Journal of Interface, Thin Film and Low Dimension Systems
Volume:5 Issue: 2, Winter-Spring 2022

In this research, the resistivity of the Bi1.66Pb0.34Sr2Ca2Cu3-xZrxO10+δ (Bi-2223) polycrystalline samples (x=0.0, 0.002, 0.0075, and 0.01) synthesized by the sol-gel method, has been investigated under magnetic fields. Also, the structural and morphological properties of ceramic superconductors have been studied by using Xray diffraction (XRD) and Field Emission Scanning Electron Microscopy (FESEM) measurements. It is found that the Bi-2223 structural phase was formed more than other phases in the synthesized samples for x≤0.0075. Based on the resistivity measurements, it is understood that the TC decreases with the increase in the Zr doping and the second superconducting transition is seen for the x≥0.0075. The thermally activated flux creep (TAFC) model has been investigated in synthesized ceramic superconductors. Furthermore, the magneto resistivity behavior of all samples has been analyzed to determine the dependence of the pinning energy with applied magnetic fields and Zr doping. It is found that the pinning energy remarkably decreases with the rise of the Zr doping. Therefore, the creeping of vortices and crossing the energy barrier occur more easily, thus the pinning energy is reduced by increasing the Zr doping. Moreover, a good agreement between the modified TAFC model and the experimental data is concluded for the synthesized compounds.

The Al zig-zag sculptured thin film consists of two identical columns, the first nanocolumns (zig) are oriented at the angle χ, and the second nanocolumns (zag) are oriented at the angle (π- χ). The optical properties of these nanostructures were obtained using the transfer matrix method for linear s- and p- polarized incident lights in the wavelength range of 300-1000 nm. The reflection and transmission spectra of the zigzag nanostructures with different arm numbers and lengths were obtained at different incident angles. The Bragg peaks begin to appear for zig-zag nanostructures of morethan 4 arms for s- polarized light at angles greater than 30. For zig-zag structures of 4, 8, and 16 arms, one, two, and three Bragg peaks were observed, respectively. However, for p- polarized light, no Bragg peak was observed at any of the incident angles. Also, for the zig-zag structure of 8 arms for s-polarized light at 60 incident angles, the number of Bragg peaks increases with increasing arm length. In addition, the peaks created in the wavelengths below 550 nm showed a red shift while the peaks that appeared in the wavelengths above 550 nm showed a blue shift.

A graphene-based-hybrid plasmonic waveguide (GHPW) with a unique geometric structure is designed for surface plasmon polariton guidance and modulation at the frequency area of 10 to 30 THz. The GHPW consists of a graphene layer in the middle, a high-density polyethylene (HDPE) gating layer, two interior dielectric delimiter layers, and two exteriors semi-cylinder Germanium substrates symmetrically embedded on both edges of the graphene. Because of the matchless semi-cylinder structure design, the electromagnetic wave interaction with graphene ultimate subwavelength SPPs strong confinement with long propagation length. Small normalized mode area of ~10-4 and long propagation length of 10.67-28.92 μm at Fermi energy of 1.0 eV is attained for SPPs modes propagation of the GHPW in the frequency bound of 10-30 THz and semi-cylinder radius R > 450 nm, respectively. By controlling the graphene Fermi energy, it is found that the structure has a modulation depth higher than 20 % for the frequency band of 10-30 THz and arrives at the peak of approximately 100 % at a frequency greater than 28.75 THz. To benefit from the great broadband MIRpropagation and modulation efficiency, the GHPW may promise different MIR waveguides, modulators, photonic, and optoelectronic devices.

In the present paper, we study the entanglement dynamics of a two-spin system withHeisenberg interaction and Dzyaloshinskii-Moriya (DM) interaction. We assume thatboth interior interactions of the system are time-dependent. We consider two differentscenarios: In the first case, both Heisenberg and DM interactions are sinusoidal functions(sin (ωt)). The findings show that if the time-dependency of both interior interactions isthe same, the quantum entanglement of the system presents more robustness and itstemporal fluctuations reduce significantly over time. In the second case, DM interactionis considered as D ∝ cos (ωt). The findings imply that this kind of time-dependencycauses the strong fluctuations of the entanglement, so that sometimes the correlationreaches zero. Therefore, in order to achieve a more stable entanglement over time, it isbetter that the time dependency of the Heisenberg interaction and DM interaction wouldbe the same.

We study the effect of the acceleration of the observer on the quantum Fisher information andentanglement using hybrid state. The two-partite entangled hybrid state consists ofdiscrete (vacuum and single photon) and continuous (coherent) variable states. When one ofthe observers (e.g., Rob) is uniformly accelerated with respect to the other partner, Alice,we find that quantum Fisher information has a more stable structure than entanglement.Results show that quantum Fisher information decreases with the increase of the accelerationbut remains finite in the limit of infinite acceleration which is in contrast with entanglement.Moreover, the effect of acceleration is investigated on the value of two-mode squeezing.

The time evolution of hard X-ray has been simulated using the NARX-GA hybrid neural network in the stable region of the plasma tokamak. Loop voltage and hard X-ray measured by the tokamak diagnostics tools were selected as network inputs. The NARX network has been trained using the Genetic Algorithm (GA) and the time evolution of the hard X-ray up to 500 μs (MSE = 4.13 × 10-5) is accurately simulated. Increasing the confinement time is the particular purpose of applying tokamak to produce energy through fusion. The real-time application of this methodology brings us closer to this goal. Hard X-ray prediction can prevent plasma energy reduction. It can also reduce the severe damage caused by runaway electrons (RE) colliding with the tokamak wall. Early prediction of hard X-ray time evolution is critical in attempting to mitigate the REs potentially dangerous effects.