The European Physical Journal B最新文献

{"title":"Characterizing asymmetric and bimodal long-term financial return distributions through quantum walks","authors":"Stijn De Backer,&nbsp;Luis E. C. Rocha,&nbsp;Jan Ryckebusch,&nbsp;Koen Schoors","doi":"10.1140/epjb/s10051-026-01157-8","DOIUrl":"10.1140/epjb/s10051-026-01157-8","url":null,"abstract":"<p>The analysis of logarithmic return distributions defined over large time scales is crucial for understanding the long-term dynamics of asset price movements. For large time scales of the order of two trading years, the anticipated Gaussian behavior of the returns often does not emerge, and their distributions often exhibit a high level of asymmetry and bimodality. These features are inadequately captured by the majority of classical models to address financial time series and return distributions. In the presented analysis, we use a model based on the discrete-time quantum walk to characterize the observed asymmetry and bimodality. The quantum walk distinguishes itself from a classical diffusion process by the occurrence of interference effects, which allows for the generation of bimodal and asymmetric probability distributions. By capturing the broader trends and patterns that emerge over extended periods, this analysis complements traditional short-term models and offers opportunities to more accurately describe the probabilistic structure underlying long-term financial decisions.</p>","PeriodicalId":787,"journal":{"name":"The European Physical Journal B","volume":"99 4","pages":""},"PeriodicalIF":1.7,"publicationDate":"2026-04-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147737594","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":"Tunable quantum oscillations in graphene nanoribbons: from single-mode Fabry–Pérot interference to multi-mode transport","authors":"Fan Wei","doi":"10.1140/epjb/s10051-026-01158-7","DOIUrl":"10.1140/epjb/s10051-026-01158-7","url":null,"abstract":"<div><p>Using the Keldysh Green function formalism, we compute the bond-resolved current on the hexagonal honeycomb lattice of graphene, including next- and third-nearest neighbor hopping, and establish a direct one-to-one correspondence between the spatial patterns of local current oscillations and the oscillatory conductance observed for both electron and hole carriers. At <span>(t'=0.05t)</span>, the <span>(p=pm 2, pm 1,0)</span> conduction subbands lie above the Fermi level of <span>(E_F=2.5,textrm{eV})</span>, supporting five electron-type quantum channels. Applying a potential barrier <span>(U&gt;0)</span> reduces the number of accessible subbands inside the barrier region. Each propagating mode acts as a Fabry-Pérot interferometer, giving rise to decaying periodic oscillations in the conductance, <span>(G=(2e^2/h)sum _i|t_{ii}|^2)</span>. In contrast, applying a well potential <span>(U&gt;0)</span> increases the number of accessible subbands, activating interband transitions. The conductance follows the multimode Landauer formula <span>(G=(2e^2/h)sum _isum _j|t_{ji}|^2)</span>, where <span>(t_{ji})</span> is the transmission amplitude from incident mode <i>i</i> to outgoing mode <i>j</i>. The resulting sum over paths with incommensurate phase factors <span>(e^{i(k_m-k_l)})</span> yields irregular conductance oscillations, accompanied by local current profiles with distinct periods inside and outside the well. By contrast, for <span>(t'=0.20t)</span>, only the lowest <span>(p=0)</span> conduction subband lies above the Fermi level. Although a quantum well activates additional subbands inside the well, the total transmission can be reorganized into an effective single-mode Fabry–Pérot form, <span>(G=(2e^2/h)sum _i|t_{00}|^2)</span>, yielding periodic conductance oscillations with the local current confined to the well. A similar picture holds for hole-type carriers at <span>(t'=0.15t)</span> at <span>(E_F=-1.5, textrm{eV})</span>. Finally, we note that, the next nearest-neighbor hopping breaks band symmetry, producing a convex region in the band structure. This asymmetry leads to a non-uniform local current distribution. When the Fermi level intersects the convex region, both electron- and hole-carriers contribute to transport, which is then dominated by edge conduction, analogous to chiral edge channel transport in quantum Hall systems.