The European Physical Journal B最新文献

{"title":"Theoretical investigation of induced current in graphene layer with Rashba spin–orbit coupling","authors":"A. Naifar,&nbsp;K. Hasanirokh","doi":"10.1140/epjb/s10051-026-01223-1","DOIUrl":"10.1140/epjb/s10051-026-01223-1","url":null,"abstract":"<div><p>Our study investigates the manifestation of induced current in a single graphene layer when subjected to Rashba spin–orbit Coupling (RSOC). The process involved formulating the necessary equations for the induced current using the nonstationary density matrix method, with an omission of electron–electron interactions and any loss mechanisms. Through the exact solution of the von Neumann equation, we thoroughly investigated the influence of temperature, chemical potential, and the strength and orientation of Rashba coupling on the induced current. To the best of our knowledge, this work presents the first theoretical investigation of how the orientation of Rashba spin–orbit coupling influences the induced current in monolayer graphene. Our numerical results demonstrate the considerable influence of these parameters in effectively controlling the induced current within the graphene layer. By investigating the behavior of induced currents under different conditions, this study provides insights into the fundamental physics of the system and identifies the optimal parameters for achieving enhanced current responses. These findings can guide the design and development of more efficient and reliable electronic and spintronic devices.</p><h3>Graphical abstract</h3><p>Our study investigates the manifestation of induced current in a single graphene layer when subjected to Rashba spin–orbit Coupling (RSOC). Our numerical results demonstrate the considerable influence of these parameters in effectively controlling the induced current within the graphene layer. By investigating the behavior of induced currents under different conditions, the researchers aim to gain insights into the fundamental physics of the system and identify the optimal parameters for achieving enhanced current responses. This knowledge can guide the design and development of more efficient and reliable electronic and spintronic devices. Graphene-based structure, where the Rashba coupling can induce currents. External gate voltage can control the Rashba strength.</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":"99 8","pages":""},"PeriodicalIF":1.9,"publicationDate":"2026-08-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148751480","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":"Tuning and detection of spin change in the conductance of confined systems using the Fano–Rashba effect","authors":"Michel Mendoza","doi":"10.1140/epjb/s10051-026-01221-3","DOIUrl":"10.1140/epjb/s10051-026-01221-3","url":null,"abstract":"<p>In general, resonant tunneling peaks do not show spin change fingerprints in the conductance, which makes detectable manipulation of spin change difficult. Here we show that by changing the spatial region where the Rashba effect is applied, on the input and output sides of an open quantum dot (OQD), we can determine the spin change at the resonant tunneling peaks, this does not happen when only the intensity of the Rashba parameter is changed. The determination of the spin change is associated with an inversion of the neighboring asymmetric Fano resonance, induced by the localized Rashba effect on the sides of the OQD (Fano–Rashba effect), which can be directly observed in the conductance. We also show here that localized antidots for specific positions within of OQD control and tune spin-polarized tunneling peaks, individually and selectively. With this, we show how to generate and manipulated asymmetric Fano resonances (associated with the states of the OQD itself), for the spin-flipping detections directly in the conductance, which is important for spintronics applications, without the use of a magnetic field. Here we find, that the soft-wall confinement of OQD defines much better the tuning and manipulation of Fano resonances, in relation to the parabolic confinement, which can be used for applications in spin filters due to its greater robustness against imperfections. Our results can be tested using AFM tips in OQDs, and the effects studied can be observed in systems based on heterostructures.</p>","PeriodicalId":787,"journal":{"name":"The European Physical Journal B","volume":"99 8","pages":""},"PeriodicalIF":1.9,"publicationDate":"2026-08-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1140/epjb/s10051-026-01221-3.