The European Physical Journal D最新文献

Considering a combined Kappa–Cairns electron distribution, we have analytically explored the nonlinear dynamics of ion-acoustic solitary waves in a magnetized electron–ion–dusty plasma, encompassing both suprathermal and nonthermal aspects to provide a more realistic characterization. The Korteweg–de Vries–Zakharov–Kuznetsov (KdV–ZK) equation is developed by employing the reductive perturbation approach. The nonlinear coefficient of KdV–ZK equation disappears for certain parametric curves, resulting in modified KdV–ZK equation. The soliton solutions are derived for each case and the consequences of key physical parameters on soliton characteristics are numerically investigated. The small-k perturbation expansion approach is used to investigate the stability of solitary solutions. The numerical research on the impacts of the parameters associated with this system on the growth rate of instability predicts that the enhancements of the propagation angle and the ion gyro-frequency lead to the shrinkage of the maximum growth rate of instability. On the other hand, the enhancements of the suprathermal and nonthermal parameters associated with electron’s distribution lead to the shrinkage of the maximum growth rate of instability. Understanding wave propagation and stability in space and astrophysical dusty plasmas, such as the solar wind, magnetosheath, and wider heliospheric regions, may be improved by the present research.

Topological photonic crystals are innovative optical structures that leverage topological phases to achieve robust photonic bandgaps, exhibiting immunity to structural imperfections and disorder. However, a significant challenge in conventional topological photonic crystal designs has been the difficulty in precisely controlling the position of the transmission peak. To address this limitation, we present a modified topological photonic crystal composed of alternating (hbox {SiO}_2) and (hbox {TiO}_2) layers. This design incorporates a synergistic approach that integrates the transfer matrix method, quarter-wavelength thickness design principles, and iterative optimization of layer parameters to ensure precise wavelength alignment and enhanced spectral control. The proposed modified topological photonic crystal demonstrates superior performance, including wider photonic bandgaps, moderate transmission efficiency, and improved resistance to structural defects.

Top panel: Schematic diagrams of the proposed structure without modification (top) and with modification (bottom), together with the transmission spectra for the symmetric (red) and topological (blue) structures. Bottom panel: Transmission spectra (blue line), average transmission over perturbation (red line), and mean square error (gray shaded region) for the symmetric structure (left), topological structure (middle), and modified topological structure (right).

We perform a systematic study of the electron momentum distribution symmetry properties in electron–atom scattering assisted by an orthogonally polarized two-color laser field. We show that the dynamical symmetry of the field is imprinted onto the electron momentum distribution. In addition to the direct electron scattering off the atom, which we call the single scattering, we consider the case of rescattering where the laser field-driven electron returns and rescatters off the atom. We pay a particular attention to the role of the relative phase between the laser field components. In the single-scattering case, we identify additional symmetry properties arising from the laser field configuration. Furthermore, using the stationary phase method we derived energy conservation conditions, both for single scattering and for the rescattering. With the aid of these conditions, we assess the position of the cutoff electron energy and investigate its dependence of the laser field parameters. Our results demonstrate that the laser field parameters allow independent control of the single-scattering and rescattering plateaus. For some configurations, the rescattering plateau extends to significantly higher energies than for the single scattering.

Electron momentum distributions in the final momentum plane for (a,b) linearly polarized, (c,d) (omega )–(2omega ), and (e,f) (2omega )–(omega ) OTC fields with equal component intensities and relative phase (phi = 0^circ ). Initial energies: (E_{text {i}} = 0) eV (a,c,e) and 10 eV (b,d,f)

We propose a scheme to enhance quantum entanglement in an optomechanical system consisting of two mechanically coupled mechanical resonators, which are driven by a common electromagnetic field. Each mechanical resonator is linearly and quadratically coupled to the electromagnetic field. Moreover, the mechanical coupling between the resonators is modulated through a given phase that allows interference control in our structure. By tuning this phase, our system exhibits interference like-structure which is reminiscent of bright and dark mode features. The breaking of the dark mode via the phase adjustment leads to an entanglement generation, which is greatly enhanced through the quadratic coupling. Furthermore, the generated entanglement is robust enough against thermal noise and this resilience is improved when the quadratic coupling is accounted. Our work provides a way to enhance quantum entanglement via quadratic coupling which is assisted by interference control. Such quantum resources can be useful for quantum information processing, quantum computing, and other numerous quantum tasks.