</p></div>","PeriodicalId":787,"journal":{"name":"The European Physical Journal B","volume":"99 4","pages":""},"PeriodicalIF":1.7,"publicationDate":"2026-04-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147737728","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":"Rejection-free Glauber Monte Carlo for the 2D Random Field Ising Model via hierarchical probabilistic counters","authors":"Luca Cattaneo,&nbsp;Federico Ettori,&nbsp;Giovanni Cerri,&nbsp;Paolo Biscari,&nbsp;Ezio Puppin","doi":"10.1140/epjb/s10051-026-01155-w","DOIUrl":"10.1140/epjb/s10051-026-01155-w","url":null,"abstract":"<p>We present an efficient Monte Carlo algorithm for the simulation of the two-dimensional Random Field Ising Model (RFIM). The method combines the event-driven, rejection-free character of the Bortz Kalos–Lebowitz (BKL) algorithm with Glauber transition probabilities, introducing hierarchical probabilistic counters to perform spin selection in <span>(mathcal {O}(log N))</span> operations. This enables efficient sampling of the system’s dynamics, especially in the low-temperature and low-disorder regime, where traditional Metropolis updates suffer from critical slowing down. Furthermore, this approach allows a proper dynamical simulation of the Ising system’s behavior even in the presence of a Random Field (RF), unlike the BKL method. RFIM simulations with Gaussian field distributions reproduce the expected reduction of the pseudo-critical temperature with increasing disorder. Benchmarking shows speedups exceeding two orders of magnitude compared to the Metropolis algorithm in the low-temperature regime. The proposed method provides an efficient and dynamically faithful tool for studying both equilibrium and nonequilibrium phenomena in disordered spin systems.</p>","PeriodicalId":787,"journal":{"name":"The European Physical Journal B","volume":"99 4","pages":""},"PeriodicalIF":1.7,"publicationDate":"2026-04-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1140/epjb/s10051-026-01155-w.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147643020","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":"Magnon interaction effects in Kitaev–Heisenberg-(Gamma ) model: a mean-field spin-wave analysis","authors":"Ke Liu,&nbsp;Fa Wang","doi":"10.1140/epjb/s10051-026-01154-x","DOIUrl":"10.1140/epjb/s10051-026-01154-x","url":null,"abstract":"<div><p>We study the effects of magnon interactions in the magnetically ordered phases of the Kitaev–Heisenberg-<span>(Gamma )</span> model, including dispersion correction and spontaneous decay rates. This model shows a rich phase diagram and is believed to describe most of the Kitaev spin liquid candidate materials. Experimentally observed spin excitation spectra in magnetically ordered Kitaev materials usually show features beyond linear spin wave theory(LSWT), which are often interpreted as signatures of proximate spin liquid states. However, magnon interactions in this frustrated model are known to produce important corrections to LSWT, including the pseudo-Goldstone mode gaps in the low energy spin excitations. In this work we employ Hartree-Fock mean-field theory augmented by perturbative corrections of magnon interactions to calculate the entire magnon dispersion and the spontaneous magnon decay in the Kitaev–Heisenberg-<span>(Gamma )</span> model. Our results reveal that the interaction-corrected magnon dispersion in the zigzag state differs significantly from LSWT. This discrepancy underscores the necessity of accounting for magnon interactions when computing spin excitation spectra under these frustrated spin models and comparing them to experimental observations.</p></div>","PeriodicalId":787,"journal":{"name":"The European Physical Journal B","volume":"99 4","pages":""},"PeriodicalIF":1.7,"publicationDate":"2026-04-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147643019","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":"Planar tunneling transistor based on 2D transition metal dichalcogenides heterostructures","authors":"Yong Guo,&nbsp;Sheng-Xiang Wang,&nbsp;Rui-Yang Yuan","doi":"10.1140/epjb/s10051-026-01159-6","DOIUrl":"10.1140/epjb/s10051-026-01159-6","url":null,"abstract":"<div><p>We investigated electron tunneling through planar heterostructures composed of two-dimensional (2D) transition metal dichalcogenides (TMDCs) modulated with an electrostatic potential induced via the gate voltage. Our results showed that resonant transmission spectra can be drastically altered by adjusting the gate voltage. When the electrostatic potential (<span>(U_{0})</span>) counteracts the effect of the band offset (<span>(Delta E_{text {c}})</span>) between two different adjacent 2D TMDC materials (so that the effective potential <span>(U_{textrm{eff}}=Delta E_{text {c}}+U_{0}approx 0)</span>), the wave-vector mismatch at the interfaces is largely compensated in our coherent-transport model and the transmission can approach unity over a broad incident-energy range. When the gate voltage is changed to make the electrostatic potential approach the negative of the band offset, the conductance shows a trend from a relatively slow increase to a rapid decrease until it approaches zero, which indicates that the planar heterostructures exhibit pronounced gate-tunable switching characteristics in the coherent regime. As the length of the middle gate-voltage-modulated layer increases, the conductance exhibits beat-like oscillations originating from Fabry–Pérot interference. This study elucidates the operating mechanism of a planar tunneling transistor based on 2D semiconducting heterostructures and provides theoretical guidance for gate-controlled tunneling transport and device design.