Narrow Results

We study the vortex configuration in a superconducting macroscopic flat disk with central defects in the presence of a uniform applied magnetic field. Owing to the defects nature on the thin disk, vortices are able to form geometry induced, quasi-symmetric configurations of disk, triangle and concentric shells in the rest of the disk. The theoretical study made on this mesoscopic systems allows us to trace not only how the vortex pattern evolves with magnetic field, but also how the defect can be used to show the pinning and anti-pinning effect. The magnetic induction, vortex number, magnetization and Cooper pairs density as a function of the external magnetic field are calculated, we show that in our sample novels vortex configurations are possible due to the size of the disk and if the hole or barrier defect is considered.

We report on the influence of a circular defect on the vortex configuration in a mesoscopic superconducting sample. Effects associated with the pinning force of the circular defect on the configuration and on the vortex entry fields are studied for a very thin disk. We calculate the magnetization loop, vorticity, free energy and superconducting electrons for the disk in presence of an external magnetic field applied perpendicular to the disk plane. The magnetization curves are hysteretic, with paramagnetic response in part of the downward branch, also, in this part we found a vortex–anti-vortex state.

In this paper, we report on the influence of an internal defect on the vortex entrance in a mesoscopic superconducting sample. Effects associated to the pinning force of the defect on the configuration and on the vortex entry fields are studied for a very thin disk. We calculate the supercurrent, magnetization, vorticity, free energy and Cooper pairs density for a disk in presence of external magnetic field applied perpendicular to the disk plane. Due to vortex–defect attraction (repulsion), the vortices always (never) are found to be sitting on the defect position.

In this paper, we solve the Ginzburg–Landau equations for a circular geometry containing a half-circular pillar. We consider the surface of the sample in a complete normal state (|ψ|_surface = 0), this choice, leading to take the extrapolation de Gennes length equal to zero (b = 0). Our results point out that the critical fields, magnetization and vorticity, depend on the chosen boundary condition.

In this paper, we report on the influence of a square (triangular) trench on the superconducting properties of a perforated mesoscopic sample. Effects associated to the pinning force of the hole versus the pinning by the trench and interplay between the shape of the outer boundary and the shape of the inner defects on the vortex configuration are studied for a thin disk. Using the Ginzburg–Landau theory, we calculate the magnetization, vorticity, free energy, magnetic induction, supercurrent and superconducting order parameter as a function of the applied perpendicular magnetic field. We show that only in a restricted range of the magnetic field the vortex configuration obeys the geometry of the trench. Nevertheless, we clearly demonstrate that in our sample new phenomena are possible due to competing interactions of the geometry of the sample and the added geometry of the nanoengineered trench.

In this work, we studied the magnetization and the Cooper pairs density in a conventional superconducting thin square film in the presence of an external magnetic field H. Our investigation was carried out to solve the $p$-wave-two-band Ginzburg–Landau equations (TB-TDGL) considering a topological-type coupling between the bands. We vary the size of the sample $L$, the weighty of the coupling $\gamma$ and the effective Ginzburg–Landau parameter ${\kappa }_{\mathrm{\text{eff}}}$, as a magnetic field function. We found an interesting vortex configuration and the respective generation of vortex clusters due to the coupling used between condensates. A high (weak) dependence of the first (second) critical field on the weight of the coupling is found. We revealed interesting magnetization curves, their dependence with the size of the sample, the relationship with the coherence length and penetration length and finally with the weight of the coupling between the bands ($\gamma$).