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148751877","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":"Thermodynamic phase transitions and criticality in dual-mode memristive networks","authors":"Emir Husain","doi":"10.1140/epjb/s10051-026-01226-y","DOIUrl":"10.1140/epjb/s10051-026-01226-y","url":null,"abstract":"<p>Biological memory is a physical phenomenon governed by thermodynamic laws, yet existing neuromorphic frameworks treat it as an algorithmic process and largely neglect the role of thermal fluctuations as an explicit physical variable. Here, we report a continuous thermodynamic phase transition in a dual-mode memristive Hopfield network under Langevin dynamics. Treating the network as a disordered spin system subject to thermal noise, we find that information consolidation does not occur gradually but through a sharp, symmetry-breaking event: below a critical noise temperature <span>(T_c approx 1.1)</span> (in natural units, <span>(k_textrm{B} = 1)</span>), the system spontaneously relaxes into a stable attractor state, analogous to the crystallization of matter. Finite-size scaling of the susceptibility peak across six network sizes (<span>(N in {64, 128, 256, 512, 1024, 2048})</span>) yields a scaling exponent <span>(gamma /nu = 1.028)</span> (95% CI <span>([0.190,,1.766])</span>), consistent with mean-field universality. The continuous nature of the transition is confirmed by four independent diagnostics: a smooth order-parameter curve <span>(langle Mrangle (T))</span>, critical slowing down of the autocorrelation time <span>(tau (T))</span>, absence of hysteresis, and a unimodal order-parameter distribution at criticality. The maximal Lyapunov exponent <span>(lambda _{max } = -alpha T &lt; 0)</span> throughout rules out deterministic chaos, establishing that the high-temperature disordered phase is thermodynamic rather than chaotic in origin. These results define a fundamental thermodynamic boundary for stable memory consolidation in physical neuromorphic substrates.</p>","PeriodicalId":787,"journal":{"name":"The European Physical Journal B","volume":"99 8","pages":""},"PeriodicalIF":1.9,"publicationDate":"2026-08-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148751464","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":"Charge transport and dielectric relaxation mechanisms in Ge₃₃Se₄₇Sn₂₀ amorphous thin films","authors":"A. A. A. Darwish,&nbsp;Saleem I. Qashou,&nbsp;E. F. M. El-Zaidia,&nbsp;Adnan Almasoudi,&nbsp;K. M. Al-Malki,&nbsp;Taghreed Alsulami,&nbsp;A. M. Hassanien","doi":"10.1140/epjb/s10051-026-01229-9","DOIUrl":"10.1140/epjb/s10051-026-01229-9","url":null,"abstract":"<div><p>The charge-transport and dielectric-relaxation mechanisms in thermally deposited Ge₃₃Se₄₇Sn₂₀ amorphous thin films were systematically investigated over a wide frequency and temperature range. The frequency-dependent conductivity follows Jonscher’s universal power law, while the temperature dependence of the frequency exponent indicates a correlated barrier hopping (CBH) conduction mechanism. The dc conductivity exhibits thermally activated behavior with an activation energy of approximately 0.17 eV, suggesting hopping of charge carriers between localized states near the Fermi level. The dielectric response was analyzed using the electric modulus formalism, revealing asymmetric relaxation peaks characteristic of non-Debye behavior and a distribution of relaxation times. The relaxation activation energy (0.29 eV) is comparable to that obtained from dc conductivity, indicating a common physical origin for conduction and relaxation processes. This correlation supports a unified description of charge dynamics governed by carrier hopping within a disordered potential landscape. The results provide insights into the interplay between localized states, hopping conduction, and dielectric relaxation in Ge–Se–Sn amorphous systems, contributing to a deeper understanding of transport phenomena in disordered semiconductors.