</p></div>","PeriodicalId":787,"journal":{"name":"The European Physical Journal B","volume":"99 4","pages":""},"PeriodicalIF":1.7,"publicationDate":"2026-04-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147642598","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":"Bright–dark kink soliton transport in a spin rotator model of Heisenberg Helimagnet","authors":"A. Ludvin Felcy,&nbsp;J. Akhalya,&nbsp;M. M. Latha","doi":"10.1140/epjb/s10051-026-01156-9","DOIUrl":"10.1140/epjb/s10051-026-01156-9","url":null,"abstract":"<p>We examine the dynamics of a helimagnetic spin system in the continuum limit by introducing a spin rotator model that incorporates both anisotropic and bilinear interactions. The resulting dynamical equations of motion are derived and analyzed through analytical as well as graphical methods using the Multiple Exponential Function approach, with particular emphasis on the influence of various interaction mechanisms. The effects of lattice deformations are also explored. Furthermore, the modulational instability (MI) of the proposed magnetic spin system is investigated analytically through linear stability analysis.</p>","PeriodicalId":787,"journal":{"name":"The European Physical Journal B","volume":"99 4","pages":""},"PeriodicalIF":1.7,"publicationDate":"2026-04-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147621099","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":"MD simulation of lead-silicate glass: prospective from Buckingham and BMH potentials","authors":"Archana Shukla,&nbsp;Namrata Tripathi","doi":"10.1140/epjb/s10051-026-01150-1","DOIUrl":"10.1140/epjb/s10051-026-01150-1","url":null,"abstract":"<div><p>Lead oxide (PbO) as special materials are characterized by high refractive indices, nonlinear susceptibilities, and large infrared transmission windows, and hence, have found widespread applicability in optical devices used in electronics and optoelectronics. Lead glasses have low melting point, minor crystallization tendency upon thermal activation, and are a good radiation shielding glasses having high attenuation coefficient for gamma rays as well because heavy-metal oxides (HMO) like PbO increase the density of the glass and have a high molecular weight. The addition of lead oxide in silicate glass compositions has the potential to improve the shielding effectiveness significantly. It is a challenge therefore to investigate how these glasses can be tailored for optimal gamma ray shielding. Therefore, in order to search for a better shielding material, lead silicate glass has been simulated using the molecular dynamics simulation (melt → quench → equilibration → production) both with Buckingham and Born–Mayer–Huggins (BMH) potential with an aim to validate the use of both potentials as both of them are interchangeable albeit a change of variable, though the parameter set is different. Further, we elucidate the structure and mechanical properties by making use of the both potentials and make a careful comparison. Finally, the use of this simulated glass in nuclear radiation shielding has been commented on.</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":"99 3","pages":""},"PeriodicalIF":1.7,"publicationDate":"2026-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147607333","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 on electronic, elastic and anisotropic properties of beryllium–doped NiTi2 compound","authors":"Xumin Yang,&nbsp;Jinyu Qiao,&nbsp;Yuhao Xia,&nbsp;Xin Li,&nbsp;Nan Zhang,&nbsp;Hongsheng Zhao,&nbsp;Huanming Chen","doi":"10.1140/epjb/s10051-026-01147-w","DOIUrl":"10.1140/epjb/s10051-026-01147-w","url":null,"abstract":"<div><p>The electronic structure, formation enthalpy, mechanical and thermodynamic properties of beryllium–doped NiTi₂ were investigated via the DFT method. The effect of applied pressure taking on the elastic and Debye temperature was also analyzed. The results show that Ni₃₂(Ti_{64–<i>x</i>} + Be_<i>x</i>) has the lowest formation enthalpy and the Be atoms tend to occupy the Ti site preferentially forming a strong Ni–Be bonds. The elastic properties indicated that the deformation resistance and shear resistance of the substitutional system Ni₃₂(Ti_{64–<i>x</i>} + Be_<i>x</i>) have been improved obviously while the ductility of the interstitial system Ni₃₂Ti₆₄Be_<i>x</i> with lower doping concentration has been enhanced greatly. The value of Pugh’s ratio and Poisson’s ratio of Ni₃₂(Ti_{64–<i>x</i>} + Be_<i>x</i>) indicated that the ductility is increased with applied hydrostatic pressure being increased. The Debye temperature <span>(Theta_{{text{D}}})</span> and the lattice thermal conductivity <span>(kappa)</span> have the same trend as that of Young's modulus of Ni₃₂(Ti_{64–<i>x</i>} + Be_<i>x</i>) with hydrostatic pressure change.