The European Physical Journal B最新文献

{"title":"Spin Hall effect in monolayer black phosphorus","authors":"Yiqing Zhao,&nbsp;Xiaoying Zhou","doi":"10.1140/epjb/s10051-026-01174-7","DOIUrl":"10.1140/epjb/s10051-026-01174-7","url":null,"abstract":"<p>Monolayer black phosphorus (BP), characterized by its direct band gap, high carrier mobility, and pronounced in-plane anisotropy, offers a versatile platform for next-generation nanoelectronic devices. Despite the symmetry-enforced vanishing Berry curvature due to the coexistence of inversion and time-reversal symmetries, we demonstrate that monolayer BP hosts a spin-resolved Berry curvature that drives the intrinsic spin Hall effect. Using a four-band <span>(textbf{k} cdot textbf{p})</span> Hamiltonian, we analytically derive the spin-resolved Berry curvature and the orbital magnetic moment. Both quantities peak at the <span>(Gamma )</span> point and exhibit significant anisotropy, decaying more rapidly along the <span>(k_y)</span> direction than the <span>(k_x)</span> direction. Furthermore, the spin Hall conductivity displays a plateau within the band gap that remains robust against temperature fluctuations due to BP’s large energy gap. Finally, we identify a finite circular polarization along the <span>(k_x)</span> direction as a potential experimental signature for detecting this spin-resolved Berry curvature. Our results establish monolayer BP as a promising candidate for spintronics.</p>","PeriodicalId":787,"journal":{"name":"The European Physical Journal B","volume":"99 5","pages":""},"PeriodicalIF":1.7,"publicationDate":"2026-05-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147829780","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":"Retrieval properties of attractor neural networks with regulated levels of activity","authors":"Kwang Song Ryu,&nbsp;Song Il Om,&nbsp;Kwang Il Ryom,&nbsp;Yong Hae Ko","doi":"10.1140/epjb/s10051-026-01163-w","DOIUrl":"10.1140/epjb/s10051-026-01163-w","url":null,"abstract":"<div><p>As a special case of the Potts model of cortical dynamics, we study a network of McCulloch–Pitts neurons which can be considered as Potts units with only one active state (<i>S</i> = 1). We add anti-symmetric Gaussian noise to the Hebbian component of the interaction matrix, and introduce an extra term in the dynamics of the network in order to constrain its mean activity around a prescribed level. We have investigated maximal storage capacity, basin of attraction and distribution of metastable states in terms of mean-field theory as well as computer simulations. When we constrain the mean activity of the network, maximal storage capacity improves but by tiny amount, while the basin of attraction shrinks a lot. The retrieval band and bandgap of metastable states become wider upon constraining the mean activity. When we introduce asymmetry into the interaction matrix, basin of attraction shrinks a little while the total number of metastable states decreases. Given that constraining mean activity increases storage capacity by several orders of magnitude for the Potts model with <i>S</i> &gt; 1, our results show that the network with <i>S</i> = 1 behaves quite differently in terms of retrieval dynamics.</p><h3>Graphical abstract</h3><div><figure><div><div><picture><source><img></source></picture><span>The alternative text for this image may have been generated using AI.</span></div></div></figure></div></div>","PeriodicalId":787,"journal":{"name":"The European Physical Journal B","volume":"99 5","pages":""},"PeriodicalIF":1.7,"publicationDate":"2026-05-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147829079","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":"Nonreciprocal excitations in magnon–phonon hybrid systems: application to collinear antiferromagnets under zigzag and honeycomb structures","authors":"Shota Sukawa,&nbsp;Satoru Hayami","doi":"10.1140/epjb/s10051-026-01172-9","DOIUrl":"10.1140/epjb/s10051-026-01172-9","url":null,"abstract":"<p>Coupling between magnons and phonons provides a promising pathway toward the realization of phononic diodes and other nonreciprocal phononic functionalities. In this work, we theoretically explore how magnon–phonon hybridization influences elementary excitations in collinear antiferromagnets hosting magnetic toroidal moments. By formulating the full magnon–phonon Hamiltonian and performing numerical diagonalization within the framework of linear spin-wave theory for zigzag and honeycomb structures, we show that the presence of Dzyaloshinskii–Moriya interactions or bond-dependent exchange anisotropy induces nonreciprocity not only in magnon branches but also in phonon modes through their hybridization. Furthermore, we find that the magnitude of phonon nonreciprocity is strongly controlled by the strength of the magnon–phonon coupling. Our results provide a microscopic mechanism for engineering nonreciprocal phononic excitations in magnetic materials characterized by magnetic toroidal moments.