</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 8","pages":""},"PeriodicalIF":1.9,"publicationDate":"2026-08-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148751130","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":"Non-Hermitian manipulation of the fractional Josephson effect","authors":"Tong-Yang Zhou","doi":"10.1140/epjb/s10051-026-01224-0","DOIUrl":"10.1140/epjb/s10051-026-01224-0","url":null,"abstract":"<p>We demonstrate the fractional Josephson effect in a junction formed by two topological superconducting electrodes, each supporting Majorana zero modes, coupled via two arms: one direct and the other indirect through an inserted quantum dot. It is shown that appropriate parameter configurations induce a transition from the fractional to the normal Josephson effect, due to the nontrivial role of quantum interference. The non-Hermitian mechanism arising from dephasing in the quantum dot monotonically suppresses the current amplitude when the direct-coupling arm is absent. In contrast, when both arms coexist, the non-Hermitian current-suppressing effect becomes limited, even as the dephasing strength increases. Notably, a more intriguing phenomenon emerges: this non-Hermitian mechanism can also trigger the fractional-to-normal Josephson transition, which is followed by only weak suppression of the current amplitude. These results can be helpful for understanding the non-Hermitian manipulation of the fractional Josephson effect.</p>","PeriodicalId":787,"journal":{"name":"The European Physical Journal B","volume":"99 8","pages":""},"PeriodicalIF":1.9,"publicationDate":"2026-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148751155","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":"Quench dynamics of the Kondo lattice model in ultracold Fermi gases","authors":"Kai-Yi Nie,&nbsp;Yuan-Xi Wu,&nbsp;Zhen Zheng","doi":"10.1140/epjb/s10051-026-01230-2","DOIUrl":"10.1140/epjb/s10051-026-01230-2","url":null,"abstract":"<p>The Kondo lattice model describes a many-body ground-state entangling localized moments with itinerant conduction fermions. While its equilibrium phase diagram is intensively studied, the quench dynamics remains largely unexplored. Here, in this paper, we realize the Kondo lattice model in a bipartite optical lattice loaded with ultracold Fermi gases. Deep sites host localized atoms, shallow sites carry itinerant conduction atoms, and laser fields introduce the tunable Kondo coupling. By imposing a sudden jump in the laser-induced coupling that quenches the system, we observe the coherent oscillations of the Kondo order parameter. It is the ultracold-atom analog of Higgs collective modes in a symmetry-broken gapped phase, and can be understood in analog to a two-level Rabi-oscillator model. Moreover, the evolutions are qualitatively distinct in weak- versus strong-coupling regimes. The lattice model can be implemented via the current techniques of ultracold atoms. Therefore, it can provide the controlled platform for quantum simulating and exploring non-equilibrium Kondo physics in ultracold Fermi gases.</p><p>Engineering of the Kondo lattice model and the quench dynamics of order parameters.</p>","PeriodicalId":787,"journal":{"name":"The European Physical Journal B","volume":"99 8","pages":""},"PeriodicalIF":1.9,"publicationDate":"2026-08-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148750979","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 waves and instabilities in the collinear four component antiferromagnetic materials","authors":"Pavel A. Andreev","doi":"10.1140/epjb/s10051-026-01231-1","DOIUrl":"10.1140/epjb/s10051-026-01231-1","url":null,"abstract":"<p>The small amplitude perturbations of spins are considered in the four component antiferromagnetic materials with the equilibrium state of form up-up-down-down (uniaxial samples). Other configurations for the four component antiferromagnetic materials and two component antiferromagnetic materials are briefly considered for comparison with the main regime. Dispersion dependencies of two spin waves existing in the system are found if equilibrium spins are parallel to the anisotropy axis. The dispersion equation leading to a possibility of four spin waves is derived if equilibrium spins are perpendicular to the anisotropy axis. It is found that at least one solution has a negative frequency square for all possible modules and signs of the anisotropy constants. Calculations are made for the one dimensional chain of classical spins in the approximation of the nearest neighbours interaction. Next, we also addressed the nearest neighbours interaction approximation in the limit of the continuous medium (for the Landau–Lifshitz–Gilbert equation). Mostly applied form of the Landau–Lifshitz–Gilbert equation goes beyond the nearest neighbours interaction approximation. The difference is described. Required assumptions are described.