</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":"99 3","pages":""},"PeriodicalIF":1.7,"publicationDate":"2026-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147607334","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 physical approach to local energy injection control of neural networks","authors":"Chunni Wang,&nbsp;Binchi Wang,&nbsp;Zhao Lei,&nbsp;Jun Ma","doi":"10.1140/epjb/s10051-026-01152-z","DOIUrl":"10.1140/epjb/s10051-026-01152-z","url":null,"abstract":"<div><p>In the neural network, 5 × 5 neurons in the local area are excited by energy injection, which an additive sub-branch circuit injects energy flow into the inductive ion channel, the branch circuit composed of an inductor of the neural circuit by using memristive stimuli within a finite frequency band. A control branch circuit (sub-branch circuit) is built to shunt energy flow from the neural circuit. The memristive current is filtered by the capacitor in the sub-branch circuit, then it is injected into one branch circuit of the neural circuit for continuous energy injection, which creates an energy source in the neural network, and a target wave is induced to occupy the network. It is different from the previous schemes that local periodical forcing is imposed on the membrane potential of each neuron directly, and our scheme emphasizes energy injection into the ion channels for further regulating the membrane potentials indirectly. The control mechanism is that local energy injection into ion channels will increase the energy level of finite neurons, and energy flow is diffused to excite more adjacent neurons accompanying the emergence of a target wave. The pacemaker depends on shunting current from ion channels of local finite neuron, and local energy injection into the ion channels excites finite neurons for further inducing ordered waves. It is also different from the scheme by blocking ion channels of neurons in the local area of the neural network, and our control strategy provides a physical approach and the function of ion channels is understood.</p><h3>Graphical abstract</h3><div><figure><div><div><picture><source><img></source></picture></div><div><p>Fig. 1 Energy injection into ion channel by applying memristive current on the neural circuit.</p></div></div></figure></div></div>","PeriodicalId":787,"journal":{"name":"The European Physical Journal B","volume":"99 3","pages":""},"PeriodicalIF":1.7,"publicationDate":"2026-03-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147561285","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":"Density functional study of oxygen adsorption and absorption on Ru/Ni(100) surface for corrosion mitigation","authors":"Ihsan Erikat,&nbsp;Mannal Alkhabbas,&nbsp;Alaa Maabreh,&nbsp;Yaseen Al-Husban","doi":"10.1140/epjb/s10051-026-01149-8","DOIUrl":"10.1140/epjb/s10051-026-01149-8","url":null,"abstract":"<div><p>The design of high-performance inhibitors has garnered considerable attention and presents a significant challenge. Spin polarization Density functional theory calculations are performed to calculate the adsorption/absorption of O on Ni(100) and Ru/Ni(100) systems. Ru adsorption plays a dual role depending on its coverage, acting as an effective corrosion inhibitor at low (0.25 ML) and high (1.0 ML) coverages by electronically passivating the Ni surface, while promoting oxidation at intermediate (0.5 ML) coverage. The results predict that the inhibition/promotion of oxidation effect is influenced by the site of O adsorption/absorption and the Ru and O coverages. Oxygen atoms absorbed in the Ru monolayer-covered systems generally form stronger bonds, which may enhance surface passivation. However, this trend is interrupted in the 4Ru/2O/Ni(100) system, where the adsorption of monolayer Ru inhibits the absorption of O relative to its value at the clean Ni(100) surface.</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":"99 3","pages":""},"PeriodicalIF":1.7,"publicationDate":"2026-03-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147560527","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}