</p>","PeriodicalId":787,"journal":{"name":"The European Physical Journal B","volume":"99 5","pages":""},"PeriodicalIF":1.7,"publicationDate":"2026-05-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147829513","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":"Exploring and controlling topological phases in the square-hexagon lattice via Rashba spin-orbit coupling and next-nearest-neighbor hopping","authors":"GuoXiang Wang","doi":"10.1140/epjb/s10051-026-01153-y","DOIUrl":"10.1140/epjb/s10051-026-01153-y","url":null,"abstract":"<p>Based on the tight-binding model, we systematically investigate the influence of the Rashba spin-orbit coupling and the next-nearest-neighbor (NNN) hopping on the topological properties of the square-hexagon lattice. The <span>(Z_2)</span> topological invariant is evaluated numerically via the Fukui–Hatsugai approach. By tracing the evolution of the band gap as functions of the NNN hopping and Rashba spin-orbit coupling (<span>(t_1 - lambda _{R} )</span> and <span>(t_2 - lambda _{R} )</span>), we construct comprehensive phase diagrams. Our findings demonstrate that the interplay between the NNN hopping and Rashba spin-orbit coupling can induce topological phase transitions, including transitions between topological insulator (TI) and normal insulator, as well as between TI and metallic state. In the <span>(t_1 - lambda _{R} )</span> or <span>(t_2- lambda _{R} )</span> phase diagram, topological phases can be achieved almost for all the filling fractions. To further clarify the topological properties of the system, we compute the edge state spectra and provide a detailed analysis of their distinguishing characteristics in both topological trivial and nontrivial phases. Our work demonstrates the rich topological phase behavior in the square-hexagon lattice under the NNN hopping and Rashba spin-orbit coupling, offering theoretical insights for the design and control of topological states in low-dimensional quantum materials.</p>","PeriodicalId":787,"journal":{"name":"The European Physical Journal B","volume":"99 5","pages":""},"PeriodicalIF":1.7,"publicationDate":"2026-05-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147829377","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":"Finite-size scaling properties of classical random walk on various two-dimensional lattices","authors":"Nimish Sharma,&nbsp;Tanay Nag","doi":"10.1140/epjb/s10051-026-01169-4","DOIUrl":"10.1140/epjb/s10051-026-01169-4","url":null,"abstract":"<p>We consider various two-dimensional lattices such as square, Kagome, Lieb, honeycomb, dice lattices of finite extent, to study the effect of lattice profile in terms of the number of nearest neighbour and connectivity patterns on the classical random walk in the unbiased scenario. We find that the standard deviation of distance travelled by the walker i.e., root mean square displacement of the walker is insensitive to the non-uniformity of the lattice profile leading to diffusive transport even in the finite size lattices. We next study the scaling complexity of the entire closed curve traced by the walker while investigating the bulk and boundary fractal dimension namely mass and hull dimensions. Our study indicates that the mass fractal dimension varies within a window <span>(1.50pm 0.03)</span> for all finite-size lattices. A weak ordering within the above window, correlated with the average coordination number, is observed, while Lieb and square lattices yielding the minimum and maximum values, respectively. However, confidence intervals reveal substantial statistical overlap for several lattice pairs even though the lattice profiles vary as far as the average number of connecting bonds and directionality of bonds are concerned. We also study the scaling complexity of the circumference of the closed curve traced by the walker while investigating the hull dimension. We find a similar trend for hull fractal dimension as well and that was found to within the window <span>(1.37pm 0.03)</span> for finite-size lattices. Within the above window, the ordering remains qualitatively unaltered as compared to mass dimension while the confidence interval rectifies the order quantitatively. The square lattice clearly exhibits the upper bound for hull fractal dimension and the remaining lattices show extensive statistical overlap within the above window. We exhibit a tendency of the mass and hull fractal dimension to reach their thermodynamic values given by Brownian motion when we allow more number of steps within the finite size of the lattice, as confirmed by a data collapse analysis. Therefore, our study uncovers the finite-size effect of lattice geometry and co-ordination number on the scaling properties of the path of the random walker.