</p>","PeriodicalId":787,"journal":{"name":"The European Physical Journal B","volume":"99 8","pages":""},"PeriodicalIF":1.9,"publicationDate":"2026-08-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148751366","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":"Thermodynamics of strained graphene controlled by anisotropic Dirac velocities","authors":"L. Palma-Chilla,&nbsp;Juan A. Lazzús","doi":"10.1140/epjb/s10051-026-01228-w","DOIUrl":"10.1140/epjb/s10051-026-01228-w","url":null,"abstract":"<div><p>We investigate the thermodynamic properties of strained graphene within the anisotropic Dirac approximation. Closed-form analytical expressions are derived for the low-energy, low-temperature regime, where the Dirac description is valid. Starting from the anisotropic density of states, we obtain a unified analytical framework that relates energy fluctuations, heat capacity, entropy, internal energy, and free energy through standard thermodynamic relations. Energy fluctuations scale with temperature as <span>({(Delta E)}^{2}propto {T}^{4})</span>, leading to <span>(Delta Epropto {T}^{2})</span>, as a direct consequence of the linear density of states <span>(rho left(Eright)propto E)</span> near the Dirac point. The remaining thermodynamic quantities exhibit the expected low-temperature hierarchy, with the heat capacity and entropy proportional to <span>({T}^{2})</span>, and the internal and free energies proportional to <span>({T}^{3})</span>. A central result is that shear strain modifies all thermodynamic quantities through a single geometric factor determined by the inverse product of the anisotropic Dirac velocities, providing a simple connection between mechanical deformation and thermodynamic response. Consequently, strain systematically enhances energy fluctuations, heat capacity, entropy, and internal energy, while lowering the free energy, without altering the underlying temperature scaling laws.</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":"99 8","pages":""},"PeriodicalIF":1.9,"publicationDate":"2026-08-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148750691","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":"Anomalous transport and first-passage statistics of run-and-tumble particles with repeated trapping in disordered media","authors":"Kheder Suleiman,&nbsp;Hua Li,&nbsp;Yongge Li,&nbsp;Yong Xu","doi":"10.1140/epjb/s10051-026-01217-z","DOIUrl":"10.1140/epjb/s10051-026-01217-z","url":null,"abstract":"<p>We investigate anomalous transport and first-passage properties of run-and-tumble particles in disordered environments using a generalized renewal framework that decouples directional persistence from stochastic trapping. Unlike standard models, multiple trapping events may occur within a single run without resetting orientation. Run and trapping times are drawn from exponential or power-law distributions, enabling both Markovian and non-Markovian regimes. Exponential statistics yield ergodic ballistic-to-diffusive crossover dynamics, whereas power-law trapping (<span>(1&lt;alpha &lt;2)</span>) induces subdiffusion and weak ergodicity breaking, and power-law runs (<span>(1&lt;beta &lt;2)</span>) produce superdiffusive transport. Their interplay generates a continuum of anomalous scaling regimes and a diffusive crossover near <span>(alpha +beta approx 3.5)</span>. Despite heavy-tailed dynamics, confinement regularizes first-passage statistics, ensuring finite mean first-passage times. These results establish a minimal stochastic framework for intermittently hindered active transport and provide quantitative predictions for scaling behavior and search efficiency in heterogeneous media.</p>","PeriodicalId":787,"journal":{"name":"The European Physical Journal B","volume":"99 8","pages":""},"PeriodicalIF":1.9,"publicationDate":"2026-08-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148750915","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":"Doping and electrically driven insulator–metal transitions in V(_2)O(_3)","authors":"L. Craco","doi":"10.1140/epjb/s10051-026-01220-4","DOIUrl":"10.1140/epjb/s10051-026-01220-4","url":null,"abstract":"<p>Based on DFT+DMFT calculations, we outline a mechanism for orbital-selective insulator-to-metal transitions in paramagnetic V<span>(_2)</span>O<span>(_3)</span>, showing how they can be triggered upon electron/hole doping or under the application external electric fields, the latter inducing a charge density wave ordering. These realistic situations are shown to have profound effects on orbital switchings and current–voltage characteristic curves due to the close proximity of V<span>(_2)</span>O<span>(_3)</span> memristor to Mott transitions.</p>","PeriodicalId":787,"journal":{"name":"The European Physical Journal B","volume":"99 8","pages":""},"PeriodicalIF":1.9,"publicationDate":"2026-08-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1140/epjb/s10051-026-01220-4.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148750636","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}