value density close to the Gumbel function.</p>","PeriodicalId":787,"journal":{"name":"The European Physical Journal B","volume":"98 6","pages":""},"PeriodicalIF":1.7,"publicationDate":"2025-06-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145170137","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":"Analysis of traffic characteristics in mixed road environments based on a unified lattice hydrodynamic model","authors":"Yanhong Wang,&nbsp;Changcai Zhang,&nbsp;Caihua Zhu,&nbsp;Haoyu Hou,&nbsp;Zhenfeng Wang","doi":"10.1140/epjb/s10051-025-00985-4","DOIUrl":"10.1140/epjb/s10051-025-00985-4","url":null,"abstract":"<div><p>Mountainous urban road networks feature complex geometries, including straight, curved, and sloped segments, which jointly impact traffic dynamics. Given the critical role of traffic stability in ensuring safety and efficiency in such settings, this study examines how road geometry affects traffic stability and flow under minor disturbances. We develop a unified lattice hydrodynamic model integrating straight, curved, and sloped segments, and conduct linear and nonlinear analyses. Our results reveal that roads with a higher proportion of curves and smaller turning radii enhance traffic stability. Conversely, while roads with more curves and larger radii are more vulnerable to disruptions, they enable higher traffic flux. This paradox stems from lower speeds on smaller-radius curves dampening disturbance impacts, whereas higher speeds on larger-radius curves, beneficial for flow, increase traffic sensitivity to perturbations. The study further shows that adjusting road segment proportions, turning radii, and gradients optimizes traffic stability and flow. Numerical simulations validate these findings, and VT-Micro model data confirm that road geometry adjustments reduce fuel consumption and emissions. This research provides practical guidance for mountainous urban road design and offers new insights into traffic management in complex road environments, balancing efficiency and environmental sustainability.</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 6","pages":""},"PeriodicalIF":1.7,"publicationDate":"2025-06-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145169413","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":"Study on the electronic structure and optical properties of InSb/WSSe van der Waals heterostructure","authors":"Su Su,&nbsp;Xinyu Zhao,&nbsp;Xuewen Wang,&nbsp;Xiankui Lv,&nbsp;Weibin Zhang","doi":"10.1140/epjb/s10051-025-00987-2","DOIUrl":"10.1140/epjb/s10051-025-00987-2","url":null,"abstract":"<div><p>Van der Waals heterostructures offer promising avenues for designing optoelectronic materials with tailored functionalities. Here, we employ first-principles calculations to investigate the structure, electronic, and optical properties of a novel InSb/WSSe heterojunction. The optimized structure reveals a stable interlayer spacing of 3.229 Å and exhibits type-II band alignment with a direct bandgap of 0.54 eV. Charge density analyses indicate electron transfer from the InSb layer to WSSe, resulting in an intrinsic interfacial electric field directed from InSb to WSSe. The heterojunction features a work function of 5.12 eV and demonstrates a notable enhancement of 37%. The InSb/WSSe heterojunction effectively combines the optical advantages of its constituent materials. Optical absorption is significantly boosted across the infrared, visible, and near-ultraviolet regions, with peak absorption in the visible spectrum reaching 20.63%—representing 44% increase than the monolayer components. In the infrared region, the absorption rate of the heterojunction breaks through from 0 to 14.96%. In the near-ultraviolet region, absorption improves by 26.6% compared to monolayer WSSe. Moreover, compared to monolayer WSSe, the heterostructure effectively suppresses optical transmittance (84.36%) and exhibits distinctive reflectance peaks. These findings highlight the InSb/WSSe heterojunction as a promising platform for broadband light-harvesting and next-generation optoelectronic applications.</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 6","pages":""},"PeriodicalIF":1.7,"publicationDate":"2025-06-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145167228","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}