</p>","PeriodicalId":787,"journal":{"name":"The European Physical Journal B","volume":"99 5","pages":""},"PeriodicalIF":1.7,"publicationDate":"2026-05-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147829458","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":"Impact of heavy-tailed synaptic strength distributions on self-sustained activity in networks of spiking neurons","authors":"Ralf Tönjes,&nbsp;Chunming Zheng,&nbsp;Wenping Cui,&nbsp;Benjamin Lindner","doi":"10.1140/epjb/s10051-026-01161-y","DOIUrl":"10.1140/epjb/s10051-026-01161-y","url":null,"abstract":"<p>We analyze states of stationary activity in randomly coupled quadratic integrate-and-fire neurons using stochastic mean-field theory. Specifically, we consider the two cases of Gaussian random coupling and Cauchy random coupling, which are representative of systems with light- or with heavy-tailed synaptic strength distributions. For both, Gaussian and Cauchy coupling, bistability between a low activity and a high activity state of self-sustained firing is possible in excitable neurons. In the system with Cauchy coupling, we find analytically a directed percolation threshold, i.e., above a critical value of the synaptic strength, activity percolates through the whole network starting from a few spiking units only. The existence of the directed percolation threshold is in agreement with previous numerical results in the literature for integrate-and-fire neurons with heavy-tailed synaptic strength distribution. However, we have found that the transition can be continuous or discontinuous, depending on the excitatory–inhibitory imbalance in the network. Networks with Gaussian coupling and networks with Cauchy coupling and additional additive noise lack the percolation transition in the thermodynamic limit.</p>","PeriodicalId":787,"journal":{"name":"The European Physical Journal B","volume":"99 5","pages":""},"PeriodicalIF":1.7,"publicationDate":"2026-05-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1140/epjb/s10051-026-01161-y.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147829268","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":"Self-consistent analysis of the critical temperature shift in layer superconductors","authors":"Nguyen Van Hinh,&nbsp;Le Minh Thu,&nbsp;Bui Duc Tinh","doi":"10.1140/epjb/s10051-026-01171-w","DOIUrl":"10.1140/epjb/s10051-026-01171-w","url":null,"abstract":"<p>We present a self-consistent analysis of the fluctuation-induced shift of the superconducting critical temperature in layered superconductors within the time-dependent Ginzburg–Landau Lawrence–Doniach framework. Using the self-consistent Gaussian approximation, we derive explicit analytical expressions for the shift of the superconducting critical temperature that incorporate the contributions of order parameter fluctuations. Explicit results for two-dimensional and three-dimensional superconductor are also given. We reveal a fundamental dimensional crossover: while the Ginzburg–Levanyuk number <i>Gi</i>, which characterizes the width of the fluctuation-dominated critical region, alone governs the suppression of the critical temperature in three-dimensional (3D) superconductors, the suppression in two-dimensional (2D) and layered superconductors depends additionally on the material’s geometry, namely the layer thickness and interplane spacing. Physically, a reduction in interplane spacing or an increasing in layer thickness suppresses superconducting fluctuations, which in turn diminishes the suppression of the transition temperature. Our theoretical results are consistent with thermodynamic analysis and formulated using experimentally measurable parameters, offering a systematic approach for analyzing fluctuation phenomena in highly anisotropic superconductors and artificially layered materials.</p>","PeriodicalId":787,"journal":{"name":"The European Physical Journal B","volume":"99 5","pages":""},"PeriodicalIF":1.7,"publicationDate":"2026-05-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147802116","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":"Fabricating and controlling the morphological, microstructure and optical features of (CS-PVA-WC-SiO2) promising films for nanoelectronics devices and optical applications","authors":"Wissam Obeis Obaid,&nbsp;Ahmed Hashim,&nbsp;Bahaa H. Rabee","doi":"10.1140/epjb/s10051-026-01170-x","DOIUrl":"10.1140/epjb/s10051-026-01170-x","url":null,"abstract":"<div><p>The current work aims to develop new hybrid nanostructures films to apply in various radiation shielding and optoelectronics nanodevices fields. The tungsten carbide (WC)-silicon dioxide (SiO₂)-doped chitosan (CS)-po1yviny1a1cohol (PVA) new nanocomposites films were fabricated. The (CS-PVA/WC-SiO₂) films exhibit outstanding properties compared to other nanomaterials, including low cost, excellent optical characteristics, flexibility, and lightweight nature. The microstructural, morphological and optical features for CS-PVA/WC-SiO₂ films were investigated. The results indicated that the optical absorbance increased of (85%) and the refractive index increased of (39%) while the optical conductivity (<i>σ</i>) increased of (91%) at wavelength of 320 nm and concentration of (6.6 wt%) WC-SiO₂ nanoparticles. The optical transmittance decreased (39%) at the wavelength of 320 nm and concentration of (6.6 wt%) WC-SiO₂ nanoparticles. At photon energy of 4.78 eV, the absorption coefficient increased (80%) with increasing the concentration of (WC-SiO₂) nanoparticles to (6.6 wt%). The <i>E</i>_g decreases from 4.7 to 3.1 eV for allowed transitions and from 4.3 to 1.7 eV for forbidden transitions when the concentration of WC-SiO₂ nanoparticles rises to 6.6 wt%. The (CS-PVA/WC-SiO₂) films were applied for gamma-ray shielding. These results indicated that the (CS-PVA/WC-SiO₂) films may be considered as promising nanomaterials for optoelectronics and radiation attenuation applications.</p><h3>Graphical abstract</h3>\u0000<div><figure><div><div><picture><source><img></source></picture><span>The alternative text for this image may have been generated using AI.</span></div></div></figure></div></div>","PeriodicalId":787,"journal":{"name":"The European Physical Journal B","volume":"99 5","pages":""},"PeriodicalIF":1.7,"publicationDate":"2026-05-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147829258","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":"Efficient capture of noble gases (Kr, Xe, Rn) on h-ZnX (X = O, S, Se, Te) monolayers: a first-principles study","authors":"Jaouad Ouhrir,&nbsp;Yahya Mekaoui,&nbsp;Zohra Zidane,&nbsp;Mohammed El idrissi,&nbsp;Souad Taj,&nbsp;Bouzid Manaut","doi":"10.1140/epjb/s10051-026-01164-9","DOIUrl":"10.1140/epjb/s10051-026-01164-9","url":null,"abstract":"<p>This study employs first-principles density functional theory (DFT) calculations to systematically investigate the adsorption of noble gases (Kr, Xe, Rn) on hexagonal zinc chalcogenide monolayers h-ZnX ( X = O, S, Se, Te). The structural and electronic properties of the pristine monolayers are first established, confirming their honeycomb structures and reproducing the trend of decreasing band gap from ZnS to ZnTe. Analysis of adsorption energies, equilibrium distances, and charge transfer reveals that h-ZnSe exhibits superior performance for noble gas capture, demonstrating notably strong adsorption energies of <span>(-733)</span> meV for Kr, <span>(-875)</span> meV for Xe, and <span>(-877)</span> meV for Rn. This enhanced affinity is attributed to the favorable electronic configuration and increased polarizability of selenium, which strengthens van der Waals interactions with the large, polarizable noble gas atoms. Density of States (DOS) analysis further corroborates these findings, showing that h-ZnSe provides an optimal electronic environment for interaction, particularly with Rn. The results highlight h-ZnSe as a highly promising two-dimensional material for environmental applications, such as radon mitigation and xenon recovery, demonstrating that chalcogen selection in Zn-based monolayers is an effective strategy for tuning gas-surface interactions.</p>","PeriodicalId":787,"journal":{"name":"The European Physical Journal B","volume":"99 4","pages":""},"PeriodicalIF":1.7,"publicationDate":"2026-04-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147796937","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":"Phase-field crystal simulation of bi-crystal phase and liquid pool evolution in grain boundary premelting region under the strain","authors":"Suleman Muhammad,&nbsp;Yongsheng Li,&nbsp;Iltaf Muhammad,&nbsp;Peng Sang,&nbsp;Zan Zhang","doi":"10.1140/epjb/s10051-026-01165-8","DOIUrl":"10.1140/epjb/s10051-026-01165-8","url":null,"abstract":"<div><p>The phase-field crystal (PFC) model is used to study liquid pools and phase transformations in premelting zones. The investigation reveals distinct transformations, including the conversion of the liquid-triangular-striped phase into triangular phase, the transition from liquid-triangular to triangular phase, and the transformation of triangular-striped phase into striped configurations. Furthermore, the study observes the presence of extensive liquid pools and occurrences of triangular melting. It is shown that grain boundaries alter during premelting with variations of temperature and strain, and the solid phase transforms into the liquid phase at the grain boundaries. We observed that premelting first appears at the grain boundary of a bi-crystal liquid phase due to the aggregation of dislocations and the minimization of free energy over time. A decrease in atomic density and an increase in undercooling contribute to the transition of dislocation arrays, leading to the formation of a liquid-like state with disrupted atomic order. Atom density is inversely proportional to liquid pool width. When a strain is applied, dislocation pairs encounter and form a single crystal as the temperature decreases. It is found that increasing rates accelerate the evolution of liquid pools and dislocation absorption at grain boundaries, promoting lattice distortion and the solid–liquid transition in the premelting zone. These findings reveal that fracture propagation is influenced by strain and undercooling, and the presence of liquid pools in crystal materials also affects fracture propagation. This research holds valuable implications for understanding and controlling phase transformations in various crystals.</p><h3>Graphical Abstract</h3><div><figure><div><div><picture><source><img></source></picture><span>The alternative text for this image may have been generated using AI.</span></div></div></figure></div></div>","PeriodicalId":787,"journal":{"name":"The European Physical Journal B","volume":"99 4","pages":""},"PeriodicalIF":1.7,"publicationDate":"2026-04-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147737894","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}